Identifying and Assessing Hazardous Substances: Best Practices

There are thousands of hazardous substances in daily use in workplaces that workers, others and the environment may be exposed to, and many materials or substances used or created at work can be harmful to health. Every year, exposure to hazardous substances at work affects the health and wellbeing of many thousands of people, and also can have a financial impact on the individual, the business and the wider economy. The high costs of ill health and/or injury arise from loss of earnings, loss of productivity, prosecution and civil action, amongst others, so it is critically important that these hazards are identified, assessed and mitigated in order to minimise the probability of an accident, injury or any other form of harm occurring. 

Having effective risk assessment and control measures in place for hazardous substances in the workplace helps organisations to both promote employee safety and ensure compliance with regulations. In this article we will examine the best practices for identifying and assessing hazardous substances in the workplace.

Understanding Hazardous Substances

The Health and Safety Executive (HSE) defines a hazard as “anything that may cause harm”. Substances that are hazardous to health can take a variety of different forms. These substances include but may not be limited to:

• Biological agents including bacteria, viruses, fungi, other microorganisms and their associated toxins
• Chemicals such as bleach, acid, solvents or adhesives
• Dust such as crystalline silica dust, wood dust, asbestos dust, metal dust, coal dust, flour
• Fumes or mists such as welding or soldering fumes, paint fumes, benzene, acetone
• Gases and asphyxiating gases including carbon monoxide, hydrogen sulphide, carbon dioxide, chlorine, ammonia, hydrogen chloride, fluorine and sulphur dioxide
• Germs that cause diseases, microorganisms such as bacteria and viruses commonly known as pathogens
• Nanotechnology such as ultra-fine powders and coatings
• Products containing chemicals such as drugs, cosmetics, cleaning chemicals, degreasers, detergents etc.
• Vapours such as solvent vapour released from adhesives, paints or inks, dust, powder or paste

As you can see above, hazardous substances include the most dangerous chemicals, waste products, germs and other biological materials, incredibly small nanoparticles, and dusts, all of which can be harmful. These substances may harm if they are inhaled, swallowed, or if they touch the skin. 

Depending on the hazardous substance, the effects can be short term and treatable with the right medical care, or they can be serious or even fatal. Some hazardous substances produce immediate effects upon exposure such as irritated eyes or skin rashes. Corrosive substances can cause extensive damage immediately upon contact with the skin or eyes.

Some forms of dust such as fibreglass dust can cause immediate or ‘acute’ health issues. It can cause breathing problems when inhaled, can irritate the eyes and cause skin rashes on contact. Another form of dust, asbestos, is one of the strongest examples of a substance that doesn’t always cause immediate physical harm to a person, but can have serious damaging effects on them many years after exposure. Mesothelioma, asbestos-related lung cancer, asbestosis and pleural thickening are all caused by inhaling asbestos fibres.

Other health risks and injuries that can be caused by exposure to hazardous substances include, but are not limited to:

• Allergy – some hazardous substances may cause hypersensitivity, known as an allergy, of the immune system. First, the immune system acquires hypersensitivity as a result of exposure to the allergen. At each subsequent contact with the same substance an abnormally strong immune response occurs, which may result in allergic disease such as allergic contact dermatitis or eczema, or allergic asthma. Occupational allergens are those allergens to which exposure at work may occur such as, but not limited to, flour dust, animal skin or rubber latex, preserving agents in cosmetics, paints, adhesives etc.
• Rhinitis – this is an inflammation of the nose, which may be caused by irritants or allergens. Rhinitis often precedes the development of allergic asthma.
• Asthma – asthma is a serious disease that may be life-threatening, and can be caused or exacerbated as a result of developing an allergy to substances used at work.
• Dermatitis – this is an itchy inflammation of the skin caused by direct skin contact with substances such as chemicals used in, for example, hairdressing.
• Viral infection – this is caused by bacteria and other microorganisms such as biological agents.
• Chemical burns – harmful acids and chemicals include bleach, ammonia, and chemicals used in industries such as farming, manufacturing, construction and laboratories.
• Lung inflammation – this can be caused by inhaling chemicals such as chlorine gas, pesticides, gasoline, smoke and nanoparticles found in the manufacture of, for example, scratchproof eyeglasses, crack-resistant paints, anti-graffiti coatings for walls etc.

