Legal requirements

This section provides a summary of employers' and employees' key responsibilities for ensuring the health, safety and welfare of their employees. Further details can be obtained from publications listed in the reference section.

Employees' health, safety and welfare at work are protected by law. This means that employers have a duty under the law to ensure, so far as is reasonably practicable:

• the health, safety and welfare at work of their employees; and
• employees are consulted and informed about health and safety issues, ie issues are discussed with the employees or their safety representative, if there is one.

Employees have a duty to co-operate with their employer by using the safe systems of work correctly.

Definitions of legal terms

Substances hazardous to health

This term has a legal meaning within the Control of Substances Hazardous to Health (COSHH) Regulations. In summary, it covers:

• substances or preparations carrying the very toxic, toxic, harmful, corrosive or irritant symbol
• substances and products with occupational exposure limits known as workplace exposure limits (WELs)
• biological agents
• dusts of any kind that have a concentration in air equal to or greater than 10 mg/m³ (inhalable) and 4 mg/m³ (respirable)
• substances whose chemical or toxic properties and the way they are used or produced create a risk to health (eg 'wet work').

Suitable and sufficient

The measures taken are appropriate to the risk or risks involved and it is reasonably practicable for prevention or adequate control of the risk or risks involved without increasing the overall risks.

As low as reasonably practicable (ALARP)

This involves weighing a risk against the trouble, time and money needed to control it.

Adequate control

Control measures, including PPE and welfare facilities, can be considered adequate if they can provide a level of protection required to reduce the exposure to comply with the law.

Employers' general duties

In general, the duties of employers include, so far as is reasonably practicable;

• keeping the workplace safe and without risks to health;
• drawing up a health and safety policy statement if there are five or more employees;
• ensuring articles and hazardous substances are moved, stored and used safely;
• providing adequate welfare facilities;
• giving employees the information, instruction, training and supervision necessary for maintaining health and safety;
• appointing a competent person(s) to assist with health and safety responsibilities and consulting employees or their safety representative about this appointment;
• preventing or adequately controlling exposure to hazardous substances that may cause damage to the health of employees and others affected by the undertaking;
• providing free any protective clothing or equipment, where risks are not adequately controlled by other means;
• ensuring that appropriate safety signs are provided and maintained;
• reporting certain injuries, diseases and dangerous occurrences to the appropriate health and safety enforcing authority.

In particular, the employer must:

• assess the risks to employees' health and safety. If there are five or more employees, they must record the significant findings of the assessment;
• identify measures for controlling the risks;
• make arrangements for putting those measures into effect; and
• ensure those measures continue to work and are correctly used.

Employees' duties

Employees have legal duties under the law. They include:

• taking reasonable care for their own health and safety and that of others who may be affected by what they do or don't do;
• co-operating with the employer on health and safety;
• correctly using work items provided by the employer, including personal protective equipment;
• using all safe systems of work in accordance with training or instructions;
• not interfering with or misusing anything provided for their health, safety or welfare.

Control of Substances Hazardous to Health Regulations 2002 (COSHH)

An employer must not carry out any work, which can expose employees, by any route (skin, inhalation or ingestion), to substances hazardous to health, unless the employer has:

• carried out a 'suitable and sufficient' risk assessment of the health risks created by that work; and
• identified the steps needed to comply with the regulations; and
• put the identified steps into effect.

Working with substances hazardous to health: A brief guide to COSHH

Prevention or control of exposure

The risk assessment must consider whether it is reasonably practicable to prevent skin exposure. If prevention is not reasonably practicable, the assessment should identify how to ensure adequate control of skin exposure. The COSHH Regulations are 'goal setting' and recognise that risk cannot always be eliminated. The aim is therefore to reduce the risk of exposure.

