OSHCHM01 Chemical Safety Core Module (30 Nov 2022).pdf

Chemical Safety Training ©©Copyright CopyrightNational NationalUniversity UniversityofofSingapore. Singapore.All AllRights...

Chemical Safety Training ©©Copyright CopyrightNational NationalUniversity UniversityofofSingapore. Singapore.All AllRights RightsReserved. Reserved. 1 Welcome to the Chemical Safety Training. You can choose to pause anytime during the presentation and continue at your convenience. 1  Scope This training is for: i. all students (FYP, UROP, Postgraduate) doing research projects* involving use of chemicals ii. all lab, technical, veterinary and research staff who are performing activities* involving use of chemicals. iii. all Principal Investigators who are supervising individuals mentioned in the above two categories. *Includes work conducted in non-NUS organizations (A*STAR, Hospitals, Industrial Attachments, etc) © Copyright National University of Singapore. All Rights Reserved. 2 This training is intended for all students, staff and the supervisors of those who will be using chemicals in their research activities, even if the research activities take place outside of NUS. 2  Contents I. Introduction II. Regulatory and NUS Requirements III. Hazards of Chemicals and Consequences of Exposure IV. Control Measures and Safe Practices V. Incident Management and Emergency Response VI. Conclusion © Copyright National University of Singapore. All Rights Reserved. 3 Topics on regulatory and NUS requirements, the hazards of chemicals and the consequences of exposure will be covered. Following that, appropriate control measures and safe practices on handling chemicals, response to emergency situations will be covered. There will also be an assessment at the end of this training. 3  I. Introduction © Copyright National University of Singapore. All Rights Reserved. 4 Introduction of this training 4  Chemical Lab Explosion Associated Press and WHEC-TV Pyrophoric Chemical Fire Los Angeles Times and US Chemical Safety Board Accidental Lab Poisoning Associated Press © Copyright National University of Singapore. All Rights Reserved. 5 All chemicals can be handled safely, some simply require more care in handling than others. Improper handling can cause accidental poisoning and serious accidents such as a fire or explosion. Lives have been lost as a result. 5  Safety & Health Culture “If our students do not see and experience safety & health best practices being implemented in the university, they will also most likely enter the workforce ignorant of safety & health issues. So, in NUS, our responsibility to maintain high safety standards is even greater.” Prof Tan Chorh Chuan President National University of Singapore More information on NUS Safety Culture: Click here © Copyright National University of Singapore. All Rights Reserved. 6 Accidents can be prevented through having the right mindset towards safety and health. Therefore in NUS, safety and health is embraced as one of our core values. The importance of incorporating safety and health practices in our work is emphasized here by our senior management. We would like you to embrace this safety culture, where everyone cares about safety, thinks about safety and behaves safely. 6  Defining “Safety Culture” for Universities Advancing Safety Culture in the University Laboratory Safe Science: Promoting a Culture of Safety Creating Safety Cultures in in Academic Chemical Research Academic Institutions © Copyright National University of Singapore. All Rights Reserved. 7 To have a better understanding on creating a sustainable safety culture on campus, you may refer to the publications provided. 7  Objectives At the end of this training, participants will be aware of the: i. Regulatory and NUS requirements for chemicals ii. Hazards and risks of chemicals iii. Control measures and safe practices for handling chemicals iv. Basic response to chemical emergencies © Copyright National University of Singapore. All Rights Reserved. 8 At the end of this training, you will have an understanding of the various regulatory requirements associated with the use of chemicals and the hazards of chemicals You will also learn how to implement control measures and safe practices in order to handle chemicals safely and have some knowledge on how to respond in the event of an emergency. 8  II. Regulatory and NUS Requirements © Copyright National University of Singapore. All Rights Reserved. 9 We will now go through the regulatory and NUS requirements associated with chemicals. 9  Regulations 1. All laboratory-based activities are governed by the Workplace Safety & Health Act (WSHA), which is enforced by the Ministry of Manpower (MoM). WSHA also has specific regulations regarding chemical use and handling. 2. Depending on the type of chemical you use, they may be governed by different regulators. © Copyright National University of Singapore. All Rights Reserved. 10 The workplace safety and health (or WSH) Act is applicable to all activities in the lab and workplaces. It is enforced by the Ministry of Manpower. The WSHA also has specific regulations regarding chemical use and handling. Depending on the type of chemical you use, they may be governed by different regulators. 10  Workplace Safety & Health (WSH) Regulations Conduct Risk Assessment Identify hazards & WSH (Risk Management) Regulations control measures 1. Requirements for Medical Surveillance WSH (Medical Examinations) Regulations 2. Requirements of safety data sheets (SDS) 3. Permissible exposure levels (PEL) WSH (General Provisions) Regulations © Copyright National University of Singapore. All Rights Reserved. 11 Risk assessment must be conducted for all laboratory activities. The conduct of a risk assessment is a systematic way of identifying hazards posed to the person while performing an activity. Appropriate control measures must be implemented to protect the person from the hazards identified. We will learn more about risk assessment in the next slide. The requirement for medical examinations are specified by the WSH (Medical Examinations) Regulations. Chemical suppliers are required by law to provide the safety data sheet (SDS) of the chemicals. We will learn more about SDS later during this training. Another regulation, the WSH (General provisions) regulations stipulate the limit of exposure levels to chemicals by staff and students. 11  Risk Assessment Severity X Likelihood = Risk Level 1. Hazard Identification 3. Risk Control No Description/Detail Hazards Possible Accident / Existing Risk Control (Mitigation) Severit Likelihood Risk Additional Person By s of Steps in Ill Health & Persons- y (Probability Level Risk Control Responsible (Date) Activity at-Risk ) 1 Sample Preparation Skin contact with Dermal contact i) Safe working procedures of - pouring (37%) corrosive causes skin burns. handling HCl is developed. hydrochloric acid hydrochloric acid Person-at-risk: ii) Researcher must undergo all 2 1 2 -- -- -- into beaker as a result of researcher handling relevant training spillage. HCl iii) Lab coat, nitrile gloves must be worn Eye contact with Severe eye damage i) Safe working procedures of corrosive which may lead to handling HCl is developed. hydrochloric acid blindness. ii) Researcher must undergo all 3 1 3 -- -- -- as a result of Person-at-risk: relevant training spillage. researcher handling iii) Eye goggles must be worn. HCl Inhlation of toxic Inhalation causes i) Fume hood will be used during fumes of respiratory tract conduct of experiement. hydrochloric acid irriation, inflammation, i) safe working procedures of or pulmonary edema. handling HCl and use of fume hood 2 1 2 -- -- -- Person-at-risk: is developed. researcher handling ii) Researcher must undergo HCl, and nearby co- relevant training. workers 2 3 Hazards Accident or ill-health Control measures © Copyright National University of Singapore. All Rights Reserved. 12 A sample risk assessment is shown here. During the risk assessment, you will identify the 1. Hazard of the chemical, describing the potential to cause harm. 2. The possible accident or ill health that exposure can cause. 