DRO1113 L12 - Chemical and Biological Health Hazards & Control Student Copy PDF

INTRODUCTION TO OSH (DRO1113) TOPIC 12: Biological and Chemical Health Hazards & control  LESSON OUTCOME At the end of this chapter, you will be able to: 1) Recognize the forms of, and classification of, substances hazardous to h...

INTRODUCTION TO OSH (DRO1113) TOPIC 12: Biological and Chemical Health Hazards & control  LESSON OUTCOME At the end of this chapter, you will be able to: 1) Recognize the forms of, and classification of, substances hazardous to health. 2) Distinguish between acute and chronic health effects. 3) Outline control measures that should be used to reduce the risk of ill-health from exposure to hazardous substances.  INTRODUCTION ▪ Occupational health is as important as occupational safety but generally receives less attention from managers. ▪ Illness do not usually kill people, but they can lead to many years of discomfort and pain. ▪ Such illness include respiratory disease, hearing problems, asthmatic condition and back pain. ▪ Many illness are been difficult to link with the workplace cause because it also can cause from other causes. ▪ Occupational health, unlike occupational safety, is generally more concerned with probabilities than certainties. BIOLOGICAL HAZARDS  DEFINITION ▪ Biological agent Comprises living organisms such as virus, bacteria that capable of releasing toxic materials which cause of disease. ▪ Infection Attack by a pathogenic organism, whether resulting in disease or not.  DEFINITION ▪ Host The habitat of the agent ▪ Environment Comprises living and non-living organisms (includes biosphere, atmosphere, lithosphere, hydrosphere) ▪ Bio-safety A field of science that tries to disconnect the elements in the infection chain  FORMS OF BIOLOGICAL AGENT ▪ Fungi Very small organisms, sometimes consisting of a single cell, and can appear as plants (e.g., mushrooms & yeast). Fungi reproduce by producing spores, which can cause allergic reaction when inhaled. The infections produce by fungi such as athlete’s foot, or ringworm. Many fungal infection can be treated with antibiotics. http://129.215.156.68/Images/asexual.htm http://www.mold-help.org/content/view/421/ Aspergillus Mucor  FORMS OF BIOLOGICAL AGENT ▪ Molds A particular group of very small fungi which under damp conditions, will grow on surfaces such as walls, bread, cheese, leather and canvas. They can be beneficial (penicillin) or cause allergic reactions (asthma).  FORMS OF BIOLOGICAL AGENT ▪ Bacteria Very small single-celled organisms which are much smaller than cells within the human body. They can live outside the body and be controlled and destroyed by antibiotic drugs. Bacterial diseases: legionellosis, tuberculosis and tetanus. Salmonella species Staphylococcus aureus  FORMS OF BIOLOGICAL AGENT ▪ Viruses Are minute non-cellular organisms which can only reproduce within a host cell. They are much smaller than bacteria and cannot be controlled by antibiotics. They appear in various shapes and continually developing new strains. They are usually only defeated by defense and healing mechanism of the body. Drugs can be used to relieve the symptoms of a viral attack but cannot cure it. Example of viral infection: hepatitis, AIDS (HIV), Influenza, COVID-19  CHARACTERISTICS OF BIOLOGICAL AGENTS 1. No threshold exposure limit 2. Can exist in any environment 3. Effected and influenced by biological competition  INTERACTION OF THE AGENT, HOST AND ENVIRONMENT Agent Host ❖ Vector, carrier ❖ Health status ❖ Replacement Agent Host ❖ Management of pathogens system ❖ Antibiotic ❖ Training resistance ❖ Health monitoring ❖ Virulent factors Environment ❖ Use of PPE ❖ Infection ❖ Perception factors ❖ Retention ❖ Death factors Environment ❖ Population density ❖ Medical support services ❖ Weather (wing, temperature, UV index) ❖ Social, politics and ethics ❖ Design of facilities  FACTORS FOR THE ONSET OF DISEASES 1) Pathogenic agent 2) Existence of reservoir 3) Agent capable of retention 4) Agent mobility 5) Entry in new host 6) Susceptible host  INFECTION CHAIN Pathogen Retention Release from retention Transmission through environment Route of entry Susceptible Infectious control = break any one or host more links in the infection chain  BIOHAZARD SYMBOL The term and its associated symbol are generally used as a warning, so that those potentially exposed to the substances will know to take precaution actions.  CABINET CLASSIFICATION Biohazard Risk Group Classification (used for lab work) Risk Group Definition Examples Control Risk Group ▪ A microorganism Bacteria and Normal Level 1 that is unlikely to viruses including microbiological (No/ low cause human or Bacillus Subtilis, practice individual/ animal disease. Canine Hepatitis, community risk) ▪ Pose little to no Escherichia Coli, threat of infection Varicella (chicken of healthy adult. pox), as well as some cell cultures and non-infectious bacteria.  