Skin exposure risk assessment

A risk assessment should take account of the following:

• hazardous properties of the chemical(s);
• health effects caused by the chemical(s);
• routes, extent, frequency and duration of exposure;  
• amount of chemical(s) used or produced, including those produced as by-products, released by chemical reactions during the process or found in waste products;
• type of work (such as emergency, maintenance or routine work);
• where it is carried out (eg fixed installation, temporary site or peripatetic work);
• effectiveness of controls. Those identified during the risk assessment or existing preventive or control measures;
• results of any monitoring data (eg surface contamination, skin contamination and biological monitoring);
• results of applicable health surveillance data.

Recording a risk assessment

Where there are five or more employees, the employer must record the findings of:

• the risk assessment; and
• the preventive or control steps to be put in place, including administrative measures, to comply with the regulations.

Reviewing a risk assessment

The employer must review the assessment if:

• for any reason, the assessment is considered to be not valid; or
• the work has changed; or
• some other information has become available and indicates that the assessment is no longer valid.

More advice on risk assessment.

COSHH hierarchy of control

Regulation 7 of COSHH states that an employer's overriding duty is to prevent employees being exposed to substances hazardous to health. Where this is not reasonably practical, employers must achieve adequate control of exposure. To achieve adequate control the hierarchy listed below in order of priority, must be applied. Most work situations will require several levels of the hierarchy to be used to adequately control the risks associated with skin exposure.

• Design and use appropriate work processes, systems and engineering controls and use suitable work equipment and materials.
• Control the exposure of the substance at source (eg enclosures, adequate exhaust ventilation systems and appropriate organisational measures).
• Where adequate control cannot be achieved by other means, provide adequate protective equipment (such as suitable chemical protective gloves).

Adequate control of dermal exposure

Where it is not reasonably practicable to prevent dermal exposure to chemicals, the employer must consider and apply, as appropriate for the circumstances of the work, the 'principles of good control practice'. To achieve adequate control of skin exposure this includes all of the following:

• design and operate processes and activities to minimise emission, release and spread of substances hazardous to health;
• take account of all relevant routes of exposure (skin, ingestion and inhalation) when developing control measures;
• control exposure by measures that are proportionate to the health risk;
• choose the most effective and reliable control options, taking into account ergonomics and ease of use;
• provide suitable PPE where adequate control cannot be achieved by other means;
• check and review of all control measures for their continued effectiveness;
• inform or train employees on the hazards, risks and use of controls measures;
• ensure control measures introduced do not increase overall risks to health and safety.

COSHH requires employers to monitor the effectiveness of their controls and in some situations to carry out monitoring and/or health surveillance.

Dermal exposure monitoring

Before carrying out a dermal exposure monitoring exercise, it is important to establish a clear purpose, and to work out how you will assess the significance of the results and what you will do with them.

• Dermal exposure monitoring should provide a demonstration that engineering and procedural controls are adequately controlling the exposure.
• The results should be able to highlight where controls are not adequate, and target the areas where improved controls are required, or they should help to confirm that further control measures are not required.
• If there are changes to processes, or work procedures, monitoring can be used to assess whether or not employee exposure has changed as a result of the changes.

The decision to carry out dermal exposure monitoring should be informed by:

• the COSHH assessment;
• whether control failure could result in a serious health effect (eg skin sensitisation or cancer);
• whether a suitable procedure exists or can be devised.

Health surveillance

As part of the risk assessment employers should also find out whether health surveillance is required. Health surveillance is for the protection of individuals, to identify as early as possible any indications of disease or adverse changes related to exposure, so that steps can be taken to treat their condition and to advise them about the future. It may also provide early warning of lapses in control and indicate the need for a reassessment of the risk.

Because predictive tests are never likely to be totally reliable, and because certain known toxic agents still need to be used, dermatological health surveillance must never be regarded as reducing the need for control of exposure and effective decontamination after exposure.

More detailed information can be found on our health surveillance for skin diseases page.

Competent persons

Regulation 12 of COSHH requires that people carrying out assessment, evaluation, monitoring, health surveillance and advising on control of risks arising from exposure to substances hazardous to health should have adequate knowledge.

If an employer delegates the work, the person or people that the work is delegated to should have adequate knowledge. If this work is delegated to an employee, then suitable training to gain the knowledge is necessary.