3. Control measures (such as fume hood, personal protective equipment) to reduce exposure Control measures must be implemented so that exposure is reduced to as low as reasonably practicable. Once the hazard, consequence of exposure and control measures are identified, the risk level can be determined through severity and likelihood ratings, this will be detailed in the next slide. 12  Risk Assessment Likelihood Ranking Guide Severity Ranking Guide Likelihood Unlikely (1) – has not occurred in the PI's Likely Possibly Unlikely Low (1) – requiring first Lab or similar Lab aid treatment only, etc Low 3 2 1 setup. Severity Medium (2) – requiring Possibly (2) – has Med 6 4 2 occurred in the PI's medical treatment, etc Lab or Similar Lab High (3) – Fatal/Serious High 9 6 3 setup injury or life-threatening occupational disease, etc Likely (3) – has occurred repetitively in RISK LEVEL DECISION PROCESS the PI's Lab or similar 4 Additional Risk Control Required Attend ORMC’s risk management training © Copyright National University of Singapore. All Rights Reserved. 13 In this slide, we see a 3 by 3 risk matrix. The severity and likelihood ratings are assigned with reference to the respective ranking guides. The numbers shown in the risk matrix are the corresponds to the risk level, which is obtained from the multiplication of the severity and likelihood ratings. An activity with a risk level below 3 is acceptable and may proceed. Additional risk control measure should be considered for activities with a risk level of 3 or 4. Activities with risk levels more than 4 must not proceed until additional risk control measures are implemented and the risk level re-assessed. You may attend the risk management training conducted by the Office of Risk Management and Compliance (ORMC) to learn how to conduct a risk assessment. 13  Safety Data Sheet (SDS) 1. 16-section document that provides information of the chemical, including the: i. hazards, ii. safe handling and storage methods, iii. emergency response procedures. SDS shall be made available to all lab members © Copyright National University of Singapore. All Rights Reserved. 14 In determining the hazard and control measures when working with chemicals, it is important you refer to the SDS of the chemical. The SDS is a 16-section document that provides important information of the chemical such as the: health and physicochemical hazards, safe handling and storage methods, emergency response procedures. The SDS of the chemicals used must be made available to all members in the lab. 14  Other Chemical-Related Regulations Regulators governing chemicals: 1. Chemical Weapons (Singapore Customs) 2. Controlled Drugs (Health Sciences Authority) 3. Explosive Precursors (Singapore Police Force) 4. Hazardous Substances (National Environment Agency) 5. Petroleum & Flammable Materials (Singapore Civil Defence Force) 6. Poisons (Health Sciences Authority) © Copyright National University of Singapore. All Rights Reserved. 15 Different regulators govern the possession and use of various types of chemicals. We will now go through regulations associated with these chemicals. 15  Chemical Weapons 1. A total of 43 chemicals or groups of chemicals are regulated. 2. The list of chemical weapons: Click here for link to website 3. These chemicals must not be purchased or used without the approval from ORMC. © Copyright National University of Singapore. All Rights Reserved. 16 Singapore Customs controls chemicals that can be weaponised under the Chemical Weapons (Prohibition) Act. A total of 43 chemicals or groups of chemicals are regulated. The list of chemical weapons can be found on Singapore Customs’ website. These chemicals must not be purchased or used without the approval from ORMC. 16  Drugs 1. Controlled drugs (such as ketamine) i. License required for import ii. Approval required for possession and use iii. Maintain a register book iv. Kept under lock and key 2. Equipment, materials & substances useful for the manufacturing of drugs are regulated. i. Permit required for import 3. The list of regulated chemicals: Click here for link © Copyright National University of Singapore. All Rights Reserved. 17 The Health Sciences Authority regulate the possession, import, export, manufacture and use of controlled drugs (such as morphine, ketamine) under the Misuse of Drugs Act. Approval is required for possession and use of controlled drugs. A register book must be maintained. All controlled drugs must be kept under lock and key at all times. Central Narcotics Bureau (CNB) regulate the import and export of controlled equipment, material and substances that are useful for the manufacturing of controlled drugs. A permit is required for the import of these controlled chemicals. 17  Explosive Precursors 1. A licence is required for the possession of explosive precursors (EP). 2. Information on EP: Click here for link to website 3. EP must be kept under lock and key. 4. Establish and maintain a register book which shall contain details of each transfer of EP. © Copyright National University of Singapore. All Rights Reserved. 18 Under the Arms and Explosives Act enforced by Singapore Police Force (SPF), a licence is required for the possession of explosive precursors (EP). Examples of commonly used EP are hydrogen peroxide, nitrates and perchlorates. The list of EP can be found on SPF’s website. EP must be locked to prevent unauthorised access. A register book must be maintain and it shall contain the following information: The date of each transfer or supply of EP The description, quantity and concentration of the EP The name and identification number of the person using the EP 18  Hazardous Substances 1. A permit is required to store and/or use any hazardous substance. 2. Information on hazardous substances: Click here for link to website © Copyright National University of Singapore. All Rights Reserved. 19 The Environmental Protection and Management (Hazardous Substance) Regulations is enforced by NEA. A permit is required to store and/or use any hazardous substance. Examples of commonly used hazardous substances in the lab are hydrochloric acid and sodium hydroxide. The full list of hazardous substances can be found on NEA’s website. A license is required if you choose to import these chemicals from foreign suppliers. 19  Petroleum & Flammable Materials (PFM) 1. SCDF regulates: i. diesel and all petroleum (hydrocarbons) with a flash point less than 60°C. ii. mixture of chemicals with a flash point of less than 60°C (including waste chemicals) iii. flammable materials based on a scheduled list. 2. Information on PFM: Click here for link to website © Copyright National University of Singapore. All Rights Reserved. 20 Under the Fire Safety (Petroleum and Flammable Materials) Regulations, SCDF regulates: diesel and all petroleum (hydrocarbons) with a flash point less than 60°C. mixture of chemicals with a flash point of less than 60°C (including waste chemicals) flammable materials based on a scheduled list. Some examples of commonly used flammable materials are metal hydrides and tetrahydrofuran. The list of regulated chemicals can be found on SCDF’s website. 20  Requirements for Flammable Liquid Storage in Laboratory Maximum Allowable Quantity (MAQ) Maximum storage Per lab limit per lab unit 500 Litres Total storage within lab 1.6 Litres (labs without sprinklers) (ie quantity on bench top and x 750 Litres within flammable safety floor area (m2) cabinet) (labs with sprinklers) 1. The exact MAQ of the lab unit is prescribed by the qualified person (QP). 2. Max quantity within each flammable safety cabinet is restricted to 250L 3. Max quantity on bench top: 10% of MAQ. © Copyright National University of Singapore. All Rights Reserved. 