Principle of Industrial Hygiene Lecture Notes PDF

DRO 1423 PRINCIPLE OF INDUSTRIAL HYGIENE LECTURER MS. NUR SYAFIQAH FAUZAN  At the end of this topic, students should be able to: ◦ identify information needed and methods used for Learning anticipation, recognition, evaluation and control the health hazard...

DRO 1423 PRINCIPLE OF INDUSTRIAL HYGIENE LECTURER MS. NUR SYAFIQAH FAUZAN  At the end of this topic, students should be able to: ◦ identify information needed and methods used for Learning anticipation, recognition, evaluation and control the health hazards found at workplace; Outcomes ◦ apply the four (4) principles of Industrial Hygiene at various workplaces.  What are the principles of Industrial Hygiene? REFRESH!!! Principles of Industrial Hygiene 1. Anticipation what are potential health hazards that may be introduced with processes or products? 2. Recognition what are existing health hazards at the workplace? 3. Evaluation how severe are the existing health hazards? Are the hazards truly hazardous? 4. Control how can the health hazards be eliminated or minimized? 1. ANTICIPATION 5  1. ANTICIPATION…When? ▪ During design or engineering stage of process or equipment ▪ During introduction of new legislations and regulations ▪ Research and development – product improvement, Design for Safety 6 Anticipation…How? ❖ Anticipate potential health hazards and health risks: ◦ Process characteristics ◦ Physicochemical properties ◦ Possible health effects ◦ Past experiences ◦ Similarity of the chemical structure to a known hazardous chemical ❖ Potential health risks are exposure to hazardous chemicals, physical agents and biological agents 7 2. RECOGNITION 8 2. RECOGNITION….How?  E.g. recognize chemical hazard through: Walk through survey – senses, observe, talk to workers, etc. Information on the identity & quantity of the chemicals being used, handled, stored or transported Document review Knowledge of the health effects of over exposure to the chemical substances Grab samples Observation of their presence in the working environment & likelihood of entering the body 9 Recognition….How? Review information on: ◦ Material ◦ Chemical registry – contains the inventory of materials used or kept at the workplace ◦ SDS – chemical substances ◦ Process ◦ Process flowchart ◦ Process description ◦ Layout plan ◦ Equipment ◦ Specification 10 Recognition…How? Workplace inspection Observe: ◦ Source of hazard  Materials flow ◦ Work practice ◦ Nature of exposure  Equipment & process operations ◦ Existing controls ✓ Use of senses  Worker’s work pattern ✓ Simple direct reading  Workplace contamination / instrument conditions 11 Recognition…How? Feedback on exposure &  Serve as: health complaints ✓ indication of other possible hazards ◦ Management & supervisors not identified through the workplace ◦ Workers observations ◦ Company doctor/industrial ✓ To correlate with the observations nurse made 12 Recognition…How? Review of health records ◦ Pre-clinical symptoms ◦ Poisoning & disease cases ◦ Prevalence 13 Recognition…How? Sketch the floor plan Identify the hazard sources Place the sources on the plan Place the receivers on the plan Show the pathways between them Consider the potential health effects 14 3. EVALUATION 15 3. EVALUATION…How? Qualitatively Estimate Quantitative measurement or sampling Exposure Frequency, duration, magnitude Apply occupational exposure standards Characterize Acceptable or not Risk To be controlled or not Qualitative Evaluation… E.g. Chemical Hazard Involve the observation of: ◦ Work practice ◦ Condition of work environment ◦ Degree of worker’s contamination (personal hygiene) 17 Qualitative Evaluation… E.g. Chemical Hazard Work method & practice Work environment Personal hygiene The way chemicals are handled Whether the air is contaminated with Important aspect for assessing Occurrence of splash chemical vapor or mist skin exposure. The degree of Use the senses to detect the presence skin contamination depends on Use of PPE of a chemical substance in the Contamination of environment (not advisable to detect a whether: skin/cloth/PPE carcinogen) PPE worn is clean before use Duration of contact with Contamination of work surface e.g. Workers wash or shower at work or at chemical workbench, tools, machinery, outside home or not at all of containers including handles Workers change into clean clothes, Decontamination of PPE including underwear  Noise level – dosimeter, sound level meter Quantitative Evaluation… Hearing level - audiometer Instrumentations Lighting – luxmeter Heat – wet bulb globe temperature, hygrothermometer Gas/Vapour - Gas detector, Drager pump, passive diffusion badge Dusts/Fumes/Mists – sampling pump, dust meter Evaluation….Exposure Limits There is a need to define occupational exposure limits below which workers may be exposed to health hazards without experiencing any adverse health effects. Useful in making a decision whether the risk is significant or not and hence the risk should be controlled Regulatory Department of OSH (DOSH) – chemicals, noise, dust Atomic Energy Licensing Board (AELB) – radiation Non-regulatory Corporate policy e.g. Shell, Exxon Mobil, Petronas etc. 4. CONTROL 21 Control… When risk is unacceptable or when exposure limits are exceeded. Purpose – to prevent or to minimise hazardous exposures to an extent such that the risk of adverse health effects is insignificant. Risks are to be controlled such that exposures are less than the PEL, except for carcinogens that do not have a ‘safe limit’. For carcinogens, the approach is to control exposures to as low as reasonably achievable. Principle of Control 01 02 03 04 Control At Eliminate Or Control Below Control Risk To Source Rather Isolate Rather Occupational As Low As Than At Receiver Than Minimise Exposure Reasonably Standards Practicable (ALARP) Hierarchy of Control Certain methodologies are preferred over others with respect to their overall effectiveness in protecting workers’ health. Control methods which do not rely heavily on workers co-operation, are generally preferred E.g. PPE requires high worker’s cooperation over those methods, which are highly worker reliance.  Elimination of hazardous substance, process or equipment from the workplace; Control by any/combination Substitution with a less hazardous substance, process of… or equipment; Isolation of the source from the receiver – segregation by distance or barrier; Minimization of risk – engineering methods e.g. enclosure, general ventilation, local exhaust ventilation (LEV), and water spray; Administrative procedures – safe & hygienic work practices & procedures, use of PPE, personal hygiene Approach of Control The best – control at source PPE is the last resort of defence except when the other approaches are not possible or inadequate. Approaches to control risk: ◦ Eliminate or reduce hazard at the source of release/generation of the hazardous substance or agent ◦ Intervention at the path taken by the substance or the agent to reach the receiver ◦ Protect the receiver or the exposed person Hazard Control  Eliminate or reduce hazard at  Intervention at the  Protect the the Source Path Receiver 27 Source Controls Substitution Process Change Process Enclosure Process Isolation Wet Methods Local Exhaust Ventilation Adequate Maintenance Program 28 Pathway Controls Housekeeping General Exhaust Ventilation Dilution Ventilation Distance Continuous Area Monitoring Adequate Maintenance Program 29 Receiver Controls Training & Education Rotation Enclosure of Worker Personal Monitoring Devices Personal Protective Devices Adequate Maintenance Program 30 Example 31  Adequacy of control measures The control measure is considered adequate if it is… ◦ suitable for the purpose intended for; ◦ effective in reducing exposure according to the design of the control equipment; and ◦ regularly maintained 32