Dangerous substances are flammable gases, mists or vapours, or combustible dusts. They are substances used or stored at work that could, if not properly controlled, cause fire and/or explosive atmospheres. The effects of an explosion or a fire in the workplace can be devastating in terms of lives lost, injuries, significant damage to property and the environment, and to the business community. Examples of dangerous hazardous substances found in the workplace might include:

• Solvents
• Paints and varnishes
• Flammable gases
• Welding gases
• Liquid petroleum gas (LPG)
• Pressurised gases
• Methane gas
• Dusts from machining and sanding operations
• Dusts from foodstuffs
• Substances corrosive to metal
• Liquids such as petrol and other fuels, and solvents in industrial products such as paint, ink, adhesives and cleaning fluids, give off flammable vapour which, when mixed with air, can ignite or explode.
• Uncontrolled releases of gases, such as liquefied petroleum gas (LPG), hydrogen or other flammable industrial gases and methane, can readily ignite, or cause the cylinder to become a missile. The flammable gases and oxygen used as a fuel for hot work and flame cutting can give rise to fire and explosion risks on their own without any involvement of any other dangerous or combustible substances.
• Dusts which can form explosive atmospheres are also classed as dangerous substances. They can be produced from many everyday materials such as coal, wood, flour, grain, sugar, certain metals and synthetic organic chemicals.
• Many chemical substances can be a fire or explosion risk as they can give rise to harmful heat and pressure effects because they are unstable or because they can react violently with other materials.
• Solids include materials such as plastic foam, packaging, and textiles which can burn fiercely and give off dense black smoke, sometimes poisonous.

Environmental hazards are substances or practices that pose a risk to an ecosystem and environment. Substances are classed as hazardous if they are harmful to either human health or the environment, with many hazardous substances posing a threat to both. For example, chemical discharges can contaminate and degrade the environment, impacting ecosystems adversely, and negatively impacting the condition of air, water and soil, and the health of wildlife and humans. They can also contribute to wildlife population declines. Hazardous substances can degrade or destroy natural habitats, making them uninhabitable for certain species and reducing biodiversity. 

Soil contamination can be caused when hazardous substances such as industrial chemicals, pesticides and heavy metals accumulate in the soil. The effect can be a reduction in the variety of microorganisms, plants and animals that live in the soil, disrupting ecosystems. The contamination can reduce soil fertility, harm plants, and pose risks to animals and humans throughout the food chain.

Hazardous substances such as industrial chemicals, solvents, pesticides, fertilisers, sewage and heavy metals such as lead, can pollute seas, rivers, lakes and groundwater. This can lead to the death of aquatic life, contamination of the food chain, disruption of ecosystems, and can make water unsafe for human consumption.

Air pollution by hazardous substances can cause both short-term and long-term effects on health and can contribute to smog and acid rain formation. Acid rain can damage ecosystems, soil and water. Some hazardous substances such as industrial gases and CFCs can deplete the ozone layer and contribute to global warming. 

All of the above also negatively impact the economy, as agriculture farming and fishery productivity can be affected, human ill health places a strain on the NHS, and costs for cleaning up contaminated sites and restoring ecosystems are often borne by taxpayers. 

Mitigating and managing the risks posed by hazardous substances is crucial for minimising the potential of health risks, accidents, injuries and damage to humans, wildlife and the environment.

Regulatory Framework

The Health and Safety at Work etc Act 1974 is the primary piece of legislation governing workplace health and safety in Great Britain. The Act defines the general duties of everyone from employers (section 2) and employees (section 7 and 8) to owners, managers and maintainers of work premises (etc) for maintaining health and safety within most workplaces. All UK employers have a legal duty of care for the health and safety of their employees. This means they must provide a safe place of work and make sure their workplace complies with the Health and Safety at Work etc. Act 1974 (HASAWA), the Workplace (Health, Safety and Welfare) Regulations 1992, and the Control of Substances Hazardous to Health (COSHH) Regulations 2002.

Under the COSHH Regulations, employers and workplaces must provide information, training and equipment to mitigate risk and injury, and employees must ensure they follow protocols. 