21 Amount of Petroleum and Flammable Materials stored must be within the Maximum Allowable Quantity (MAQ) and meet the storage requirements as stipulated by SCDF. Each lab unit can only stored a quantity of flammable liquid equivalent to 1.6 times that of floor area based on the layout plan approved by SCDF. Each lab unit can only store up to a maximum of 500litres if it is not equipped with a sprinkler system. Those which are protected by a sprinkler system can store to a maximum of 750litres. It is important to note that each flammable safety cabinet is restricted to 250 litres of flammable liquid storage. Also, the maximum quantity allowed on bench top, in fume hoods or any other cupboard that is NOT a flammable safety cabinet is 10% of the lab’s MAQ. 21  Requirements for Gas Storage in Laboratory Flammable Gases 170L for 50 m2 and less MAQ = 3.4 x Lab unit area (for labs > 50 m2) Oxidising Gases MAQ is halved for 170L for 50 m2 and less labs without a sprinkler system MAQ = 3.4 x Lab unit area (for labs > 50 m2) Liquefied Flammable Gases 30L for 50 m2 and less MAQ = 0.6 x Lab unit area (for labs > 50 m2) Toxic Gases 8L for 50 m2 and less MAQ = 0.16 x Lab unit area (for labs > 50 m2) © Copyright National University of Singapore. All Rights Reserved. 22 The following formulas are used to calculate the MAQ for types of gases for each lab unit area. The MAQ is reduced by half for labs not protected by a sprinkler system. In addition, cylinders containing different categories of gas must be stored separately from each other. 22  Poisons 1. A licence is required for the import of poisons. 2. Poisons must be kept under lock and key. 3. Information on poisons: Click here for link to website © Copyright National University of Singapore. All Rights Reserved. 23 The Poisons Act is enforced by the Health Sciences Authority (HSA). A licence is required for the import of poisons. Do not import them without prior approval from the Faculty Safety and Health Officer and licence applied for. Examples of commonly used poisons are dimethyl sulfoxide and chloroform. All poisons must be kept under lock and key in a drawer or cupboard solely reserved for their storage. The poisons list can be found on HSA’s website. 23  Laboratory Waste 1. Sewerage and Drainage (Trade Effluent) Regulations 2. Environmental Public Health (Toxic Industrial Waste) Regulations Licensed waste collector shall be engaged to collect hazardous waste. © Copyright National University of Singapore. All Rights Reserved. 24 Sewerage and Drainage (Trade Effluent) Regulations mandates that no hazardous substances can be discharged down the sink or drain. This is enforced by the Public Utilities Board (PUB). The Environmental Public Health (Toxic Industrial Waste) Regulations enforced by National Environment Agency requires hazardous lab wastes to be disposed by licensed waste collectors. 24  NUS Requirements 1. University Safety & Health Policy can be viewed at https://nusu.sharepoint.com/sites/corporate/procedures/safety_and_heal th/Policy/University%20Safety%20and%20Health%20Policy.pdf 2. The legal requirements and best practices for the safe handling of chemicals are detailed in the NUS chemical safety manual which can be viewed at https://nusu.sharepoint.com/sites/corporate/procedures/safety_and_heal th/Chemical-Safety-Manuals/Manual-chemical-safety.pdf © Copyright National University of Singapore. All Rights Reserved. 25 The roles and responsibilities for ensuring chemical safety are mentioned in the safety and health policy. The legal requirements and best practices for the safe handling of chemicals are detailed in the chemical safety manual. The policy and manual can be viewed at the respective web-links provided. 25  Responsibilities (PI & Lab Supervisors) Responsibilities include: i. conducting risk assessment for all activities and ensuring the hazards are communicated, ii. ensuring all reasonably practicable hazard control measures are implemented, iii. ensuring control measures implemented are effective in minimizing the risk, iv. ensuring staff and students receive adequate instructions on the safe handling of chemicals and have undergone the required training, and v. conducting a chemical inventory check every 6 months © Copyright National University of Singapore. All Rights Reserved. 26 Responsibilities of the PI and Lab Supervisors include: conducting risk assessment for all activities and ensuring the hazards are communicated, ensuring all reasonably practicable hazard control measures are implemented, ensuring control measures implemented are effective in minimizing the risk, ensuring staff and students receive adequate instructions on the safe handling of chemicals and have undergone the required training, and Conducting a chemical inventory check every 6 months. 26  Responsibilities (Chemical Users) Responsibilities include: i. following all laboratory safety rules, regulations, and standard operating procedures, ii. reviewing and understanding chemical hazards and hazards of laboratory procedures prior to conducting work, iii. utilizing appropriate measures to control identified hazards, including the consistent and proper use of engineering controls, administrative controls and personal protective equipment and iv. completing all required health and safety training. © Copyright National University of Singapore. All Rights Reserved. 27 Responsibilities of all chemical users include: following all laboratory safety rules, regulations, and standard operating procedures, reviewing and understanding chemical hazards and hazards of laboratory procedures prior to conducting work, utilizing appropriate measures to control identified hazards, including their consistent and proper use of engineering controls, administrative controls and personal protective equipment and completing all required health and safety training. 27  1. Need to know more about regulations governing chemicals? Refer to the NUS legal registry: https://inetapps.nus.edu.sg/osh/portal/general_safety/legalreq.html 2. Unsure which regulation/national authority governs the chemical you are using? Online Regulated Material Identifier (ORMI): https://wws.nus.edu.sg/rci/Pages/Select.aspx?nav=10 © Copyright National University of Singapore. All Rights Reserved. 28 Should you need to find out more about the local regulations concerning lab-based activities and the use of chemicals, you may access the NUS legal registry via the web-link provided. ORMC has developed a tool, the Online Regulated Material Identifier or ORMI, to assist researchers to identify the regulatory authority and the associated requirements of each chemical. Where necessary, ensure that the relevant license has been obtained before procurement of the chemical. The online regulated material identifier can be accessed via the web-link provided or from ORMC webpage. 28  Can you recall...... Which type of chemicals is required by local regulations to be kept under lock and key? A) Flammable liquids B) Liquefied flammable gases C) Corrosive chemicals D) Poisons Incorrect Correct - Click anywhere to continue Correct answer is ‘D’ Click anywhere to continue Submit Clear © Copyright National University of Singapore. All Rights Reserved. 29 29  Can you recall...... A register book containing the information of each chemical transfer and its user must be maintained for A) Explosive precursors B) Flammable liquids C) Flammable solids D) Hazardous substances Incorrect Correct - Click anywhere to continue Correct answer is ‘A’ Click anywhere to continue Submit Clear © Copyright National University of Singapore. All Rights Reserved. 30 30  III. Hazards of Chemicals and Consequences of Exposure © Copyright National University of Singapore. All Rights Reserved. 31 The use of chemicals to enhance and improve life is a widespread practice worldwide. But alongside the benefits of these chemicals, there is also the potential for adverse effects to people or the environment. We will now cover the hazards of chemicals. 31  Classification of Chemicals Globally Harmonized System (GHS) 1. Standardising the classification and labelling of chemicals 2. Defining hazards of chemicals 3. Communicating the hazard information © Copyright National University of Singapore. All Rights Reserved. 