Hazardous Chemicals

Chapter 7 of the Work Health and Safety Regulations 2012 

Every year over 2000 Australian workers die as a result of occupational exposure to hazardous substances. Only 30 – 40 of these are due to poisoning, many of the other deaths result from long latency e.g. Cancer.

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 What are hazardous chemicals?

Hazardous substances are substances that have the potential to harm people’s health in the medium or long term. They can be solids, liquids or gases, and when used in the workplace, they are often in the form of fumes, dusts, mists and vapours.

Examples of hazardous substances include:

• acute toxins such as cyanide,
• substances harmful after repeated or prolonged exposure such as mercury and silica,
• corrosives such as sulphuric acid and caustic soda,
• irritants such as ammonia,
• sensitising agents such as isocyanates and
• carcinogens (cancer causing substances) such as benzene and vinyl chloride.
  

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 How can exposure affect your health?

Hazardous substances can be inhaled, ingested or absorbed through the skin and can cause both immediate and long-term health problems. Health effects depend on the type of hazardous substance and the level of exposure. Some of the potential health effects can include:

irritation sensitisation cancer poisoning nausea and vomiting headache chest pains

skin rashes, such as dermatitis chemical burns birth defects disorders of the lung, kidney or liver nervous system disorders birth defects

Injuries and symptoms are also dependant on a variety of variables including: length, quality and frequency of exposure, history and method of exposure, training received, sensitivity to the substance, general health and height and weight.

Occupational Health, Safety and Welfare legislation’s require employers in consultation with employees, to assess the level of health risk associated in working with hazardous substances.

To make a suitable and sufficient assessment you should:

• Know what the substance is.
• Know whether the substance is hazardous or not.
• Know how the substance is used (and misused) in the work process.
• Know if there is a chance of a person being exposed to the hazardous substances, how much they are exposed to, for how long and how often they are exposed.
• Know how to use this knowledge to assess the risk to a persons health.

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Labels and Material Safety Data Sheets
Manufacturers and importers of hazardous substances are legally obligated to provide warning labels and Material Safety Data Sheets (MSDS) with their products.

Employers must ensure that the Material Safety Data Sheet for each hazardous substance used in the workplace is available to workers, and that a central register of hazardous substances is established. The warning label on a product might feature cautionary words such as corrosive, poison or hazardous. For substances produced in the workplace e.g. by products or emissions for which there is no label or MSDS, the employer will need to check the NOHSC List of Designated Hazardous Substances and other resources to find out if it is hazardous.

The Material Safety Data Sheet lists important information on handling the product safely, including:

• Potential health effects
• Precautions for use
• Safe storage and handling suggestions
• Advice on how to clean up a spill
• Emergency first aid instructions
• Contact numbers for the supplier.

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Safe storage of chemicals
Safe storage of chemicals is important in any industry, however in the agriculture and rural industry there are factors such as children and animals to consider. Suggestions for the safe storage of chemicals include:

• Always follow the manufacturers instructions for proper storage.
• Keep chemicals in their original containers and don’t decant into smaller bottles.
• Do not remove labels from containers and never put chemicals into an unmarked bottle or a bottled labelled for a different substance.
• Store chemicals in a well ventilated shed (separate from the ventilation used for the workplace), fitted with locks and floors that will not allow seepage.
• Keep chemicals away from protective equipment.
• Separate different classes of chemicals to prevent reactions. One chemical alone may not be harmful but stored next to another may make it a hazard.
• Store animal feeds, seeds and fertilisers separately from chemicals.
• Check shelving requirements are the chemicals flammable, and should not be stored on metal shelves, oxidising agents may cause wooden shelves to burn.
• Have mop-up materials on hand, such as sand or soil.
• Keep ignition sources well away from chemicals.
• Keep a record of the chemicals you buy, store, use and replace.
• Used, diluted or mixed chemicals should never be returned to the original container as this will contaminate the whole container.
• Hazardous substances should be isolated from workers in separate storage areas.
• Use suitable PPE (Personal Protective Equipment) when handling or moving chemicals.

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 Hierarchy of Chemical Risk Control–
Elimination
Eliminate the use of a hazardous substance by using a physical process instead of a chemical one.

• Using ultrasound to clean equipment instead of a process involving chemicals.

Substitution
Use a safer substance or a safer form of the substance. Examples:

• Use detergent instead of chlorinated solvent for cleaning or use water-based chemicals instead of solvent-based where compatible.
• Paint with a brush instead of spraying and use pellets instead of powder that reduces the amount of dust formed.
• Purchase a substance in a safer from e.g. less concentrated liquids in ready-to-use form instead of those that require decanting and mixing.

Engineering Controls
Use physical controls (such as plant/equipment) that eliminate or reduce substances being produced, stop or contain substances or limit the area of contamination in the event of spill or leaks.