Employers have a number of key responsibilities regarding COSHH laws. These include:

• Exposure – employers must prevent or control exposure to hazardous substances. This can include the provision of appropriate personal protective equipment (PPE) where necessary.
• Control measures – implement control measures around hazardous substances and ensure these are maintained and kept up to date, in full working order and clean where appropriate.
• Instruction – provide employees with information, instruction and training about working with hazardous substances.
• Procedures – have procedures in place to deal with accidents and emergencies relating to hazardous substances.
• Surveillance – ensure employees exposed to hazardous substances are under adequate surveillance.
• Risk assessments – carry out COSHH risk assessments.
• Limits – ensure the use of hazardous substances doesn’t exceed the Workplace Exposure Limit (WEL).
• Supervision – check employees are carrying out tasks as they are supposed to.

Employees have the responsibility to ensure that tasks are carried out safely to ensure no harm comes to themselves or others. These include:

• Safety – assist their fellow employees in creating a safe working environment. This can include supporting colleagues to abide by the regulations specific to their workplace.
• Procedures – follow the procedures put in place to stop accidents and overexposure.
• Personal protective equipment (PPE) – wear the correct PPE including eye and noise protection. This includes ensuring all PPE is stored correctly in the appropriate place.
• Reporting – report and record all accidents, spillages and breakages.
• Check-ups – attend medical check-ups when required to.
• Cleaning – use cleaning and showering facilities provided by employers in line with official procedures.
• Training – keep up to date with training provided by employers.

The Management of Health and Safety at Work Regulations require that an employer must suitably assess work-based activities and implement any appropriate controls to manage potential risks to the health, safety and welfare of employees (and others).

The Health and Safety Executive (HSE) is the government appointed body that is responsible for enforcing workplace health and safety legislation in the UK. However, when it comes to enacting enforcement, this responsibility is generally divided between the HSE and relevant local authorities.

No one has to have been harmed for an offence to be committed under HASAWA, there only has to be a risk of harm. It is the responsibility of the employer to ensure that they are managing and controlling risk in the workplace.

The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002 places duties on employers to protect people from risks to their safety from fires, explosions and similar incidents arising from dangerous substances. The legislation requires risk assessments and appropriate safety measures for handling and storing hazardous substances.

The Environmental Protection Act 1990 and the Environment Act 1995 define structure and authority for waste management and control of emissions into the environment. 

The Water Resources Act 1991 regulates water resources, water quality and pollution, and flood defence.

The Planning (Hazardous Substances) Act 1990 and the Planning (Hazardous Substances) Regulations 2015 explain planning controls relating to storing or using hazardous substances at or above defined limits at a site.

The Hazardous Waste (England and Wales) Regulations 2005 govern the production, collection and disposal of hazardous waste to ensure safe handling and prevent environmental contamination.

The Classification, Labelling and Packaging of Chemicals (Amendments to Secondary Legislation) Regulations 2015 ensures that the hazards presented by chemicals are clearly communicated to workers and consumers through standard symbols and phrases on packaging.

Risk Assessment Process

A Control of Substances Hazardous to Health (COSHH) Risk Assessment must be carried out by someone considered ‘competent’. This could be a safety manager, supervisor or other competent person designated by the employer. There is no specific training designated by the Health and Safety Executive (HSE), but the person nominated must have the necessary knowledge, training and experience to identify and assess the risks posed by hazardous substances in the workplace. Many third-party companies can be hired to complete a COSHH Risk Assessment, but there is no legal obligation to use a third party.

Step 1 – what is the hazard and who may be harmed?

The employer must identify the hazard and consider who may be harmed, by collecting information on all the hazardous substances, including waste and by-products, and any used by another employer nearby. If the workplace is shared, the employers must share information and work together to prevent harm. Safety data sheets provided by suppliers of dangerous chemicals, the labels on products, industry standards, and guidance from unions and the Health and Safety Executive (HSE) may provide this information.