32 The Globally Harmonized System or GHS is adopted in workplaces in Singapore. GHS is a system for standardising the classification and labelling of chemicals. It is a comprehensive approach to: Defining health, physical and environmental hazards of chemicals; and Communicating hazard information, as well as protective measures, on labels and Safety Data Sheets (SDS). 32  Physical Hazards of Chemicals © Copyright National University of Singapore. All Rights Reserved. 33 We will now learn about the various physical hazards associated with the use and storage of chemicals. 33  Physical Hazards of Chemicals Explosive i. chemical that causes a sudden, almost instantaneous release of pressure, gas, and heat when subjected to shock, pressure, or high temperature. ii. contamination can cause some chemicals to become unstable and/or potentially explosive. An explosion in University of Missouri, June 2010 American Chemical Society © Copyright National University of Singapore. All Rights Reserved. 34 One of the physical hazards of chemicals is their explosive nature. It can cause great damage if not handled appropriately. Certain chemicals are capable of that causes a sudden, almost instantaneous release of pressure, gas, and heat when subjected to shock, pressure or high temperature. There are some chemicals which can become unstable and potentially explosive as a result of contamination. 34  Physical Hazards of Chemicals Explosion during an organic synthesis reaction, under elevated pressure and temperature conditions, in an inappropriate apparatus. Explosion shattered glassware and the window of the fume hood. © Copyright National University of Singapore. All Rights Reserved. 35 The photo shows the result of an explosion of a sealed reaction vessel which injured two researchers. The explosion also shattered the glassware around the experimental setup and the sash of the fume cupboard. The conduct of experiment at elevated temperature and pressure conditions, together with the use of inappropriate equipment resulted in the accident. A detailed risk assessment conducted prior to the start of this experiment would have identified high pressure levels as a hazard. Appropriate control measures could be implemented to prevent the accident. 35  Physical Hazards of Chemicals Flammable i. have a low flash point. ii. Flash Point is the lowest temperature at which the chemical gives off enough vapour to form an ignitable mixture in air. ignitable mixture with a potential of flash fire or explosion Lower Flammable Limit Upper Flammable Limit © Copyright National University of Singapore. All Rights Reserved. 36 Flammable chemicals are those having a low flash point that can ignite in the presence of a spark, flame or high temperature. Recall that SCDF classifies chemicals with a flash point that is less than 61°C as flammable. The flash point is the lowest temperature at which the chemical gives off enough vapour to form an ignitable mixture in air. The flash point of a chemical can be found in the SDS. A flash fire or an explosion can occur if the vapour concentration of the chemical in air is within is within its flammable range. The flammable range is the bounded by the Lower Flammable Limits (LFL) & the Upper Flammable Limits (UFL). 36  Physical Hazards of Chemicals Pyrophoric i. ignite spontaneously upon exposure to air or moisture. ii. some examples of pyrophoric chemicals are metal hydrides, nonmetal hydrides, alkyl compounds and silane. © Copyright National University of Singapore. All Rights Reserved. 37 Pyrophoric chemicals are those that can ignite spontaneously upon exposure to air or moisture. Some examples of those commonly used in the labs are metal hydrides, nonmetal hydride, alkyl compounds and silane. 37  Physical Hazards of Chemicals Oxidizer i. Promotes combustion by yielding oxygen (ie. contribute to the magnitude of a fire). Pressurised i. Compressed gases stored in cylinders. Sudden loss of containment may result in an oxygen-deficient environment or a ‘rocket-cylinder’. “Struck by one of the heavy cylinders as they rocketed at speeds of up to 170mph” Welwyn Hatfield Times © Copyright National University of Singapore. All Rights Reserved. 38 Oxidizers are those that promote combustion or the burning of a fire. They must never be stored together with flammable chemicals. Gases kept under pressure present another physical hazard. Damage to the cylinder such as a broken valve, can trigger a sudden and very rapid loss of containment resulting in an oxygen-deficient environment or a rocket-cylinder. Such a cylinder is known to damage and fly through concrete walls and can result in fatalities. 38  Physical Hazards of Chemicals Cryogenic i. contact causes frostbite. ii. substantial volume of gas produced during vapourisation can potentially lead to an oxygen-deficient atmosphere. http://www.aps.anl.gov/Safety_and_Training/Notices/Images/li quid_nitrogen_thumb.jpg © Copyright National University of Singapore. All Rights Reserved. 39 Cryogenic liquids have boiling points less than -73ºC. The extremely low temperature is a hazard as skin contact with cryogenic chemicals will cause frost burn. All cryogenic liquids produce large volumes of gas when they vapourise. One of the commonly used cryogenic liquid in the lab is liquid nitrogen. 1 litre of liquid nitrogen vapourises into nearly 700 litre of nitrogen gas. An oxygen-deficient atmosphere can potentially form when large quantities of liquid nitrogen vapourises. 39  Physical Hazards Glassware i. Cuts due to sharp edges from broken glassware ii. Chemicals can enter body through open wounds http://i00.i.aliimg.com/photo/v1/11523692/Lab_Glassware.jpg Syringe i. Needle-stick injuries ii. Chemicals can be introduced into the body http://www.terumotmp.com/imgs/photos/1113.jpg Be trained and adopt proper techniques when handling syringes © Copyright National University of Singapore. All Rights Reserved. 40 There are also physical hazards associated with the apparatus which are used in the laboratory. Many apparatus used in the lab are made of glass. Sharp edges from broken glassware can cut the skin and introduce hazardous chemicals into the body if it was used to hold chemicals. Never use your hands to handle broken glass. Use a pair of tongs or broom and dustpan instead. The broken glass must always be disposed into the designated ‘sharps’ bin. Needle-stick injuries are wounds caused by needles that accidentally puncture the skin and chemicals may be introduced into the body as a result. As far as possible, use blunt-tip syringes. Avoid the need to re-sheath a needle to prevent injuries. 40  Health Hazards of Chemicals © Copyright National University of Singapore. All Rights Reserved. 41 We will now move on to the health hazards of chemicals 41  Health Hazards of Chemicals “Poison is in everything, and no thing is without poison. The dose makes it either a poison or a remedy.” Paracelsus (1493–1541) The degree of harm caused by the chemical depends on: i. Toxicity (chemical’s ability to cause adverse effects) ii. Dose (how much enters the body) iii. Route of exposure (how it enters the body) iv. Frequency of exposure (how often the body is exposed) © Copyright National University of Singapore. All Rights Reserved. 42 Paracelsus was a physician who founded the disciple of toxicology. He noted that it was the dose that makes the chemical a poison or toxic to the body. The chemical’s potential to cause harm depends on: The toxicity of the chemical The dose received by the person. The dose depends on the concentration of the chemical, the duration of exposure and how much is absorbed by the body. The route or how your body is exposed to the person. The frequency or how often the body is exposed 42  Health Hazards of Chemicals 1. The effects of a toxic chemical can be: i. local (causing harm at the point of contact) or, ii. systemic (causing harm at locations distant from initial point of contact, usually at a target organ). 