• Use fully of partially enclosed ventilation booths
• Fully or partially enclose the process with exhaust extraction
• Use local exhaust or natural ventilation systems e.g. air ducts, open windows.
• Use bunding to contain spillage
• Install drains, tanks or sumps to cope with spilled material
• Use robots

Administrative Controls
Use safe work practices including good housekeeping. Examples:

• Reduce the number of employees exposed
• Reduce the frequency, duration or exposure through job rotation
• Ensure safe interim storage of wastes/products
• Vacuum or wet mop to suppress dust being generated
• Ensure there is no eating, drinking or smoking in areas where substances are used
• Provide suitable wash and first aid facilities
• Instruct employees on the safe use of the substances and equipment
• Placement of prominent signs to warn of potential hazards

 Personal Protective Equipment
Provide personal protective clothing and equipment for employees, supervisors and visitors. These items must be compatible with the chemical being used. Examples of PPE include:

• Overalls, aprons, gowns, chemical restraint suits
• Footwear (enclosed shoes, safety boots)
• Gloves
• Chemical restraint glasses
• Face shields/masks, respirators (full/partial)
• Head protection

Personal Protective Equipment Australian/New Zealand Standards:

–       AS/NZS 1715 and 1716 Respiratory Protective Devices

–       AS/NZS 1336,1337 and 1338 Industrial Eye Protectors

–       AS/NZS 2161 Industrial Safety Gloves and Mittens

–       AS/NZS 1800 and 1801 Industrial Safety Helmets

–       AS/NZS 2210 Occupational Protective Footwear

–       AS/NZS 1270 Acoustics – Hearing Protectors

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CHEMICAL BURNS
Chemical burns are burns to internal or external organs of the body caused mainly by chemical substances that are strong acids or bases (also known as alkalies). Chemical burns that occur in the workplace are usually the result of an accident and are most commonly in manufacturing plants that use large quantities of chemicals.

The main cause of chemical burns is from contact with strong acids or bases. The strength of acids and bases is defined by the pH scale, which ranges from 1-14. A very strong acid has a pH of 1 and may cause a severe burn. A very strong base has a pH of 14 and may also cause a severe burn. A substance with a pH of 7 is considered neutral and does not burn. Chemical burns from acids or bases are also referred to as caustic burns.

The following table lists some common products containing chemical substances that may potentially cause chemical burns.

Common acids	Products
Sulphuric acid concentration ranging from 8% to almost pure acid	Toilet bowl cleaners Drain cleaners Metal cleaners Car battery fluid Fertiliser manufacturing
Nitric acid	Used in engraving, metal refining, electroplating and fertiliser manufacturing
Hydrofluoric acid a weak acid and in a dilute form does not burn or cause pain on contact	Rust removers Tyre cleaners Tile cleaners Glass etching Dental work Refrigerant
Hydrochloric acid concentrations range from 5-44%	Toilet bowl cleaners Metal cleaners Swimming pool cleaners Dye manufacturing Metal refining
Phosphoric acid	Metal cleaners Rust proofing Disinfectants, detergents Fertiliser manufacturing
Common bases	Products
Sodium hydroxide and potassium hydroxide depending on the concentration may be very corrosive	Drain cleaners Oven cleaners Denture cleaners
Sodium and calcium hypochlorite	Household bleach Pool chlorinating solution
Ammonia	Cleaners and detergents used in the dilute form is not highly corrosive Gaseous anhydrous ammonia used in fertilising manufacturing can cause severe burns
Phosphates	Many household detergents and cleaners

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Signs and symptoms of chemical burns

The signs and symptoms of a chemical burn depend on several factors, including:

• pH of the agent
• concentration of the agent
• length of contact time
• amount of agent involved
• physical form of the agent (i.e. solid, liquid, gas)
• site of contact (e.g. eye, skin, mucous membrane)
• whether swallowed or inhaled
• whether or not skin is intact

Some signs and symptoms of chemical burns to the skin include:

• Redness, irritation, or burning at the site of contact
• Pain or numbness at the site of contact
• Formation of black dead skin this occurs particularly with acid chemical burns
• Vision changes or complete loss of vision if chemicals get into the eyes

Where the agent has been swallowed, inhaled or absorbed into the bloodstream, the symptoms may be:

• Cough or shortness of breath
• Low blood pressure
• Faintness, weakness, dizziness
• Headache
• Muscle twitching or seizures
• Cardiac arrest or irregular heartbeat

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Management of chemical burns

Basic first aid should be administered as soon as a chemical burn has occurred. This should include removal of contaminated clothing and flushing the affected area with lots amounts of water. Wash for at least 20 minutes, taking care not to allow runoff to contact unaffected areas.
Chemical burns involving elemental metals (lithium, potassium, sodium and magnesium) should not be irrigated with water as this can result in a chemical reaction that causes burns to worsen. These types of chemical burns should be soaked with mineral oil while waiting for medical attention.

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HAZARDOUS SUBSTANCES

Does your job put you at risk?