Next, the employer must consider how likely and seriously someone may be harmed. Questions they should ask include:

• How much of the substance is there and in what form?
• What type, how long, and how much exposure, if any, is there?
• Does anything indicate that employees are being harmed (e.g. the results from health checks or other measurements)?
• Who may be exposed, particularly the vulnerable, such as pregnant women, young or inexperienced workers, and people with disabilities or pre-existing conditions, including asthma and dermatitis?

Step 2 – prevent or minimise exposure

If there is a significant chance of harm, then the employer must prevent employees’ exposure if reasonably possible. Can they:

• Do the work in a different way so that the dangerous substance is not needed or produced, or exposure becomes impossible?
• Use a safer alternative, e.g. pellets instead of powder which release less dust?

But before making a change, the employer must check that it really is safer and that any new hazards are also risk assessed. If prevention is not possible, then the employer must minimise/control exposure by:

• Considering all types of exposure and using the smallest amount of substance possible
• Limiting the number of employees exposed, and their length and level of exposure
• Controlling exposure early in the process using the most effective and reliable methods
• Not breaking workplace exposure limits (WELs)
• Providing personal protective equipment (PPE) in addition to, and not in place of, other control measures
• Regularly reviewing and checking control measures and not creating new uncontrolled or more significant hazards
• Giving employees information and training on how and why to use the control measures.

Further specific control measures are required if a substance may cause cancer or genetic damage, or where the work is with harmful biological material including germs and cells, for example, refuse disposal, or work with bedding or laundry. Separate requirements also cover sharps use in healthcare. The employer must clean, check, test and maintain physical control measures. Safe systems of work, procedures and supervision must also be checked. Defects should be put right as soon as possible, or immediately if serious, and if a serious exposure is a risk, the work may need to stop.

Any PPE must be provided to employees for free, followed by training and supervision on its correct use. Employees and union reps should have been asked about its selection so that employees find it comfortable and practical. It must be properly stored, maintained, and replaced or repaired when defective. If possibly contaminated, employees must remove PPE when leaving the work area and keep it separate from uncontaminated clothing and equipment.

Workers should quickly remove any accidental contamination and wash any affected parts of their body. It may be appropriate to use skin creams before beginning the work. If exposure by mouth (i.e. ingestion) is a risk, workers must not eat, drink or smoke before removing any contaminated clothing in the place specific for this, and thoroughly washing their hands and face, and under their fingernails. If necessary, there should be suitable uncontaminated facilities for washing, changing, eating and drinking.

Step 3 – record the details

Employers with five or more employees must record, on paper or electronically, the significant findings, which are:

• The hazards and risks
• Who may be harmed and how
• The measures of prevention or control
• Who is responsible for making sure that those measures are taken

But it is best practice for all employers, irrespective of size, to do this to prove that they have carried out a risk assessment and for the future as a reminder, checklist, and during a review. The employer must tell workers and their safety rep about the findings.

Step 4 – review and update

In workplaces, things change, so the employer must review their risk assessments:

• At least once a year and possibly more often depending on the hazard and the chance and seriousness of any harm.
• If there’s a significant change, such as new or different equipment, substances, or information that indicates that the assessment is out of date, e.g. the results of a check, some harm occurring, a near miss or other incident.

Other changes might include recruitment of new workers, developments in technology, or changes to the cost of safer alternatives which might mean that the employer could now improve upon the current measures of prevention or control. Even if the current ones are to remain in place, they must be checked to see whether they are working as expected or need improving.

Step 5 – checks, plans and procedures

The employer must measure the amount of hazardous substances that their employees are exposed to if this is necessary to protect them from serious harm, to ensure that exposure limits are not exceeded or where control measures might fail. If employees are exposed, the employer must also pay for health surveillance where it is appropriate, low risk, and reasonably possible to detect any likely harm. This should take place in a suitable private room, during work time, and with a suitably trained employee or medical expert, as appropriate. Employees and union reps should have been consulted on the procedure to ensure that it is acceptable, and informed about any symptoms or signs to look out for. Employees must attend health surveillance if offered, but any negative results must not be used to discriminate against them if they find them less fit or more susceptible. If something of concern is found, the employee must be informed by a suitably qualified person and be provided with appropriate information and advice. The employer will have to consult the employee and if applicable with their union rep if they wish, if it is necessary for their health to find them alternative work.