2. Acute Health Effect (single severe exposure and rapid absorption of the substance). 3. Chronic Health Effect (prolonged or repeated exposure) © Copyright National University of Singapore. All Rights Reserved. 43 Upon exposure to a chemical, The effects of a toxic chemical on the body can be local - causing harm at the point of contact or systemic - causing harm at locations distant from initial point of contact, usually at a target organ. Acute Health Effect refers to a single severe exposure and rapid absorption of the toxic substance. Such effects are usually reversible. Chronic Health Effect refers to a prolonged or repeated exposure to the toxic substance. Chronic health effects are usually irreversible. 43  Health Hazards of Chemicals The toxic effects of chemicals can include: Hematotoxic causes disorder of the blood and blood forming tissues (eg. arsenic, cyanides) Hepatotoxic causes liver damage (eg. vinyl chloride) Nephrotoxic causes kidney damage (eg. chloroform) © Copyright National University of Singapore. All Rights Reserved. 44 Some toxic chemicals cause damage to target organs once they enter the body. Hematotoxic chemicals cause disorder of the blood and blood forming tissues Hepatotoxic chemicals cause damage to the liver while neprotoxic chemicals damage the kidneys. 44  Health Hazards of Chemicals Cytotoxic chemicals that are toxic to cells. Some cytotoxic chemicals have carcinogenic, mutagenic or teratogenic effects. Neurotoxic causes damage to the central nervous system (eg. mercury, carbon disulphide) © Copyright National University of Singapore. All Rights Reserved. 45 Cytotoxic chemicals are those that are toxic to cells. Some cytotoxic chemicals have carcinogenic, mutagenic or teratogenic effects. Neurotoxic chemicals are those that can cause damage to the central nervous system. 45  Health Hazards of Chemicals Carcinogenic cancer-causing (eg. benzene, formaldehyde) Mutagenic causes change to genetic material, usually DNA, and potentially lead to defective cells (eg. chloroprene) Teratogenic causes development malformations to an embryo or foetus (eg. lead, organic mercury) © Copyright National University of Singapore. All Rights Reserved. 46 Carcinogenic chemicals are cancer causing. Mutagenic chemicals can cause changes to genetic material and potentially lead to defective cells. Exposure to teratogenic chemicals can result in developmental malformations or birth defects. Staff and students who are pregnant should avoid handling teratogenic chemicals. 46  Health Hazards of Chemicals Allergen/Sensitizer produces an abnormally vigorous immune response after repeated exposure which may be life-threatening (e.g. chloramine, formaldehyde). Irritant causes tissue damage and inflammation at the point of contact. Asphyxiant displaces oxygen from air or deprive the body of adequate oxygen (eg. nitrogen,, carbon monoxide). © Copyright National University of Singapore. All Rights Reserved. 47 An allergen or sensitizer is a chemical that causes exposed people to develop an immune response after repeated exposure. The reaction may be as mild as a rash or as serious as an anaphylactic shock. An irritant is a chemical that can cause tissue damage and inflammation at the point of contact. An asphyxiant displaces oxygen from air or deprive the body of adequate oxygen. Death can sometimes result. 47  Health Hazards of Chemicals Corrosive cause visible destruction of living tissue at the site of contact. http://img.medscape.com/pi/emed/ckb/ophthalm http://upload.wikimedia.org/wikipedia/common http://www.dermaamin.com/site/images/clinical- ology/1189694-1215950-78tn.jpg s/0/09/Sodium_hydroxide_burn.png pic/c/chemical_cauterization/chemical_cauterization17.jpg Acids and alkalis are commonly used corrosive chemicals. © Copyright National University of Singapore. All Rights Reserved. 48 Corrosive chemicals causes visible destruction or irreversible alterations in living tissue by chemical action at the site of contact. Acids and alkalis are commonly used corrosive chemicals in the lab. 48  Exposure Routes There are 4 exposure routes through which toxic chemicals enter the body and they are: i. Dermal absorption ii. Inhalation iii. Ingestion iv. Injection (needle stick injury) http://www.pan-uk.org/pan/images/stories/exposure.jpg http://www.umbilicup.com/images/needlestick2.jp g © Copyright National University of Singapore. All Rights Reserved. 49 There are four main routes through which chemicals can enter the body and cause harm. They are: Dermal or skin absorption Inhalation Ingestion Injection 49  IV. Control Measures and Safe Practices © Copyright National University of Singapore. All Rights Reserved. 50 Control measures and safe practices are implemented to prevent exposure to chemicals by the exposure routes mentioned earlier. 50  Control Measures Control measures prevent exposure to hazardous substances. Appropriate control measures must be implemented in the following hierarchy: Most Effective 1. Elimination To be considered first 2. Substitution 3. Engineering Controls Least 4. Administrative Controls Effective 5. Personal Protective Equipment © Copyright National University of Singapore. All Rights Reserved. 51 Control measures that are effectively implemented can protect the chemical user from harm by preventing exposure. Appropriate control measures are determined after the conduct of a risk assessment and they should be implemented in the following hierarchy: 1. Elimination 2. Substitution 3. Engineering Controls 4. Administrative Controls 5. Personal Protective Equipment Elimination is the most effective and preferred method of control while the use of personal protective equipment is the least effective control measure to protect the chemical user. The control of some hazards requires the combined use of more than one control measure to reduce the hazard to the lowest level practicable. 51  Elimination Total removal of the hazard and thereby, eliminate the risk of exposure. Examples of elimination are: i. redesigning experimental procedures such that use of a hazardous chemical or a dangerous equipment is no longer required ii. using lead-free solder (eliminate risk of exposure to the toxic metal) © Copyright National University of Singapore. All Rights Reserved. 52 Total removal of the hazard and thereby, eliminate the risk of exposure. Examples of the method of elimination of hazard can implemented are: redesigning experimental procedures such that use of a hazardous chemical or a dangerous equipment is no longer required using lead-free solder (eliminate risk of exposure to the toxic metal) 52  Substitution Replacing the hazard with one of a lesser risk. Examples of substitution are: i. using a chemical that is less toxic and has a higher flash point ii. using a solvent that has a lower vapour pressure (less volatile) iii. using nanomaterials that are fixed on a matrix instead of using them in the dry, dispersible state © Copyright National University of Singapore. All Rights Reserved. 53 Substitution is the replacing of the initial hazard with one of a lesser risk Examples of how substitution can be implemented are: using a chemical that is less toxic and has a higher flash point, such using toluene instead of benzene using a solvent that has a lower vapour pressure (less volatile) using nanomaterials that are fixed on a matrix instead of using them in the dry, dispersible state to reduce or prevent potential inhalation hazards. 53  Engineering Control Implemented in the form of: i. automation of process ii. isolating hazard from persons (ie. glove box, fume hood, machine shields, barricades and interlocks) © Copyright National University of Singapore. All Rights Reserved. 54 Engineering controls is next in the hierarchy of control measures. They can be implemented in the form of automation of process, or by isolating the hazard with the use of the glove box and fume hood, machine shields, barricades or safety interlocks. 