chemical hazard

• Chemical hazards


  Any substance that can potentially cause physical and health hazards to people or result in harm to the environment due to its chemical properties
• Level of harm from chemical hazards

  • Amount of chemical
  • Characteristics of individual
  • Time frame of exposure
  • Route of exposure
• Amount of chemical


  All chemicals are toxic at some level. Some can cause harm at very small concentrations, while others need a large amount. Even water can be deadly if consumed in large enough amounts.
• Characteristics of individual


  • Distribution & Excretion: How a substance is distributed within the body and eliminated affects its toxicity. Organ function and excretion pathways matter.
  • Health & nutritional status: Pre-existing health conditions (kidney or liver disease) impact toxicity. Pregnancy involves physiological changes that affect toxicity.
  • Life stage: Infants, young adults, and elderly adults. Infants' immature organs may affect toxicity.
  • Gender: Sex differences influence how individuals metabolize and respond to toxic substances. Hormonal variations.
• Time frame of exposure

  • Acute: Short period, typically 24 hrs. Immediate symptom due to high exposure levels.
  • Chronic: Long periods (weeks, months, years). Prolonged exposure to env/occ hazards. Lead to cumulative effect, impact health gradually over time.
  • Sub-Chronic: Acute <> chronic exposure, lasting several weeks/months. Repeated exposure to a specific chemical in a workplace setting.
  • Intermittent: Periodically, with breaks in between. Seasonal pesticide application in agriculture.
  • Continuous: Constant and uninterrupted. Eg., Living near a hazardous waste site.
• Route of exposure


  • Inhalation: Chemicals in the form of vapours, gases, mists, or particulates are inhaled into the respiratory system – bloodstream – target organs.
  • Ingestion: Through the mouth and digestive system. Eat or drink contaminated food, water.
  • Injection: Includes intravenous (IV) drug use, accidental needle sticks, or medical procedures.
  • Absorption: Through the skin (dermal exposure) or eyes (ocular exposure). Handling toxic substances without proper protection.
• Common chemical groups that cause health risks in the workplace

  • Dust, fumes & gases
  • Solvents
  • Metals
  • Acids & bases
  • Pesticides
• Classifications of chemical effects on health/safety

  • Asphyxiants
  • Corrosives
  • Irritants
  • Sensitizers
  • Carcinogens
  • Mutagens
  • Teratogens
  • Reactive
  • Flammable
• Control strategy of chemical hazards

  1. Elimination/Substitution

  2. Engineering Controls

  3. Administrative and Work Practice Controls

  4. Personal Protective Equipment (PPE)
• Hazard communication


  A right to know: What chemicals you are exposed to, Hazards of working with those chemicals, What steps you can take to protect yourself and those you work with
• Employer requirements for hazard communication

  • Compile a list – Chemical Inventory
  • Safety Data Sheet (SDS)
  • Hazardous chemicals must be labelled
  • Training program
  • Written hazard communication program
• Sections in a Safety Data Sheet (SDS)

  • Section 1: Chemical Product & Company Information
  • Section 2: Composition & Ingredients
  • Section 3: Hazard Identification
  • Section 4: First Aid
  • Section 5: Fire-Fighting
  • Section 6: Accidental Release
  • Section 7: Handling and Storage
  • Section 8: Exposure Controls & Personal Protection
  • Section 9: Physical & Chemical Properties
  • Section 10: Stability & Reactivity
  • Section 11: Toxicological Information
  • Section 12: Ecological Information
  • Section 13: Disposal Considerations
  • Section 14: Transport Information
  • Section 15: Regulatory Information
  • Section 16: Additional Information
• What must be on a hazard warning label

  • Product identifier
  • Pictogram
  • Signal word
  • Hazard statement(s)
  • Precautionary statement(s)
  • Name, address, telephone number of the chemical manufacturer or importer

  
• Indoor air quality (IAQ)


  Refers to the quality of the air inside buildings and structures, particularly concerning the health and comfort of occupants. Poor IAQ can lead to various symptoms, including headaches, fatigue, difficulty concentrating, and irritation of the eyes, nose, throat, and lungs.
• Common contributors to indoor air pollution

  • Gas cookers
  • Improper or inadequately maintained heating/cooling and ventilation systems
  • Contamination by construction materials, glues, fibreglass, particle boards, paints, chemicals, etc.
  • Increase in the number of building occupants and time spent indoors
• Common indoor air contaminants and their main sources

  • Carbon dioxide (CO2) – from building occupants and combustion of fuels such as gas and oil furnaces and heaters.
  • Carbon monoxide (CO) – from vehicle exhaust brought into the building by air intakes.
  • Dust, fibreglass, asbestos, gases, including formaldehyde – from building materials.
  • Vapours, volatile organic compounds (VOCs) – from copying and printing machines, computers, carpets, furnishings, cleansers and disinfectants, solvents, pesticides, disinfectants, glues, caulking, paints etc.
  • Dust mites – from carpets, fabric, foam chair cushions.
  • Microbial contaminants, fungi, moulds, bacteria – from damp areas, wet or damp materials, stagnant water, condensate drain pans, etc.
  • Ozone – from photocopiers, electric motors, electrostatic air cleaners.
  • Other sources: tobacco smoke, perfume, body odour, food, etc.