If there is a risk of an accident, incident or emergency, the employer must have a plan if the exposure and risk of harm may be way above the normal daily risks, for example:

• The substance may cause cancer, damage the genes, or is a biological or sensitising substance to which the body may over-react
• A serious spill or flood of corrosive agents that is likely to make contact with the skin
• A serious failure of controls that could lead to a sudden release, or a significant exposure over a workplace exposure limit (WEL)

The intention is that the plan will enable an immediate response by following set emergency procedures, and indicate how to warn and advise other workers and the emergency services, etc. The plan must be regularly practised as safety drills, and reviewed and updated. Appropriate first aid facilities must also be provided. The safety data sheet for a particular substance will contain information on how to deal with it during an incident, etc.

Step 6 – inform and consult

The employer must give employees and their safety rep, suitable and sufficient information, instruction, training and supervision about controlling exposure. This includes:

• Details about the hazardous substances
• The findings from the risk assessments
• The measures of prevention and control
• PPE and hygiene facilities
• Any checks, emergency plans or procedures

Employees and safety reps must be consulted by their employer. Employees play a key role in checking the assessments because they know how the job is done and whether the suggested measures are practical. They may identify hazards, risks, ineffective safety measures, or solutions that those less familiar with the work may miss. Research shows that health and safety measures are more effective when the workers and their safety reps are involved.

Best Practices for Identification

Under COSHH legislation, a business is legally required to keep records of all of the chemicals stored in the workplace, both indoors and outdoors, so it is important to ensure that businesses maintain complete, up-to-date records of the chemicals and other hazardous substances stored on site. A major part of the work that goes into keeping workers safe is constantly tracking which substances are used in the workplace.

A chemical inventory is basically a list of all the hazardous substances currently held on-site, what they are being used for, where they are stored, how much is stored, when they were last assessed and when a new assessment is due to be made.

It is best practice to keep the inventory as simple as possible, easily accessible and up to date. If the inventory is easy to access and navigate, it ensures that anyone looking at it is able to find the information they need as quickly as possible, and to know that the information is current and accurate.

Each and every one of the hazardous substances present in the workplace should have a chemical safety data sheet which is provided by the supplier. By law, such as REACH, suppliers of chemicals must provide an up-to-date safety data sheet if a substance is dangerous for supply. Safety data sheets provide information on chemical products that help users of those chemicals to make a risk assessment. They describe the hazards the chemical presents, and give information on handling, storage and emergency measures in case of an accident. Safety data sheets should be used to inform the risk assessments.

Employees who work directly with chemicals should be regularly surveyed to gather insights on potential hazards that may not be documented or obvious. Additionally, employers should ensure that all containers of hazardous substances are properly labelled according to the Classification, Labelling and Packaging (CLP) Regulation 2009, and if in any doubt, contact the supplier.

Assessing Exposure and Risks

Once the chemical hazards have been identified the next stage is to assess what the potential exposure is to employees. This involves looking at each chemical identified as hazardous and considering the following questions:

• How is the chemical used, e.g. sprayed, poured, and how often is the chemical used?
• How will the user be exposed? For example, breathing it in, contact with skin etc.?
• How much is used/generated?
• How long is each user exposed to the chemical, e.g. full shift or a few minutes?
• Who uses the chemical, e.g. how many people?
• Are any vulnerable groups potentially exposed, e.g. are there any chemicals in use that can damage the reproductive process?
• Is the chemical mixed with other chemicals or exposed to high temperatures or pressure?
• Can non-users be exposed, e.g. people working nearby, visitors, cleaning or maintenance staff?

Monitoring exposure to hazardous substances will sometimes be necessary in the workplace. This may be to ensure that employees are not unnecessarily exposed to chemicals, in response to complaints from employees, to check the efficiency of controls or to ensure that a workplace exposure limit (WEL) has not been exceeded. Monitoring can also indicate the spread of contamination.

Direct-reading instruments are valuable tools for detecting and measuring worker exposure to gases, vapours, aerosols and fine particulates suspended in air. Commonly used direct-reading instruments include battery-powered gas chromatographs, organic vapour analysers and infra-red spectrophotometers. Biological monitoring measures how much of a substance has entered the body.