Certain jobs have a notorious reputation for causing cancer. However many other jobs have a risk which is just as real, but less common. The man who delivered the milk to an asbestos factory in Canada got cancer as a result. Nurses handling cancer drugs can be at risk, and workers in newer industries, like microelectronics, may have to wait until evidence – sufficient workplace deaths – emerge before confirming the risks.

 

Cancers associated with workplace substances:

Bladder cancer: arsenic, solvents, aromatic amines, petrochemicals and combustion products, metalworking fluids and mineral oils, ironising radiation.

Bone cancer: Ironising radiation.

Brain and other central nervous system cancers: Lead, arsenic, mercury, solvents: including benzene, toluene, xylene and methylene chloride; pesticides, n-nitroso compounds.

Breast cancer: Ironising radiation, endocrine disrupters, solvents, passive smoking, PCBs, pesticides, combustion by-products, reactive chemicals including ethylene oxide, possible link to non-ironising radiation, phthalates.

Colon cancer: Limited evidence for solvents xylene and toluene, ironising radiation.

Esophageal cancer: Suggested evidence for solvent exposure particularly tetrachloroethylene, metalworking fluids.

Hodgkins disease: Solvents, pesticides, woodworking.

Kidney cancer: Evidence sketchy due to high survival rates, but some links to arsenic, cadmium and lead, solvent exposure, petroleum products, pesticides linked to Wilms tumor in children, and to children of fathers employed as mechanics or welders.

Laryngeal cancer: Metalworking fluids and mineral oils, natural fibres including asbestos, some evidence for wood dust, exposure to reactive chemicals including sulphuric acids. Excesses in rubber workers, nickel refining, mustard gas, chemical production.

Leukemia: Organic solvents and chlorinated solvents, paints and pigments, reactive chemicals, ironising radiation, conflicting evidence on non-ironising radiation, pesticides.

Liver and biliary cancer: Ironising radiation, vinyl chloride and angiosarcoma of the liver, PCBs, some evidence for arsenic, chlorinated solvents and reactive chemicals.

Lung cancer: Arsenic, beryllium, cadmium, chromium, nickel, solvents, particularly aromatics (benzene and toluene), ironising radiation including radon-exposed uranium, hematite and other ore minerals, reactive chemicals including BCME, CCME, mustard gas, plus suggestive evidence for sulpuric acids, passive smoking, petrochemicals and combustion byproducts, asbestos, silica, wood dust, some man-made fibres including ceramic fibres.

Mesothelioma: Asbestos, erionite.

Multiple myeloma: Some evidence for a link to solvents, ironising radiation, pesticides and dye products.

Nasal and nasopharyx cancer: Chromium, nickel, some evidence for benzene, reactive chemicals and formaldehyde, metalworking fluids, natural fibres including wood dust, ironising radiation. Associated with work in footwear manufacturing.

Non-hodgkins lymphoma: Organic solvents, pesticides, PCBs, dioxin and possibly dye products.

Ovarian cancer: Limited evidence for pesticides and ironising radiation. Limited evidence for an excess in hairdressers and beauticians.

Pancreatic cancer:  Acrylamide, metalworking fluid, mineral oils. Some evidence for cadmium, nickel, solvent exposure, reactive chemicals, possibly formaldehyde. Limited evidence for pesticides.

Prostate cancer: Links to cadmium, arsenic and some pesticides. Excess risks have been found for exposure to metallic dusts and metalworking fluids, PAHs and liquid fuel combustion products, and farmers and pesticides applicators.

Rectal cancer: Metalworking fluids and mineral oils. Some evidence for solvents, including toluene and xylene.

Skin cancer:  UV and sun exposure, metalworking fluids and mineral oils. Non-melanoma skin cancers from arsenic, creosote, PAHs, coal tars and ironising radiation.

Soft tissue sarcomas: Vinyl chloride monomer (angiosarcoma of the liver), pesticides. Ewings sarcoma in pesticide exposed workers.

Stomach cancer: Ironising radiation, metalworking fluids and mineral oils, asbestos. Some evidence for solvents and pesticides. Excess risks found in workers from the rubber, coal, iron, lead, zinc and gold mining industries.

Testicular cancer: Evidence for endocrine disrupting chemicals (eg. Phthalates, PCBs and polyhalogenated hydrocarbons). A literature review found significantly elevated risks in men working in industries including agriculture, tanning and mechanical industries and consistent associations with painting, mining, plastics, metalworking and occupational use of hand-held radar.

Thyroid cancer: Ironising radiation.

 

Carcinogenic substances recommendations:

1.      Periodically determine the carcinogenic substances and agents to which occupational exposure shall be prohibited or made the subject of authorisation and control.

2.      Make every effort to replace carcinogenic substances and agents with non-carcinogenic and less harmful alternatives.

3.      Take measures to reduce to the minimum the number of workers exposed to carcinogenic substances, and the duration and degree of exposure and to establish an appropriate recording system.

4.      Ensure that the workers who have been, are, or likely to be exposed to carcinogens, are provided with all the information on the dangers and relevant preventative measures.

5.      Organise medical surveillance or workers at risk, during and after employment.