Presentation on theme: "Chemical Handling/Hazards All Chemicals Are Hazardous PDO has 785 chemicals Rejected 22 Carcinogens 7 (e.g, Benzene, Crystalline Silica, Asbestos) A cigarette."— Presentation transcript:
Chemical Handling/Hazards All Chemicals Are Hazardous PDO has 785 chemicals Rejected 22 Carcinogens 7 (e.g, Benzene, Crystalline Silica, Asbestos) A cigarette contains >3800 – 40 Carcinogens
Chemical hazards –Chemicals are the most common and significant health hazards –Chemicals can be hazardous for numerous reasons and can combine with other chemicals to make new hazards –All hazards must be taken into account when using and storing chemicals.
Objectives To: –Recognize chemical hazards commonly encountered in the field –Explain warning properties of various chemical hazards –Describe how to evaluate and control these hazards.
The degree of hazard associated with a particular chemical will depend on: –Its physical properties –Its toxicity –The way it is used –The environment in which it is encountered.
Chemical Handling/Hazards Chemical hazards Liquids, Dust, Fume, Mist, Vapour & gas Modes of Entry Ingestion Skin Absorption/eyes Inhalation Toxicity Ability of the substance to harm the body and the manner in which it harms the body Quantity + Duration + Toxicity = Dose The dose makes the poison
Physical Classification SolidsAerosols LiquidsVapours Chemicals may be found in solid, liquid, aerosol, or gas and vapor form. The degree of danger varies according to the form of the chemical and the factors previously discussed.
Solids Not all forms of a chemical pose a health hazard. For example, a lead pipe is not a significant health hazard. However, the lead can become a human health hazard if the pipe is sanded or welded, producing lead dust or fumes. The dust or fumes can become airborne and be inhaled, or it can leach into water and be ingested.
Solids A chemical may be hazardous even in solid form. For example, individuals who are sensitized to nickel may develop dermatitis from skin contact with the metal. Fuming solids emit toxic vapors that may be inhaled. Some materials, such as pesticides, can evaporate directly from solid form. Some solids are not a hazard alone but become hazardous when they come into contact with other chemicals (e.g., acid in contact with iron can release hydrogen gas).
Aerosols Aerosol is a term used to describe fine particles (solid or liquid) suspended in air. Examples of aerosols include dust, fumes, mist, fog, smoke, and smog. Knowing how various aerosols are generated will help you anticipate where aerosol hazards may exist in the field Aerosols may be a hazard to the eyes, skin, and the respiratory system.
Liquids Many liquids are hazardous in contact with the skin. They either damage the skin or they are easily absorbed through the skin. chemicals that can damage or be absorbed through the skin and will have this effect on all skin, not just the hands. The degree of hazard associated with a liquid depends on its characteristics and how it is handled.
Liquids For example, inhalation is the primary route for a chemical to enter the body. Its vapour pressure is important in determining the liquid degree of hazard. Liquids with a low vapor pressure may create a low airborne concentration. Liquids with a high vapor pressure may produce high airborne concentrations. The hazard level of an airborne concentration depends in part on the chemical's toxicity.
Toxicity Toxicity Depends on : Amount + Duration Exposure or effect Dose Response of % dead LD50 LC50 (other routes)- (air) Dose (single exposure) 50
Exposure Route Lung Ear Eye Nose Mouth Musculo- skeletal Skin Whole body
Target Organs LungHeart Digestive tractLiver Kidneys Ear Eye Skin Nose Mouth Reproductive system CNS
Personal Protective Equipment Depends;Physical Form, (Solid, Gas, Liquid) Potential health effects (Irritancy - Toxicity) Quantity handled Method used Nominal Protection Factor Hazard Labelling Break Through Period Types =Protective Clothing Gloves Goggles Shields Hearing Protection Respirator - Air Supplied Air Purified
Control Measures Chemical Approval Panel MSDS (SHOC) Elimination Substitution Changed Method of work Engineering Control (extraction) Information, Instruction & Training Personal Protection Equipment Monitoring Recovery Measures (Emergency Plan)