Control Measures

Control measures must be put in place in order to keep employees, the workplace and the environment safe. The first consideration should be to eliminate the hazard by changing the process or removing the hazardous chemical. If the chemical(s) cannot be eliminated, can it be substituted with another, non-hazardous or less hazardous chemical? Where this is not possible, exposure to hazardous substances should be minimised and additional control measures must be put in place to remove or reduce the risks to employees. These might include, for example:

• Engineering controls such as local exhaust ventilation (LEV), on-tool extraction, isolation/containment hoods or booths.
• A systematic review of current work practices or procedures to reduce the frequency and length of exposure to hazardous substances.
• Specific storage arrangements so that hazardous substances are stored correctly, safely and securely.
• Personal protective equipment (PPE), e.g. eye protection, gloves, masks and respiratory masks (RPE). The risk assessment should specify the exact glove type, filter type etc. PPE should be used to control any residual risk in addition to taking all the other measures, not in place of, as PPE only protects the user.
• The implementation of a robust system for reporting and investigating any accidents or near misses involving hazardous substances.

Training and Awareness

Training for employees on the chemicals currently used in the workplace, what the chemical hazards are and the potential risks to their health, and how to handle chemicals safely is imperative to mitigate risks. It is crucial that employees understand the outcome of risk assessments and what this means for them. They should also know what to do if there is an accident, for example a spillage or other emergency, and have access to safety data sheets and the meaning of CPL symbols. When employees are equipped with this knowledge it helps to promote a culture of safety and safe working.

Training and awareness need to be updated whenever there are changes to substances or processes used and reviewed on a regular basis to ensure compliance. Employers should keep records of training undertaken, when and by who. If an accident occurs, investigators will require these records.

Monitoring and Review

As no workplace remains static, every part of the risk assessment process, including training, needs to be regularly monitored and reviewed. Any changes such as changes in work patterns, new employees, machinery, equipment or materials will mean that the risk assessment needs to be reviewed and updated where necessary. 

A programme of regular, preventive maintenance keeps control measures in optimum condition, for example inspecting and testing engineering controls and PPE, and spot-checking procedures and employees’ work practices. 

Businesses should also conduct regular audits of substances and processes to ensure ongoing compliance with regulations and best practices. Regulatory bodies such as the HSE and the Environment Agency provide updates about new or changing regulations regarding hazardous substances. 

Case Study

Cleaners working for an employer in the north-west were using a whole range of cleaning products from different manufacturers. The products were not labelled, so the cleaners did not know when and where they should and should not use each one, or what safety precautions they needed to take.

Using unlabelled chemicals is extremely dangerous. Some must be diluted to a particular strength for safe use. Others must never be mixed, such as acids in some cleaning agents, and bleach which is an alkaline, for risk of a dangerous reaction. Some cleaners had noticed that certain substances they were using irritated their skin, others smelled strange and caused headaches.

The union safety rep held a meeting with the cleaners to get their views and then carried out their own inspection. The rep reported all the risks that they found, in writing, to management. They also asked them for their COSHH risk assessments and for a meeting to discuss the problem. It transpired that no formal COSHH assessments had been carried out. It was then agreed that management would obtain all the manufacturers’ safety data sheets for each substance used, as a first step towards conducting the assessments.

The union reached agreement with the employer that only three main cleaning substances would be used. These would be kept in different coloured and labelled containers and the cleaners were to be given training in their safe use.

Conclusion

COSHH is a crucial component in ensuring the health and safety of all workers who use, handle or store hazardous substances in their place of work. Without this important piece of legislation, rules would not be as heavily enforced concerning hazardous substances in the workplace and there would likely be many more workplace accidents and injuries associated with the use of these materials in the UK.

In this article we have highlighted many of the hazardous substances that can be found in UK workplaces and revealed the potential harm that can be done not only to humans but also to wildlife and to the environment if the risks that these hazardous substances pose are not controlled. We have discussed the steps that should be taken to complete COSHH risk assessments. Completing these is the employer’s responsibility. However, employees also have a responsibility to comply with the findings and recommendations of the COSHH risk assessment, not only to ensure their own safety and wellbeing but also that of others.