CABINET CLASSIFICATION Biohazard Risk Group Classification (used for lab work) Risk Group Definition Examples Control Risk Group Level 2 ▪ Associated with human Bacteria and viruses that ▪ Biohazard label (moderate individual disease that pose a cause only mild disease to ▪ Autoclave risk, low community risk) moderate health hazard. humans, or are difficult to ▪ A pathogen that can contract via aerosol in a lab cause human and animal setting, such as hepatitis A, disease but is unlikely to B, C, influenza A, Lyme be a serious hazard to disease, salmonella, mumps, laboratory workers, the measles, dengue, HIV community, livestock or environment. ▪ Laboratory exposures may cause serious infection, but effective treatment and preventive measures are available and the risk of spread of infection is limited.  CABINET CLASSIFICATION Biohazard Risk Group Classification (used for lab work) Risk Group Definition Examples Control Risk Group Level ▪ A pathogen that Bacteria and viruses ▪ Specific design 3 usually causes such as anthrax, SARS ▪ Specific LEV (high individual potentially lethal virus, tuberculosis, risk, low disease through typhus, Rift Valley community risk) inhalation. fever, Rocky ▪ Effective treatment Mountain spotted and preventive fever, yellow fever, measures are and malaria. available. Among parasites Plasmodium Falciparum, which causes malaria and trypanosomiasis, also come under this level. CHEMICAL HAZARDS  FORMS OF CHEMICAL AGENT ▪ Dust Solid particles slightly heavier than air but suspended in it for a period of time. The size of particles ranges from about 0.4 μm (fine) to 10 μm (coarse). Are created either by mechanical processes or construction process or by specific task. Respirable dust (fine) – can penetrates deep into the lungs and remains there. E.g., cement, granulated plastic materials and silica dust Inhalable dust (course) – capable for entering the nose and mouth during breathing.  FORMS OF CHEMICAL AGENT ▪ Gases Any substances at temperature above their boiling point. Steam is the gaseous form of water. Common gases: carbon monoxide, carbon dioxide, nitrogen, oxygen Gases are absorbed into the bloodstream where they may be beneficial (oxygen) or harmful (carbon monoxide).  FORMS OF CHEMICAL AGENT ▪ Vapors Substances which are at or very close to their boiling temperatures. They are gaseous in form. Many solvent, such as cleaning fluids, fall into this category. The vapors, if inhaled, enter the bloodstream and some can cause short-term effect (dizziness) and long-term effects (brain damage)  FORMS OF CHEMICAL AGENT ▪ Liquids Substance which normally exist at a temperature between freezing (solid) and boiling (vapors and gases). ▪ Mists Like vapors in that they exist at or near the boiling temperature buy are closer to the liquid phase. This means that there are suspended very small liquid droplets present in the vapors. A mist produced during a spraying process (such as paint spraying). Similar effect to vapors.  FORMS OF CHEMICAL AGENT ▪ Fume Collection of very small metallic particles (less than 1 μm) which have condensed from the gaseous state. Commonly generated by welding process. The particles tend to be within the respirable range and can lead to long-term permanent lung damage. The exact nature of any harm depends on the metals used in the welding process and the duration of the exposure.  HAZARDOUS SUBSTANCES & IT RISKS Cause skin (dermatitic) or lung (bronchial) inflammation after repeated contact. Irritant e.g., bleaches, toluene, acetone, formaldehyde, ozone Ones which will attack, normally by burning, living tissue. Corrosive e.g., strong acids (sulphuric acid)or alkalis (caustic soda) Substance, if swallowed, inhaled or Harmful penetrates the skin, may pose limited health risk.  HAZARDOUS SUBSTANCES & IT RISKS Ones which impede or prevent the function of one or more organs withing Toxic the body. e.g., lead, mercury, carbon monoxide Ones which are known or suspected of promoting abnormal development of Carcinogenic body cell to become cancer. e.g., asbestos, silica Substance which damage genetic material within cells, causing abnormal Mutagenic changes that can be passed from one generation to another.  EFFECT OF HAZARDOUS SUBSTANCE ▪ The effect on health of hazardous substances may be either acute or chronic. Acute effects Chronic effects Short duration and appear Develop over a period of rapidly, usually during or time which may extend to after a single or short-term many years. exposure to hazardous Produced from prolonged or substance. repeated exposure to Effect may be severe and hazardous substances require hospital treatment resulting in a gradual, latent but are usually reversible. and often irreversible illness. E.g., asthma-type attacks, E.g., cancers and mental nausea, fainting diseases  ROUTE OF ENTRY ▪ Principles route of entry of hazardous substances into the human body. Inhalation Absorption Ingestion Injection  BODY SYSTEM, TOXICANTS & EFFECTS System Toxicant Effects The respiratory Respirable dust Fibrosis, bronchitis, asthma system (asbestos, coal, silica, talc) The nervous system Trichloroethylene & Loss of memory anxiety, mercury epilepsy, narcosis The cardiovascular ▪ Benzene Blood cell production system decrease ▪ Carbon monoxide Reduce O2 in blood The urinary system ▪ Xylene Liver too active or inactive ▪ Alcohol Cirrhosis ▪ Vinyl chloride Liver cancer The skin Sensitizer & allergen irritant contact dermatitis (chemical, mineral oils, Allergic contact dermatitis solvents)  HEALTH HAZARDS OF SPECIFIC AGENTS 1) Cancer – is a serious body cell disorder in which the cells develop into tumors. 