chemical-safety-ppt 2024.pdf

CHEMISTRY FOR ENGINEERS CHEMICAL SAFETY BY CHEREL M. DE LEON At the end of this unit, the students are expected to: Cognitive: Identify and classify a hazardous chemical’s class and type. Demonstrate ways to assess and manage the hazards associated with chemicals. Describe the hazards s...

CHEMISTRY FOR ENGINEERS CHEMICAL SAFETY BY CHEREL M. DE LEON At the end of this unit, the students are expected to: Cognitive: Identify and classify a hazardous chemical’s class and type. Demonstrate ways to assess and manage the hazards associated with chemicals. Describe the hazards symbols in GHS Hazard Classification and Pictograms. Affective: Listen attentively during class discussions. Demonstrate tact and respect when challenging other people’s opinions and ideas Accept comments and reactions of classmates on one’s opinions openly and graciously. Psychomotor: Participate actively during class discussions and group activities Express opinion and thoughts in front of the class CHEMICAL SAFETY is the application of the best practices for handling chemicals and chemistry processes to minimize risk, whether to a person, facility, or community. It involves understanding the physical, chemical, and toxicological hazards of chemicals. Chemical safety is the practice of handling chemicals in a safe manner, minimizing the hazard to public WHY CHEMICAL Chemicals have SAFETY its own inherent hazards. Understanding of the potential hazards and precautions prevents exposure to chemicals and mishaps.  Definition of Terms Chemical - any element, chemical compound, or mixture of elements and/or compounds. Types of Chemicals A. HAZARDOUS CHEMICALS – are substances that can cause adverse health effects such as poisoning, breathing problems, skin rashes, allergic reaction, allergic sensitization, cancer, and other health problems from exposure. Many hazardous chemicals are also classified as dangerous goods, these can cause fire, explosions, corrosion, and hazardous reactions if not handled properly. B. Non-Hazardous chemicals include all other that do not fit the definition of hazardous substances. Example of Hazardous Chemicals Paints, drugs, cosmetics, cleaning chemicals, degreaser, detergents, gas cylinders and refrigerant gases. Characteristics of Hazardous Chemicals: Ignitability or something flammable Corrosively or something that can rust or decompose. Reactivity or something explosive Toxicity or something poisonous A hazardous substance is a material or substance that poses a physical or health hazard. Health Hazards occur when a chemical produces an acute or chronic health effect on exposed individuals. Physical properties of a substance determine a Physical Hazard. Physical Hazard Examples: Xylene is an organic chemical compound. It is also known as Xylol. It is primarily used as a solvent (a liquid that can dissolve other substances) in the printing, rubber, and leather industries. Along with other solvents, xylene is also widely used as a cleaning agent, a thinner for paint, and in varnishes. A substance is pyrophoric if it ignites spontaneously in air at or below 54 °C or within 5 minutes after coming into contact with air. Examples are iron sulfide and many reactive metals including plutonium and uranium, when powdered or thinly sliced Peroxide Formers are a class of chemicals with high instability and are one of the most dangerous chemicals used in laboratories. Shock, heat, or friction can cause unexpected explosions of peroxide forming chemicals. Since peroxide crystals form on the lid and detonate when the cap is twisted, it is advised not to open a container if you suspect the formation of peroxides. Some common classes of compounds that form peroxides include Ethers, Tetrahydrofuran, Aldehydes, and Acetals. Health Hazard Examples: Nephrotoxin: A toxic chemical that damages the kidneys (e.g., Cisplatin, Aminoglycoside, Antibiotics, Indomethacin). Hepatotoxin: A toxic chemical that damages the liver (e.g., Ethanol, Halothane, Carbon Tetrachloride). Teratogen: A toxic chemical that causes malformation of an embryo (e.g., Alcohol). Acute vs. Chronic Acute Hazards cause immediate harm (e.g., Carbon Monoxide poisoning, Cyanide inhalation, etc.). Chronic Hazards do not cause immediate harm (e.g., Mesothelioma from Asbestos exposure, lung cancer from smoking, etc.). Routes of Exposure The four routes of exposure are ingestion, inhalation, injection, and skin contact. Toxicity The degree to which a toxic chemical can cause damage. Dosage, duration, and exposure to chemicals affect toxicity. B. NON-HAZARDOUS CHEMICALS that have been determined to be non- hazardous waste. It includes paper, metals, and chemicals, as well as other materials generated by industrial, commercial, agricultural and residential sources. NON-HAZARDOUS LAB CONSUMABLE WASTE ITEMS Uncontaminated gloves Empty plastic chemical containers Pipettes Centrifuge tubes Fraction collection tubes Disposable flasks COMMON CLEANING AGENTS Water, the most common cleaning agent which is a very powerful polar solvent. Soap or detergent Ammonia Solution Calcium hypochlorite Citric acid Sodium hypochlorite Sodium hydroxide Acetic acid The hazard symbols are provided only as a guide for quick recognition of the acute hazards associated with our chemicals. THE CLASSIFICATION OF HAZARDOUS CHEMICALS CLASS 1: EXPLOSIVES Division 1.1: Substances and articles which have a mass explosion hazard Commonly transported Class 1 Dangerous Goods include ammunitions, fireworks, and fuse, etc. CLASS 2: GASES It covers compressed gases, liquefied gases, dissolved gases, refrigerated liquefied gases, mixtures of gases and aerosol dispensers/articles