54  Engineering Control - Fume Hood i. The fume hood contain and exhaust hazardous airborne contaminants. ii. Fume hood to be tested and certified annually (Refer to fume hood certification standard). Air Flow iii. Set sash at lowest feasible height. iv. Work towards middle of hood v. Keep your face outside the plane of the hood sash. © Copyright National University of Singapore. All Rights Reserved. 55 One of the most commonly used engineering control in NUS is the fume hood. Fume hood is a ventilated enclosure designed to contain and exhaust airborne contaminants such as chemical fumes. Before using the fume hood, ensure that the fume hood has been tested and certified. The fume hood must be tested annually by a qualified professional according to a recognised international standard. When using the fume hood, the sash must be set at lowest feasible height. The sash position control the velocity of air that passes through the fume hood. The lower the sash, the better the fume hood can exhaust airborne contaminants and protect the user. Work should be done towards middle of hood. Do not handle chemicals at the edge of the fume hood to ensure the fumes are exhausted more effectively. Keep your face outside the plane of the hood sash at all times. 55  Engineering Control - Fume Hood 1. Fume hoods are not designed for chemical storage. 2. Clutter affects performance of the hood by blocking the air flow. Place large equipment on racks Demonstration of Airflow Patterns through empty & cluttered fume hoods © Copyright National University of Singapore. All Rights Reserved. 56 Take note that fume hoods are not designed for chemical storage. Clutter not only affects performance of the hood by blocking the air flow. Clutter also increases the risk of spills and accidents and also increases the risk of spills and accidents. Large equipment should be placed on blocks or racks to allow air flow under the equipment. 56  Fume Hood with approved Fire Safety Cabinet (FSC) No storage of flammable chemicals is allowed in the cabinet of the fume hood unless it is certified for storage of flammables. FM-approved label © Copyright National University of Singapore. All Rights Reserved. 57 Often, the bottom cabinet of the fume hood is used to store chemicals. However, not every one can be used to store flammables. Only cabinets that have been specially designed and certified can be used for the storage of flammables. Please take note of the indication for such an approved cabinet. 57  Administrative Control Examples of administrative controls are: i. Safe Work Practices (such as keeping equipment well-maintained, daily housekeeping). ii. Developing and implementing standard operating procedures. iii. Scheduling maintenance and high exposure operations for times when fewer workers are present. © Copyright National University of Singapore. All Rights Reserved. 58 Examples of Administrative controls include Safe Work Practices (such as keeping equipment well-maintained, daily housekeeping). Developing and implementing standard operating procedures. Scheduling maintenance and high exposure operations for times when few workers are present. 58  Administrative Control – Chemical Labeling (GHS) Every container must have its contents identified and be labeled with the appropriate GHS pictogram(s). https://nl.vwr.com/stibo/web/std.lang.all/86/79/1127867 9.jpg http://www.emdmillipore.com/INTERSHOP/static/WFS/Merck- Site/-/Merck/en_US/Freestyle/DIV- Divisional/Support/Acetonitrile-410x406.jpg © Copyright National University of Singapore. All Rights Reserved. 59 Chemical labelling is a form of administrative control. The Globally Harmonized System (GHS) adopted by NUS, is a system that defines and classifies the hazards of chemical products, and communicates health and safety information on labels. Every container must have its contents identified and be labelled with the appropriate GHS pictogram. 59  GHS Pictograms Emits Flammable Gas, Explosive Flammable, Self-Reactive, Pyrophorics Gases Under Pressure Oxidizers © Copyright National University of Singapore. All Rights Reserved. 60 The following shows the GHS pictograms used to quickly identify the hazards of chemicals which we have covered earlier. For example, a container holding a flammable chemical will be labelled with a flame, while oxidizers and peroxides are labelled with a flame over a circle. 60  GHS Pictograms Irritant, Dermal Sensitizers, Acute Toxicity (Severe) Transient Target Organ Effects Carcinogen, Corrosive Reproductive Toxicity, Target Organ Toxicity, Aspiration Hazard, Germ Cell Mutagenicity Environmental Toxicity © Copyright National University of Singapore. All Rights Reserved. 61 This slide shows the rest of the GHS pictograms. Take note that one pictogram may be used to represent a few classes of similar hazards. For example chemicals that are classified as dermal sensitizers and chemicals that are irritants both use the exclamation mark for labelling. The hazard classes shown here are not exhaustive, refer to the chemical safety manual for more information. 61  Personal Protective Equipment i. Must be suited specifically to the task ii. Must be inspected prior to each use iii. Must be worn correctly iv. Must fit properly © Copyright National University of Singapore. All Rights Reserved. 62 Personal Protective Equipment is the last resort in the hierarchy of control measures. It is also the last line of defense in protecting the user from the hazards. PPE selected must be suited specifically to the task. They must be inspected prior to each use to ensure they are in the proper condition. PPE must be worn correctly and must fit properly. Failure to observe these practices can lead to ineffective protection. 62  Laboratory Coat i. Available in various fabrics – varying degrees of protection against different hazards. ii. Use a fire-resistant laboratory coat when handling pyrophoric chemicals iii. Refer to the Guidelines on the Selection of Laboratory Coat (Appendix M of NUS Chemical Safety Manual) © Copyright National University of Singapore. All Rights Reserved. 63 Laboratory coats are available in various fabrics and the choice of lab coat depends on the hazards identified in the activity. A fire-resistant laboratory coat should be used when handling pyrophoric chemicals. You may refer to the guidelines on the selection of Laboratory Coats for more information. 63  Gloves Appropriate gloves must be selected for each work activity. No single glove will protect you against all hazards! http://www.miningsafety.co.za/dynamiccontent/77/Gloves-for-Mining-Safety © Copyright National University of Singapore. All Rights Reserved. 64 Gloves is one of the most common PPE used in the lab. Appropriate gloves must be selected to protect the user from the known hazards. Selection of gloves shall depend on: nature of work requirements for grip, dexterity, puncture or cut resistance, type and concentration of chemicals to be handled. More information on selecting the appropriate type of gloves can be accessed in the Chemical Safety Manual. No single glove will offer unlimited protection against all hazards 64  Eye and/or Face Protection i. Risk Assessment to determine the type of eye and/or face protection to be used when corrosive, infectious or injurious materials are handled (NUS Mandatory Eye and/or Face Protection Policy). ii. In research laboratories and workshops, eye and/or face protection must be worn. Safety glasses is the minimum required. iii. In teaching laboratories, staff and students should check with their supervisor on the PPE requirements. iv. PPE to conform to relevant standards (eg. SS 473, ANSI Z87, BS EN 166) © Copyright National University of Singapore. All Rights Reserved. 65 A Risk Assessment is to be conducted to determine the type of eye and/or face protection to be used. You may access the link to find out more about NUS Eye and/or Face Protection Policy In research laboratories and workshops, eye and/or face protection must be worn. Safety glasses is the minimum required. In teaching laboratories, staff and students should check with their supervisor on the PPE requirements. The PPE used should conform to relevant safety standards for eye and/or face protection. 