WHMIS categorizes hazardous materials into specific classes to help workers recognize and manage different types of physical and chemical hazards effectively. These hazards can pose serious risks, including fires, explosions, corrosive damage, and health effects if not managed properly. Proper understanding and handling of these materials are essential to ensuring workplace safety.

Key Physical and Chemical Hazards in WHMIS

  1. Flammable and Combustible Materials
    • Description: These materials can catch fire or explode when exposed to an ignition source, such as heat, sparks, or open flames.
    • Examples: Solvents, alcohols, gasoline, and certain gases like propane.
    • Pictogram: Flame.
    • Safe Handling:
      • Store in designated areas away from heat sources.
      • Keep containers tightly sealed when not in use.
      • Use non-sparking tools and grounding devices when working with flammable materials.
  2. Oxidizing Materials
    • Description: Oxidizers release oxygen, which can intensify fires and cause other materials to burn faster or more intensely.
    • Examples: Hydrogen peroxide, nitric acid, and potassium permanganate.
    • Pictogram: Flame over circle.
    • Safe Handling:
      • Store separately from flammable and combustible materials.
      • Use in well-ventilated areas and avoid contact with incompatible substances.
      • Wear appropriate PPE, such as gloves and eye protection.
  3. Compressed Gases
    • Description: Gases stored under high pressure can cause explosions if heated, punctured, or dropped. Some gases may also be flammable or toxic.
    • Examples: Oxygen, propane, acetylene, and nitrogen.
    • Pictogram: Gas cylinder.
    • Safe Handling:
      • Secure cylinders upright and store in well-ventilated areas away from heat.
      • Cap cylinders when not in use and avoid dropping or damaging them.
      • Follow proper procedures for attaching and detaching regulators and hoses.
  4. Explosives
    • Description: Explosive materials can detonate or cause a rapid release of energy when exposed to certain conditions, such as shock, heat, or pressure.
    • Examples: Fireworks, certain peroxides, and ammunition.
    • Pictogram: Exploding bomb.
    • Safe Handling:
      • Store in approved, designated areas away from ignition sources.
      • Handle with extreme caution, following manufacturer guidelines.
      • Restrict access to trained personnel and ensure all handling procedures are followed.
  5. Corrosive Materials
    • Description: Corrosive substances can cause severe damage to skin, eyes, respiratory passages, and materials, including metals.
    • Examples: Hydrochloric acid, sodium hydroxide, and sulfuric acid.
    • Pictogram: Corrosion.
    • Safe Handling:
      • Use appropriate PPE, including gloves, goggles, and face shields.
      • Store in corrosion-resistant containers in designated storage areas.
      • Use in well-ventilated areas and avoid mixing with incompatible chemicals.
  6. Reactive Materials
    • Description: Reactive or unstable materials can undergo violent reactions, including explosion, if exposed to heat, light, shock, or water.
    • Examples: Sodium metal, certain peroxides, and lithium.
    • Pictogram: Exploding bomb (or no pictogram if classified solely as reactive under specific circumstances).
    • Safe Handling:
      • Store in cool, dry areas away from incompatible materials.
      • Avoid exposing reactive materials to conditions that can trigger a reaction.
      • Regularly inspect containers for signs of deterioration or leaks.
  7. Self-Reactive and Self-Heating Substances
    • Description: Self-reactive substances can undergo exothermic decomposition even without oxygen. Self-heating substances can spontaneously ignite if left exposed to air.
    • Examples: Some organic peroxides and chemicals like phosphorous.
    • Pictogram: Flame or exploding bomb, depending on the substance.
    • Safe Handling:
      • Store in designated areas following specific storage instructions.
      • Use PPE, including thermal-resistant gloves where necessary.
      • Ensure these materials are stored separately from flammable and combustible materials.
  8. Pyrophoric Substances
    • Description: Pyrophoric materials can ignite spontaneously upon exposure to air.
    • Examples: White phosphorus and certain finely powdered metals like iron and magnesium.
    • Pictogram: Flame.
    • Safe Handling:
      • Store in airtight containers in inert environments when possible.
      • Avoid contact with air and handle only in controlled environments.
      • Train workers on handling pyrophoric materials to prevent accidental exposure to air.
  9. Organic Peroxides
    • Description: Organic peroxides can be unstable and may cause explosive or self-reactive hazards.
    • Examples: Benzoyl peroxide, used in plastics and resins.
    • Pictogram: Flame or exploding bomb, depending on the specific hazard.
    • Safe Handling:
      • Store in cool, temperature-controlled areas away from ignition sources.
      • Handle with care to prevent shock or friction.
      • Regularly inspect containers and use appropriate PPE, including face shields and gloves.
  10. Health Hazardous Substances (Specific to Chemical Exposure)
    • Description: While not solely physical hazards, many hazardous materials used in electrical work (e.g., solvents, cleaning agents) pose health risks, such as carcinogenicity or respiratory damage.
    • Examples: Benzene, silica dust, and certain solvents.
    • Pictogram: Health hazard symbol.
    • Safe Handling:
      • Use appropriate respiratory protection and ensure adequate ventilation.
      • Avoid prolonged skin contact, and use gloves or aprons as necessary.
      • Follow SDS guidance for safe use and emergency measures in case of exposure.

General Safe Handling Guidelines for Physical and Chemical Hazards

  1. Personal Protective Equipment (PPE):
    • Always use the appropriate PPE for the hazardous material being handled, such as gloves, face shields, respirators, or aprons.
    • Consult the Safety Data Sheet (SDS) for recommended PPE.
  2. Ventilation:
    • Work in well-ventilated areas or under fume hoods when handling volatile or gaseous materials to prevent inhalation of hazardous fumes.
  3. Storage and Segregation:
    • Store materials according to their specific requirements, such as in flammable storage cabinets for combustibles or corrosion-resistant cabinets for acids.
    • Segregate incompatible materials to prevent reactions, such as keeping oxidizers separate from flammable substances.
  4. Spill Response and Emergency Preparedness:
    • Have spill kits readily available near hazardous material storage areas.
    • Ensure workers know the emergency procedures, including evacuation routes, first-aid responses, and emergency contact numbers.
  5. Training and Compliance:
    • WHMIS training is mandatory for all employees who handle hazardous materials. Training should cover the identification, safe handling, and emergency response for these materials.
    • Regularly review and refresh training to ensure compliance with current WHMIS standards and any new material introductions.
  6. Labeling and SDS Accessibility:
    • Ensure all hazardous materials are properly labeled and that WHMIS symbols are visible.
    • Make Safety Data Sheets (SDS) easily accessible to all workers, and encourage workers to review them before handling hazardous substances.

Summary

Understanding and managing physical and chemical hazards under WHMIS is essential for maintaining workplace safety in environments where hazardous materials are used. Proper handling, labeling, storage, and training are key measures for preventing accidents, injuries, and health issues associated with hazardous materials. Workers trained in WHMIS are better equipped to recognize hazards, use PPE effectively, respond to emergencies, and ensure a safe work environment for themselves and others.