containing gas. There are 3 sub-divisions: Division 2.1: Flammable gases Division 2.2: Non-flammable, non-toxic gases Division 2.3: Toxic gases Commonly transported class 2 dangerous goods include oxygen, natural gas, carbon dioxide, lighters, and aerosols. CLASS 3: FLAMMABLE AND COMBUSTIBLE LIQUIDS Are flammable liquids with flash points no more than 60 celcius degrees. It covers liquid substances, molten solid substances with a flash point above 60 celcius degrees and liquid desensitized explosives. Commonly transported class 3 dangerous goods include acetone, adhesives, paints, gasoline, perfume, ethanol, methanol and some pesticides with flammable solvents. CLASS 4: FLAMMABLE SOLIDS Include flammable solids, substances liable to spontaneous combustion and substances which, in contact with water, emit flammable gases. There are three sub-divisions: Division 4.1: Flammable solids Division 4.2: Substances liable to spontaneous combustion Division 4.3: Substances which, in contact with water, emit flammable gases Commonly transported class 4 dangerous goods include sulfur, matches, activated carbon, alkali metals and some metal powders. CLASS 5: OXIDIZING SUBSTANCES, ORGANIC PEROXIDES Are oxidizing substances and organic peroxides. There are 2 sub-divisions: Division 5.1: Oxidizing substances Division 5.2: Organic peroxides Commonly transported class 5 dangerous goods include hydrogen peroxide, potassium permanganate, sodium nitrite, ammonium nitrate fertilizers and oxygen generators. CLASS 6: TOXIC SUBSTANCES AND INFECTIOUS SUBSTANCES Are toxic substances and infectious substances. There are 2 sub-divisions: Division 6.1: Toxic substances Division 6.2: Infectious substances Commonly transported class 6 dangerous goods include cyanides, lead compounds, phenol, cresols, some pesticides, biological samples and clinical wastes. CLASS 7: RADIOACTIVE MATERIALS Are radioactive materials. There is no sub-division. However, there are different labels for radioactive materials which depend on the content and activity of such materials. Commonly transported class 7 dangerous goods include enriched uranium, radioactive ores, isotopes and some medical equipment or parts. CLASS 8: CORROSIVES Are corrosive substances. There is no sub-division. Corrosive substances may cause severe damage when in contact with living tissue such as skin or damage or destroy surrounding materials in case of leakage. Commonly transported class 8 dangerous goods include acids such as sulfuric acid, strong bases such as sodium hydroxide, batteries and its fluids. Health Hazards: Acute Toxicity Toxic chemicals produce injurious or lethal effects upon contact with body cells due to their chemical properties. The toxic effects depend upon the extent of exposure and the inherent toxicity of a chemical. eg: sodium-cyanide, sodium azide and dimethyl mercury Health Hazards: Irritant A chemical which is not corrosive but causes reversible inflammatory effect on living tissue by chemical reaction on place of contact. eg: KOH, NaOH, FeCl3, CH3COOH, KMnO4 Health Hazards: Irritant A. Skin Irritant Skin irritation means the production of reversible damage to the skin following the application of a test substance for up to 4 hours. B. Eye Irritant Eye irritation means changes in the eye following the exposure to the substance, which are fully reversible within 21 days of application. Health Hazards: Irritant C. Sensitization Skin sensitizer means a substance that will induce an allergic response following skin contact. The definition for “skin sensitizer” is equivalent to “contact sensitizer”. Health Hazards: Corrosive Corrosive substances causes destructive burns on the tissue by chemical action at the site of contact.  Corrosive effect can also occur in the respiratory tract in case of inhalation and in the gastrointestinal tract in case of ingestion. eg: HCl, KOH, NaOH, HF, H2CrO4, H2SO4 HOW TO PREVENT INCIDENTS FROM HAZARDOUS CHEMICALS ? A. Labelling The original label of the chemical is the best source of information to acquire knowledge about the hazards, emergency information, and storage. Original labels are required to have the following: Product Identifier Supplier Identification Precautionary Statements Pictograms Signal Words: (Danger or Warning). Danger means there is a severe hazard present and warning there is a moderate to low hazard present. Hazard Statement Supplemental Information Safety Data Sheets (SDS) A safety data sheet (SDS) is a document that must be provided to you with all hazardous chemicals. It provides useful information on the chemical hazards, advice on safe handling, use and storage, and the emergency measures to be followed in case of an accident. SDS will contain: Chemical Name and Identification Hazard Identification: Pictograms and Signal Word Personal Protective Equipment (PPE) Disposal Requirements B. Control measures for chemical hazards 1. Elimination: Discontinue the use of the hazardous chemical. 2. Substitution: Replace the hazardous chemical with a less hazardous substance. 3. Engineering Controls: Isolate people from the hazardous substance. 4. Administrative controls: Change the way people work. 5. PPE: Protect people with personal protective equipment. C. 4 Tips in Chemical Safety 1. Understand the chemicals you are using. The first and most critical aspect of using chemicals safely is to understand exactly what you are dealing with.... 2. Provide the correct PPE. 3. Store chemicals safely.... 4. Train staff thoroughly. Exercises: Write what type of Chemical Hazard of the Following elements or compounds: Potassium cyanide, sodium hydroxide, Uranium. Carbon Tetrachloride and Nitrogen. end