Hazardous Materials
Hazardous materials, if not stored or handled correctly, can cause harm to workers, members of the public, property and the environment due to their physical, chemical, and biological properties.
Hazardous materials can cause adverse health effects such as asthma, skin rashes, allergic reactions, allergic sensitisation, cancer, and other long term diseases from exposure to substances.
This material focuses on 4 hazardous materials which may be encountered either in the premises of Disability Service Providers or in the work of Australian Disability Enterprises.
Asbestos
Asbestos is the name given to a group of fibrous silicate minerals that occur naturally in the environment. Asbestos was commonly used in a wide variety of industrial, manufacturing, building and construction applications in Australia between the 1940s and late 1980s due to its durability, fire resistance and excellent insulating properties.
The three main types of asbestos are:
- chrysotile (often called white asbestos)
- crocidolite (often called blue asbestos)
- amosite (often called brown asbestos)
Where asbestos is affected by heat or chemicals or combined with other substances its colour and appearance can change. There is no simple test to identify asbestos – an approved laboratory analysis is the only certain method.
Asbestos-containing material (ACM) is any material or object that, as part of its design, contains one or more of the mineral silicates (other than plant in which asbestos is fixed or installed).
ACM can be friable or non-friable.
- Friable ACM when dry may be crumbled, pulverised or reduced to powder by hand pressure. Examples of friable ACM include pipe lagging, boiler insulation, fire retardant material on steel work, sprayed insulation.
- Non-friable ACM is usually bonded or mixed with cement or similar material and cannot be crumbled, pulverised or reduced to powder by hand pressure. Examples of non-friable ACM that can become friable includes asbestos cement sheeting that has been crushed or deteriorated from long-term exposure to a chemical mist.
Generally the presence of asbestos does not pose health risks unless it is broken, in poor or deteriorated condition, or disturbed during activities that produce dust containing asbestos fibres. Inhalation of asbestos fibres is a serious health risk and can lead to diseases such as mesothelioma, lung cancer and asbestosis.
There can be a delay of many years between first exposure to asbestos fibres and any symptoms of these diseases.
A large amount of ACM is still present in the community in both workplace and non-workplaces, including domestic premises constructed or renovated prior to the late 1980s. ACM may be found in asbestos cement roofing, external asbestos cement sheet walls, including brick cladding, internal asbestos cement walls and ceilings, moulded products such as flues, downpipes, guttering, water and sewerage pipes.
ACM may also be found in asbestos felts, ropes, fire blankets and woven asbestos cable sheathing, vinyl floor tiles and sheets, sprayed insulation materials used for fire-proofing, thermal protection, insulation and soundproofing, lagging and other loosely bound insulation materials use din a wide range of electrical thermal and acoustic applications, rubber, plastic and paint products (particularly industrial epoxy paints), sealants, gaskets, adhesives and filters, brake pads and clutch mechanisms and other friction products.
In workplaces where asbestos is fixed or installed, all asbestos must be identified so far as is reasonably practicable. If there is any uncertainty about the presence of asbestos, it must be assumed that it is asbestos or a sample of the suspected material should be analysed for confirmation. Asbestos in workplaces must be clearly identified and, if reasonably practicable, labelled.
An asbestos register must be produced and kept up to date with all relevant information about the identified ACM. The register must include a record of:
- The location of the asbestos
- The type of ACM
- The nature of the ACM (friable or non-friable)
- The condition of the ACM
- The dates of the inspection and details of those who carried out the inspection
- Details of any materials presumed to contain asbestos material
- Any inaccessible areas likely to have ACM
- The results of any analysis that has confirmed (or not confirmed) the presence of asbestos
- The date when the risk assessment was made and details on the competent persons who carried out the assessment
- The findings and conclusions of the risk assessment
- The results of any air monitor or airborne fibres, and the assessment of these results
- The control measures recommended and decided upon as a result of the risk assessment
- Any removal, repair or disturbance of ACM, including the company and persons involved, the date and scope of the work undertaken and details of the clearance certificates.
- Any work activities that may affect or cause damage or deterioration to the ACM.
The register must be accessible to all those within the workplace including contractors and reviewed whenever there is a change to the condition of any asbestos or it is removed, enclosed or sealed or every year.
Asbestos removal work must be performed by an asbestos removal licence holder and/or their employees who are appropriately trained and instructed to perform the removal work safely. Asbestos removal work must comply with strict safety requirements. Some of these are the use of protective clothing and equipment, decontamination facilities, waste disposal procedures, the use of signs and barricades and the preparation of an asbestos control plan.
Lead
Lead is a cumulative poison. When inhaled, ingested or absorbed through the skin, lead is toxic to virtually every human organ.