2 types of tumours: o Benign – localized and grow slowly o Malignant – spreading to other organs and grow rapidly 2) Occupational asthma – cause by breathing in respiratory sensitizers Agent: wood dusts, organic solvent, solder flux fumes, animal hair Symptoms: coughing, wheezing, tightness of the chest, breathlessness due to a constriction of airways.  HEALTH HAZARDS OF SPECIFIC AGENTS 3) Ammonia – is a colorless gas with a distinctive odor, even in small concentrations, can cause the sore eyes and tightening of the chest. Corrosive substance – can burn skin, eye, throat, bronchitis Most work on ammonia plant should require a permit-to work procedure. 4) Chlorine – greenish, toxic gas with a pungent smell Highly irritant to the respiratory system – severe bronchitis, oedema of the lung Used as a disinfectant for drinking water and swimming pool water and in the manufacture of chemicals  HEALTH HAZARDS OF SPECIFIC AGENTS 5) Organic solvent – used widely in industry as cleansing and degreasing agents. 2 main groups: hydrocarbon (toluene, white spirit) non-hydrocarbon (trichloroethylene, carbon tetrachloride) Sensitizers and irritant, can cause dermatitis 6) Carbon dioxide – colourless and odourless gas which is heavier than air. Causing death by asphyxiation Hazard occurs in confined space  HEALTH HAZARDS OF SPECIFIC AGENTS 7) Isocyanates – VOC, used for products such as printing inks, adhesives, paints and plastics Irritants and sensitizers. Inflammation of nasal passages, throat and bronchitis 8) Asbestos – crocidolite (blue), amosite (brown) and chrysotile (white). Blue and brown asbestos can be found in older building (heat insulator, hot water pipes) White asbestos used in asbestos cement product and brake lining Can lead to asbestosis, fibrosis, lung cancer, and mesothelioma  HEALTH HAZARDS OF SPECIFIC AGENTS 9) Lead – heavy, soft and easily worked metal. Used in plumbing and roofing work. Target organ: spinal cord, brain, blood, bone marrow Symptom: headaches, nausea, followed by anaemia, muscle weakening and coma. 10) Silica – main component of most rocks and a crystalline substance made of silicon and oxygen Silica dust can lead to silicosis, fibrosis and pneumoconiosis  HEALTH HAZARDS OF SPECIFIC AGENTS 11) Leptospirosis – cause by bacterium found in the urine of rats Causing high temperatures and headaches followed by jaundice. It can be fatal 12) Legionella – airborne bacterium and is found in a variety of water sources (cooling tower, evaporative condenser). It produces a form of pneumonia caused by the bacteria penetrating to the alveoli in the lungs. Known as Legionnaires’ disease  HEALTH HAZARDS OF SPECIFIC AGENTS 13) Hepatitis – a disease of the liver and can cause high temperatures, nausea and jaundice Cause by some organic solvent and virus Precautions include good personal hygiene.  DUTIES OF EMPLOYERS ▪ Employers must take undertake a suitable and sufficient assessment of the health risks created by work. ▪ Employers must prevent or control the exposure of their employees to substances hazardous to health. ▪ Employer must maintain any installed control measures on regular basis, keep suitable records and review system of work. ▪ Monitoring must be undertaken of any employee exposed to item listed in Scheduled 1 of USECHH 2000 regulation. Record monitoring kept for at least 30 years.  DUTIES OF EMPLOYERS ▪ Health surveillance must be provided to any employee exposed to any substances listed in Scheduled 2 of USECHH 2000 regulation. Record monitoring kept for at least 30 years. ▪ Emergency plans and procedures must be prepared to deal with accidents or incidents involving exposure to hazardous substances beyond normal day-to-day risks. ▪ Employees who may be exposed to substances hazardous to their health must be given information, instruction and training sufficient for them to know the health risks created by exposure and the precautions which should be taken. PREVENTING/ CONTROLLING MEASURES OF HAZARDOUS SUBSTANCES ▪ Elimination of the substance ▪ Substitution of the substance (or the reduction in the quantity use) ▪ Total or partial enclosure of the process ▪ Local exhaust ventilation ▪ Dilution or general ventilation ▪ Reduction of the number of workers exposed to a strict minimum ▪ Reduce time exposure by task rotation and the provision of adequate breaks  PREVENTING/ CONTROLLING MEASURES OF HAZARDOUS SUBSTANCES ▪ Good housekeeping ▪ Training and information on the risks involved ▪ Effective supervision to ensure that the control measures are being followed. ▪ PPE (such as clothing, gloves and masks) ▪ Welfare (including first aid) ▪ Medical records ▪ Health surveillance LOCAL EXHAUST VENTILATION Common elements of a simple LEV system  RESPIRATORY PROTECTIVE EQUIPMENT Respirators Filtering half mask (N95) Full-face mask respirator Half-mask respirator Powered respirator  RESPIRATORY PROTECTIVE EQUIPMENT Breathing apparatus Self-contained breathing apparatus (SCBA) Fresh air hose apparatus  SAFETY DATA SHEET (SDS) Information relating to a hazardous chemical supplied and chemical mixtures. Consists of 16 sections Meet Globally Harmonized System (GHS) requirements. GHS – to determine nature and relative severity of hazard of chemical substances or mixture. Validity of SDS – 5 years  SAFETY DATA SHEET (SDS) SDS consists of 16 sections: 1. Identification and supplier 9. Physical and chemical properties 2. Hazards identification 10. Stability and reactivity 3. Composition 11. Toxicological information 4. First aid measures 12. Ecological information 5. Firefighting measures 13. Disposal considerations 6. Accidental release measures 14. Transport information 7. Handling and storage 15. Regulatory information 8. Exposure control/ personal 16. Other information protection  LABELLING ▪ Responsibility of both supplier ▪ Information in label need to supply in national language and English language ▪ Ensure every packaging of hazardous chemicals is labelled legibly and indelibly with: ✓ Product identifier ✓ Supplier identification ✓ Signal word ✓ Hazard statement ✓ Hazard pictogram ✓ Precautionary statement  CHEMICAL REGISTER An employer shall identify and record in a register all chemicals hazardous to health use in the place of work. Chemical register need to update time to time (chemical changes, quantity changes, yearly). Accessible to all workers who may be exposed to CHTH.  PERMISSIBLE EXPOSURE LIMIT (PEL) Permissible exposure limit means a ceiling limit or an eight-hour time-weighted average airborne concentration or the maximum exposure limit. Time-weighted average in relation to airborne concentration, means an average airborne concentration over a specified period of time. Ceiling limit means the airborne concentration that should be not exceeded during any part of the working day. Short term exposure limit (STEL) means a fifteen-minutes time weighted average airborne concentration that shall not be exceeded at any time during a workday, even if the time- weighted average airborne concentration is within the time- weighted average limit. ASSESSMENT OF RISK TO HEALTH  ASSESSMENT OF RISK TO HEALTH Full assessment – using method of CHRA Simple assessment – using method of SiRAC Assessment team o Assessor (team leader) o Assisted by one or more following team members: An experienced and knowledgeable member of the safety and health committee An occupational health doctor An engineer in related field An industrial/ occupational health nurse, or Supervisor of the work area  PERSONAL HYGIENE Washing hands before partaking of food by hand. Do not eat, drink or keep food and drinks in the work area where CHTH are in used. Keeping fingernails shorts and clean. Bathing or change of clothes, where contamination is widespread.  EXPOSURE MONITORING PROGRAMME Conducted to evaluate the extent of workers’ exposure to CHTH and adequacy of existing control measures at the workplace. Air monitoring is conducted using valid method of monitoring and analysis to measure the airborne concentration of CHTH work area. Biological monitoring – test the presence of hazardous substances in a person’s biological materials (e.g., body tissue, blood, urine, breath) in order to determine how much chemical has entered the following exposure.  MEDICAL SURVEILLANCE PROGRAM Is conducted to periodically monitor worker’s health effect and determine adequacy of existing control measures. Includes physical examination and medical investigation Valid techniques for detecting indication of the identifiable disease Shall be conducted by the OHD with valid registration from DOSH  MAINTENANCE & EMERGENCY CONTROL Maintenance will involve the cleaning, testing and possibly, the dismantling of equipment. It may require a permit-to-work procedure to be in place since the control equipment will be inoperative during the maintenance operations. Records of maintenance should be kept for at least 5 years.  MAINTENANCE & EMERGENCY CONTROL Point to consider when develop emergency procedures: ✓ The possible results of a loss of control (e.g., lack of ventilation) ✓ Dealing with spillages and leakage (availability of effective absorbent materials) ✓ Raising the alarm for more serious emergencies ✓ Evacuation procedures, including the alerting of neighbours ✓ Fire fighting procedures and organization ✓ Availability of respiratory protective equipment ✓ Information and training THANK YOU