65  Eye and/or Face Protection Safety glasses do not offer adequate protection from large splashes. http://cenblog.org/the-safety-zone/2010/06/eyes-in-the-lab/ Therefore, consider the use of safety goggles or a combination of face shield and safety goggles. Safety Face Goggles Shield © Copyright National University of Singapore. All Rights Reserved. 66 Safety glasses do not provide adequate protection for the eyes from large splashes. They do not seal to the face, resulting in gaps at the top, bottom and sides, where chemicals may seep through. Therefore, consider the use of safety goggles or a combination of face shield and safety goggles. 66  Respiratory Protection Appropriate respirator must be selected to prevent exposure to the hazard. You must be fit tested and trained before using any respirator. Not every type of respirator will protect you against all hazards! © Copyright National University of Singapore. All Rights Reserved. 67 Respiratory protection may sometimes be used in the lab. For respirators to be effective, they must: be of the correct type for the situation or hazard; fit the person using them; be worn 100% of the time when in the hazardous environment; and be properly maintained in good working condition. To ensure the respirator is a good fit to you, you have to be fit tested prior to the use of the respirator at work. Please request for fit test via ORMC intranet at Occupational Health Clinic or from your respirator supplier. The most common respirator used in the laboratory is N95 particulate respirator. Please take note that many of these particulate respirators will not provide any protection against chemical vapors. You will still be exposed to the hazards if you use the incorrect type of respirator. 67  Can you recall … … Hazard control measures can be used in combination to reduce the risk to the lowest practicable level. TRUE or FALSE? The use of a fume hood and appropriate PPE along with the adoption of a safe work procedure is a combination of multiple control measures. http://www.ishn.com/ext/resources/F ebruary2012/HEMCO-300px.jpg © Copyright National University of Singapore. All Rights Reserved. 68 Hazard control measures can be used in combination to reduce the risk to the lowest practicable level. Is the statement TRUE or FALSE? The statement is true. The use of a fume hood and appropriate PPE along with the adoption of a safe work procedure is a combination of multiple control measures. 68  Safe Practices: Chemical Storage © Copyright National University of Singapore. All Rights Reserved. 69 Safe practices help to maintain a healthy and safe research environment. We will first discuss about chemical storage. 69  Chemical Storage 1. Separation of the storage of incompatible chemicals prevent severe consequences in the event of accidental mixing or spillage. 2. Do not stockpile! Quantities should be limited to the amount necessary for the work in progress. 3. Secondary containment for all hazardous chemicals © Copyright National University of Singapore. All Rights Reserved. 70 Proper chemical storage minimize the potential of exposure to hazardous materials. It also prevents flammables from ignition. Incompatible chemicals must be stored separately to prevent severe consequences in the event of accidental mixing or spillage. Do not store chemicals alphabetically unless they have first been separated into their hazard classes. Never stockpile chemicals in your lab! Quantities should be limited to the amount necessary for the work in progress. Remember to always return the chemicals to their proper storage facility. All hazardous chemicals must be placed in a secondary containment. The capacity of the containment tray must be at least 20% of the total volume of chemicals stored within it. 70  Chart on Chemical Storage by Hazard Class Acids, Acids, Acids, Alkalis Water- Organic Oxidizers Poisons inorganic oxidizing organic (bases) reactives solvents Acids, inorganic X X X X X Acids, oxidizing X X X X X Acids, organic X X X X X X X Alkalis (bases) X X X X X X Oxidizers X X X X Poisons X X X X X X X Water- reactives X X X X X X Organic solvents X X X X X X ‘X’ indicates that chemicals should not be stored together. For more information, please refer to the chemical safety manual or the SDS of the specific chemical. © Copyright National University of Singapore. All Rights Reserved. 71 This chart provides some guidance on chemical storage by their hazard classes. The ‘X’ indicates that chemicals should not be stored together due to chemical incompatibility or legislative requirements. For example, nitric acid, which is an inorganic acid must not be stored together with acetic acid which is an organic acid nor with acetone which is an organic solvent. The chart is by no means complete, for more information, please refer to the chemical safety manual or the SDS of the specific chemical. 71  Chemical Storage Examples of consequences of reactions between incompatible chemicals: Amides + Acids (mineral, oxidizing) Generation of heat and toxic gas Alkali Earth Metals + Alcohols Generation of heat, flammable gas and potential fire. Organic Peroxides + Ketones Possible explosion. © Copyright National University of Singapore. All Rights Reserved. 72 Here are some examples of undesirable consequences as a result of reactions between incompatible chemicals. Hence it is important to properly separate incompatible chemicals to prevent more severe consequences as a result of spillage. 72  What is wrong? Combustible gas canister should be stored away from flammable liquid. All hazardous chemicals must be stored in an appropriate Improper storage as the 2.5L chemical safety cabinet with bottle is too big for the shelf. secondary containment. © Copyright National University of Singapore. All Rights Reserved. 73 Can you identify what are the hazards in this photo taken during a lab inspection? First, the flammable gas canister that is in use should be stored away from flammable liquids and all other combustibles. Unused canisters in their original packaging should be stored in the fire safety cabinet. Second, the 2.5 litre bottle is too big for the shelf. The user has to tilt the bottle before it can be taken out. This increase the chance of an accident happening and is definitely not a good practice for chemical storage. Third, all hazardous chemicals must be stored in their appropriate chemical safety cabinet with secondary containment. Flammable chemicals must be stored in a flammable safety cabinet and corrosive chemicals must be stored in a corrosive safety cabinet. 73  Chemical Storage 1. Storage of chemicals that has dual chemical properties. i. Acetic acid (corrosive & flammable) Place acetic acid bottle in a fully enclosed container and store inside a flammable safety cabinet. © Copyright National University of Singapore. All Rights Reserved. 74 Acetic acid is an example of a chemical with dual chemical hazards. It is both corrosive and flammable. As its flammability poses a greater hazard, acetic acid must be stored inside a flammable safety cabinet. By placing it in a fully enclosed secondary container, corrosion of the flammable safety cabinet is prevented. 74  Chemical Storage in Refrigerator 1. Peroxide-forming and flammable chemicals must NOT be stored in regular, domestic refrigerators. 2. Ignition sources within regular refrigerators: Only intrinsically-safe and non-sparking refrigerators can be used. © Copyright National University of Singapore. All Rights Reserved. 75 Refrigerators may sometimes be used to store chemicals. However, do take note that peroxide-forming and flammable chemicals must NOT be stored in regular, domestic refrigerators. This is because there are several ignition sources within refrigerators. Ignition sources within the refrigerator include: Switches associated with internal light and thermostat, Timers and heating elements in frost-free refrigerators, Compressor motor, Power points These ignition sources can set off a flash fire or an explosion. Only intrinsically-safe and non-sparking refrigerators can be used. 75  Chemical Storage in Refrigerator Refrigerator explosions in laboratories University of Virginia Colchester Research Facility © Copyright National University of Singapore. All Rights Reserved. 