From a single exposure, lead is quickly distributed and stored through the body where it remains a long term source of internal exposure.
Exposure to lead can have a broad range of health effects depending on the amount of lead present and the length of exposure.
Generally, the greater the exposure, the greater the impact on health, though children will be more affected at lower levels of exposure than adults.
Where lead is stored in the body:
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Who is at risk?
Lead workers are traditionally thought to be those working in mining, smelting and refining industries, or in the manufacture of lead products such as lead-acid batteries. However, there is a large number of occupations outside these industries that either use materials containing lead or can disturb existing lead hazards in older buildings or industrial sites.
Examples of lead-risk occupations
- Abrasive blasters and coaters
- Architects
- Building inspectors
- Cable layers
- Carpenters
- Carpetlayers
- Cabinet makers
- Demolition workers
- Electricians
- Gasfitters
- Glaziers
- Plumbers
- Painters and decorators
- Metalworkers
- Plasterers
- Roofing contractors
- Shopfitters
- Tilers
Occupational exposures in workplaces mostly stem from the inhalation, ingestion and absorption of lead fumes, dusts and particles from a wide variety of sources. Exposure levels can be significantly increased by poor occupational safety and hygiene practices.
Sources of Lead
Lead is described as a 'multi-source toxin'. Workers are particularly at risk as they are often exposed to many sources of lead over long periods of time. Main sources of lead at work are:
- Lead paint including:
- domestic paint used in many houses built before 1970.
- Protective coatings used on industrial buildings, plant and equipment.
- Marine, automotive and vehicle paints.
- Specialised paints, such as road marking and sign writing applications.
- Building products which can contain lead including flashing, sheet lead, PVC products, lead solder and plumbing fittings.
- Petrol and lubricants including leaded petrol, some types of oil and grease and waste oil.
- Hazardous lead dust which can accumulate in old buildings or workplaces which are not cleaned properly. Many work practices commonly used in industry, such as burning, sanding and grinding, can disturb or create hazardous lead fumes and dust which workers can take into their bodies.
There are many other materials and products, often inadequately labelled, commonly used in industry which contain lead.
How lead can enter your body
- Breathing in dust and fumes is the main way lead enters a worker's body. Fine particles of lead can penetrate deep into the lungs and rapidly pass into the blood.
- Eating contaminated food and drinkcan occur if workers don't wash their hands before meals and eat in workplaces where lead dust is present. Smokers can accidentally take in lead dust on their hands or cigarettes.
- Absorption through the skin can occur where leaded petrol or lubricants are handled without gloves or barrier cream. Recent research suggests that fine particles of lead may be able to enter the body through sweat pores in the skin.
Lead and the law
Employers have a duty of care under the NSW Occupational Health and Safety Act 2000 to provide a safe and healthy working environment. Any material containing more than 1% lead is a 'designated hazardous substance' in NSW.
The NSW WorkCover Code of Practice for the Control of Hazardous Substances requires occupational lead hazards to be controlled and specifies the requirements for the labelling, storage, transport and disposal of lead materials and waste.
On a national level, the National Occupational Health and Safety Commission has developed a National Code of Practice for the Control and Safe Use of Inorganic Lead at Work.
How workplaces can control lead hazards
Develop a safe system of work
- Assess lead risks at work. Testing and assessing lead hazards is essential if there is a potential risk from lead. Suppliers and employers are required to provide Materials Safety Data Sheets (MSDS) for any suspect materials or chemicals.
- Use alternatives to lead. Other products are available which are lead free or have less lead eg. acrylic coated flashing, lead free paint and PVC, tin or silver solder etc.
- Create a safe workplace. Many simple changes to plant, machinery, production processes, equipment and work practices can reduce the dangers of lead. Isolating lead hazards or lead processes is critical to reduce risk. Engineering solutions, such as ducted extraction, are highly effective in removing lead dust and fumes.
- Provide facilities and ensure that hands and face are washed before meals and smoking. This will help ensure lead dust is not accidentally ingested. Smoking or carrying cigarettes where lead dust is present is very hazardous. Employers must provide appropriate facilities.
- Ensure that work clothes are changed out of when finished for the day. This stops lead dust being taken home on bodies, clothes and cars and help protect workers' families.
- Ensure the use of appropriate Personal Protective Equipment. Respirators and face masks, overalls, gloves and other PPE will help protect workers from lead and other dangerous materials. Employers are required to provide correct PPE that is properly maintained and to train workers in its proper use.
Mercury
What effect might mercury and compounds have on my health?
The nervous system is very sensitive to all forms of mercury. Exposure to high levels of any types of mercury can permanently damage the brain, kidneys, and developing foetus. Effects on brain functions may result in irritability, shyness, tremors, changes in vision or hearing and memory problems. High exposures of mercury vapour may cause chest pain, shortness of breath, and a build up of fluids in the lungs (pulmonary oedema) that can be fatal. Methyl mercury and mercury metal vapours are especially harmful, because more mercury reaches the brain. Long term exposures may cloud the eye. Contact with mercuric chloride can cause burns to the skin and permanent damage to the eyes. Mercury also accumulates in the body.
How might mercury and compounds enter my body?
Mercury and mercury containing products will enter the body if we breathe in contaminated air, drink contaminated water, eat contaminated food, or have our skin come into contact with it. Mercury may be absorbed through the skin. Mercury released into the environment is converted into methyl mercury by bacteria. The methyl mercury will then build up in the tissues of fish and shellfish. Humans (and other animals) may also be poisoned by eating these fish or shellfish.
How might I be exposed to mercury and compounds?
Mercury can be absorbed through the skin. Workers in the industries that use or produce mercury and its compounds (mercury mines and refineries, chemical manufacturing, dental/health fields, metal smelters) are at risk of exposure. Workers in fossil fuel power plants and in cement manufacturing may be exposed to mercury compounds if they are exposed to gaseous process emissions. Consumers can be exposed to mercury and its compounds by exposure to air from production and processing facilities using mercury and its compounds, by eating fish or shellfish contaminated with methyl mercury. People can also be exposed to mercury from dental work and medical treatments.
What are the mercury health guidelines?
Worksafe Australia:The eight-hour time weighted average (TWA) exposure limit is 0.05mg/m3. Mercury bichloride is also considered to be toxic by inhalation, skin contact, or swallowing.Australian Drinking Water Guidelines (NHMRC and ARMCANZ, 1996):Maximum of 0.001 mg/L (i.e. 0.000001 g/L)
Industry sources
Fossil fuel power plants emit to air, precious metal mining operations may emit to water or land, metal smelters may emit to air, cement manufacture may emit to air. Municipal landfills, sewage, metal refining, and chemical manufacturing are also significant potential emitters of mercury to land and water.
Diffuse sources, and industry sources included in diffuse emissions data
Burning of fossil fuels (home heating oil, petrol) emits to air, disposal of batteries, thermometers and other mercury containing products may emit to land, and photographic processing facilities may emit mercury to water.
Transport sources
The combustion of petrol releases small amounts of mercury to air.
Consumer products which may contain mercury and compounds
Batteries, thermometers, barometers, thermostats, and mercury lights are some of the consumer products that contain mercury. Photographic toners contain mercuric chloride.
Natural sources
Mercury is a naturally occurring element that is found in rocks and ores. Mercury is released into the atmosphere by evaporating from soils, from volcanic activity, and from burning of fossil fuels (coal, oil, petrol, asphalt, etc.).
Precautions for handling mercury
Smoking, eating and drinking are especially hazardous in laboratories where mercury is handled or used. Ideally, clothing and shoes used in such laboratories should not be worn outside the laboratory, since this could spread contamination, particularly into the home. Skin contact should be avoided wherever possible.
Consideration should be given to the more frequent use of fume cupboards, glove boxes, or special enclosures, instead of handling mercury in the open laboratory. Where practical, operations should be carried out over a tray containing water or preferably oil. The oil reduces the release of mercury vapour and helps to prevent the formation of small droplets of mercury. Where mercury is handled frequently, evaluation of vapour concentration should be made at regular intervals using a continuous direct-reading instrument.
The use of exposed mercury should be avoided wherever possible in air-conditioned rooms or areas that generally rely on air recirculation. In such areas the atmospheric contamination can reach dangerous levels. Ideally, exhaust air from areas containing exposed mercury should be vented to atmosphere.
Arsenic
Arsenic compounds, which are designated hazardous substances, are used in agriculture (as an additive to feed), and insecticides, herbicides, larvicides, and pesticides; in pigment production; in the manufacture of glass and enamels, textile printing, tanning, taxidermy, and anti-fouling paints; to control sludge formation in lubricating oils; as an alloying agent to harden lead base bearing materials; with copper to improve its toughness and corrosion resistance; and in a number of laboratory procedures. Arsenic compounds are also used to preserve wood (eg in the treatment of telecommunications poles).
Legal Standards
The NOHSC "Designated List of Hazardous Substances" includes arsenic, arsenic acid and its salts, arsenic compounds and arsine and these substances are therefore regulated under the Victorian Occupational Health and Safety (Hazardous Substances) Regulations. Employers must, by law, implement these regulations, which means they must first try to eliminate the hazard or the risks associated with the hazard. If this is not practicable, then the employer must reduce the risk, according to the preferred order of hazard control - that is by beginning at the source.