76 These photos show the aftermath/consequences of refrigerator explosions in laboratories. Laboratories which purchase intrinsically-safe and non-sparking refrigerators should request the vendor to provide a certificate of proof that the equipment meet internationally recognized standards. 76  Safe Practices: Management of Compressed Gas Cylinders © Copyright National University of Singapore. All Rights Reserved. 77 Next is the management of compressed gas cylinders 77  Management of Compressed Gas Cylinders 1. Cylinders shall be individually strapped or chained against a wall or bench or placed in a cylinder stand. 2. Keep the cylinder valve closed when not in use. 3. Toxic, flammable and corrosive gases should be stored in a gas cabinet. © Copyright National University of Singapore. All Rights Reserved. 78 The hazards of compressed gas cylinders are discussed earlier. Unstable placement may cause the cylinder to fall and release the pressurized gas. To prevent accidents from occurring, cylinders shall be individually strapped against a wall or bench or placed in a cylinder stand. Keep the cylinder valve closed when not in use. Never place cylinders on their side. Toxic, flammable and corrosive gases should be stored in a gas cabinet. The gas cylinders must be stored away from heat sources and sources of ignition. 78  Safe Practices: Chemical Transport © Copyright National University of Singapore. All Rights Reserved. 79 Safe practices of chemical transport 79  Chemical Transport 1. Improper transportation of chemicals and chemical waste can result in spills. 2. Avoid transporting chemicals through crowded areas. 3. Control measures shall be implemented when chemicals and chemical waste are transported. © Copyright National University of Singapore. All Rights Reserved. 80 Chemical transport refers to the moving of chemicals, including chemical waste from one location to another. Improper transportation of chemicals and chemical waste can result in accidents. Avoid transporting chemicals through crowded areas. This is to minimize exposure to staff and students in the event of any chemical spillage. Risk assessments shall be conducted and control measures shall be put in place when transporting chemicals. For example, a break-resistant, secondary container can be used to transport a bottle of chemical from one lab to another within the same building. 80  Chemical Transport Use an approved chemical trolley when transporting large quantities of chemicals. Chemical-resistant material Compartments to capture and contain chemical spills Lockable wheels to prevent “runaway’ incidents © Copyright National University of Singapore. All Rights Reserved. 81 When transporting large quantities of chemicals, including chemical waste, an approved chemical trolley should be used. These trolleys must have safety features such as: be made of chemical resistant material have compartments to capture and contain chemical spills and have lockable wheels to prevent “runaway’ incidents The complete list of criteria required of chemical trolleys can be obtained from the chemical safety manual. 81  Chemical Transport 1. No one must be inside the lift when it is used for chemical transport. 2. Adequate warning signage, such as a warning notice on a retractable belt shall be used during transportation. Example of the retractable belt with warning labels. © Copyright National University of Singapore. All Rights Reserved. 82 A cargo lift must be used to transport the chemicals. For buildings where there is no dedicated cargo lift, the passenger lift may be used for transportation. No one can use the lift during transportation of chemicals. Adequate warning signage, such as a warning notice on a retractable belt shall be used during transportation. An example of the retractable belt with warning labels is shown. 82  Chemical Transfer 1. Chemical transfer refers to the dispensing of chemical from one container into another. 2. Implement appropriate control measures. 3. Refer to the SDS for special precautions to be taken when handling shock- or impact-sensitive chemicals. © Copyright National University of Singapore. All Rights Reserved. 83 Chemical transfer refers to the dispensing of chemical from one container into another. Control measures such as conducting the transfer in the fume hood and wearing of appropriate PPE shall be implemented. Refer to the SDS for special precautions to be taken when handling shock- or impact-sensitive chemicals. The transferring of liquid nitrogen and other asphyxiant should be done in a well- ventilated area. 83  Safe Practices: Chemical Waste Management © Copyright National University of Singapore. All Rights Reserved. 84 We will now discuss on the safe practices of chemical waste management 84  Storage and segregation of waste 1. Chemical waste must be stored in appropriate, chemically compatible containers. 2. Containers must be closed at all times except when adding waste. They must be provided with a secondary containment. 3. DO NOT overfill the containers. © Copyright National University of Singapore. All Rights Reserved. 85 Proper storage and segregation of incompatible laboratory waste is vital to safety in the laboratory. Chemical waste must be stored in appropriate, chemically compatible containers. Avoid the accumulation of waste. Flammable waste count towards the allowable maximum storage quantity in the lab specified by the SCDF. Containers must be closed at all times except when adding waste. All containers must be provided with a secondary containment to contain leaks and spills. Containers must not be overfilled, leave at least a 10% head space to allow for expansion. 85  Chemical Waste Labelling Each waste container must be labelled with: i. Complete contents of the container ii. Chemical composition iii. Date of waste generated iv. Hazard labels v. Contact information vi. Special precautions in handling and storage Important: No Abbreviations! Sample hazardous waste label provided by ORMC © Copyright National University of Singapore. All Rights Reserved. 86 Container holding hazardous substances must be labelled. The waste container is no exception. Each waste container must be labelled with the following information: The contents of the container and its chemical composition Date of waste generated The appropriate hazard labels Contact information of person who generated the waste Special precautions in handling and storage if there are any. Remember, do not use any abbreviations in the label. This is a sample waste label that can be obtained from ORMC. You can use the waste label from ORMC, your department or from the waste disposal vendor. Most importantly, all chemical wastes bottles have to be identified and labeled. 86  Statutory Medical Examinations 1. Every individual whose work involve toxic chemicals such as arsenic and lead, must undergo: i. a pre-placement medical examination, and ii. subsequent periodic medical examinations 2. For more information on the requirements and specified chemical hazards, refer to the Chemical Safety Manual. © Copyright National University of Singapore. All Rights Reserved. 87 WSH (medical examinations) Regulations requires people whose work involve the handling of toxic chemicals such as arsenic and lead to undergo a pre-placement medical examination, and subsequent periodic medical examinations For more information on the requirements of the medical examinations and specified chemical hazards, please refer to the Chemical Safety Manual. 87  Workplace Monitoring 1. Risk-based approach in conducting workplace monitoring. 2. Conduct a Semi-Quantitative Risk Assessment (SQRA) for chemical exposure. 3. The SQRA template can be accessed via this web link. 4. Request