Where, after taking all practicable measures to control the risk at the source, there is still a risk that workers may be exposed to arsenic, the employer must provide adequate information, training and where necessary, personal protective equipment.
The training employers must provide should include the following: personal hygiene and sanitation; the use of personal protective equipment; and the early recognition of symptoms of absorption, irritation to the skin, and possible allergic reactions.
Where called for (based on the degree of exposure, the concentration of arsenic, and the national exposure standard), workers should be provided with respirators. Protective clothing, gloves, goggles, and a hood for the head and neck should be provided. Clean work clothes should be supplied daily, and workers should shower prior to changing into street clothes.
Health Effects
Health problems from arsenic exposure occur as a result of inhalation (breathing), absorption (through the skin) or ingestion (swallowing) of arsenic dust and fumes. The common hazards of occupational exposure to arsenic compounds are:
- Irritation of the skin, eyes, mouth, throat and lungs. They can cause skin rashes or dermatitis. The moist mucous membranes of the body are most sensitive to the irritant action. In addition, the skin, eyelids, angles of the ears, nose, mouth, and respiratory membranes are also susceptible to the irritant effects.
- Chronic poisoning, including cancer of the skin and lungs.
- Acute poisoning that may result in death. Acute poisoning by arsenic compounds other than arsine rarely occurs in industry but can occur as a result of inhalation and skin absorption, as well as ingestion.
Cases of severe arsenic poisoning due to inhalation are rare. When it does occur, respiratory tract symptoms - cough, chest pain, difficult breathing, giddiness, headache, and a general weakness of the body - occur. These symptoms may be followed by gastrointestinal or stomach pains.
Chronic arsenic poisoning due to ingestion is also rare. Symptoms are weight loss, nausea, and diarrhoea alternating with constipation, pigmentation, and eruption of the skin, loss of hair, and peripheral neuritis. Horizontal white lines on the fingernails and toenails are commonly seen in arsenic poisoning.
Inhalation of arsenic compounds is the most common cause of arsenic poisoning in the industrial work environment. This condition is divided into three phases:
- The worker complains of weakness, loss of appetite, nausea, occasional vomiting, and some diarrhoea.
- The worker complains of an inflammation of the eyelids and mucous membranes of the nose and respiratory passages. Hoarseness and a cough may also occur. In addition, skin lesions are common.
- The worker complains of pains in the hands and feet. In more severe cases, paralysis may occur.
In addition, it has been proven that arsenic exposure can cause lung cancer. It is also believed that arsenic poisoning may cause liver damage.
Control measures
Where there is a likelihood of worker exposure to arsenic compounds, steps should be taken to
minimise that exposure as far as workable. A thorough examination of work practices is essential.
Procedures should be adopted to ensure that workers are not unnecessarily exposed to the hazard.
Control measures include, but are not limited to, the following, which are ranked in priority of their effectiveness:
- elimination/substitution and process modification;
- engineering controls;
- administrative controls; and
- use of personal protective equipment.
Engineering controls
Care in selection, design, installation, operation and regular maintenance is essential to ensure that the system adequately controls contamination at all times.
The design of an effective ventilation system is a highly specialised area of expertise and therefore should be performed only by those competent to do so. Special care in design is important where combustible, inflammable or potentially explosive materials are involved. Inlets and outlets must not be blocked and must be kept clear at all times.
Air from a local exhaust ventilation system should not be recirculated into the workroom. It should be discharged to the outside air, distant from other work areas, air conditioning inlets or compressors supplying breathing air.
General ventilation systems are not usually as satisfactory in the control of health hazards as is the use of ventilated process enclosures or local exhaust ventilation, but they may be useful to control minor emissions of contaminants of low toxicity. In designing a mechanical ventilation system where such contamination occurs, particular attention should be given to fan selection and to the placement of air extractors and fresh air supply openings. In particular, movement of air should be arranged so that clean air streams are drawn past workers and contaminated ones lead away from them. Such systems require rigorous control over all sources of natural ventilation and air movement which may disturb planned air movement, for example, the operation of air conditioning systems or the opening and closing of doors and windows. Changes or additions to a balanced ventilation system must be implemented in such a way that they will not result in reduced efficiency of the entire ventilation system.
Breathing apparatus should be used only where ventilation or engineering control is impracticable or in non-routine situations.
References
NSW Occupational Health and Safety Act 2000
NSW WorkCover Code of Practice for the Control of Hazardous Substances
Occupational Health and Safety Regulation 2001
Safe Work Australia “Arsenic and Its Compounds” December 1989
