Everyone at work has a legal right to be protected from workplace-related risks. Legislation is written to ultimately protect workers and keep people safe at work. The law also gives the Health and Safety Executive (HSE) and Local Authority inspectors the authority to issue notices, halt dangerous work, prosecution, fines and even imprisonment.

These are illustrated as broad general duties for employers, the self-employed and employees using the Health and Safety at Work Act 1974. Subsidiary regulations such as those dealing with the management of health and safety, confined space, and specific health and safety management issues provide more detail.

While most modern health and safety law applies ‘across-the-board’, there are also additional regulations covering industry sectors such as construction, agriculture, railways, mines and quarries and major hazard and nuclear installations.

Health and Safety at Work Act 1974

In the United Kingdom, under domestic law (the Health and Safety at Work Act 1974) employers are responsible for ensuring the safety of their employees and others. This responsibility is reinforced by regulations such as:

Confined Space Regulations 1997

By order of the HSE, the Confined Spaces Regulation 1997, calls for a safe system of work, when working in confined spaces is unavoidable.

What is the definition of a ‘confined space’?

A confined space is a place that is substantially (but not always entirely) enclosed and where there is a risk of death or serious injury from hazardous substances (e.g. lack of oxygen).

Very often, injuries and deaths occur as a result of work being carried out such as welding, painting, flame-cutting, use of chemicals.

Places can also become confined spaces during construction work, fabrication or modification.

Examples include:

poorly ventilated rooms

What are the risks of working in confined spaces?

Every year, a number of people are killed and others seriously injured working in confined spaces across a wide range of industries in the UK, from those involving complex plant to simple storage vessels.

Those killed include not only people working in confined spaces but those who try to rescue them without proper training and equipment.

Dangers can arise in confined spaces because of:

lack of oxygen
poisonous gas, fume or vapour
liquids and solids suddenly filling the confined space, or releasing gases into it when disturbed
explosions and fire
residues left behind which can give off gas, fume or vapour
hot working conditions

The Management of Health and Safety at Work Regulations, 1999

These Regulations (usually called the Management Regulations) generally make more explicit what employers are required to do to manage health and safety under the Health and Safety at Work Act.

Like the Act, they apply to every work activity. Please note that failure to comply with these regulations is a criminal offence.

They set out how health and safety should be managed in workplaces, with the emphasis on risk assessment.

These regulations require that a suitable and sufficient assessment of the risks for all work activities is carried out for the purpose of deciding what measures are necessary for safety.

For work in confined spaces, this means identifying the hazards present, assessing the risks and determining what precautions to take.

In most cases the assessment will include consideration of:

the task
the working environment
working materials and tools
the suitability of those carrying out the task
arrangements for emergency rescue

You may need to appoint competent people to help manage the risks and ensure that employees are adequately trained and instructed.

You may be the best person to do this, or you may need to train someone else to manage risks or engage the services of a competent person for additional help.

If your assessment identifies risks of serious injury from work in confined spaces, such as the dangers highlighted above, the Confined Spaces Regulations 1997 apply.

Control of Substances Hazardous to Health Regulations 2002

What is Control of Substances Hazardous to Health (COSHH)?

The occupational use of nanomaterials is regulated under the COSHH is the law that requires employers to control substances that are hazardous to health. You can prevent or reduce workers’ exposure to hazardous substances by:

finding out what the health hazards are;
deciding how to prevent harm to health (risk assessment);
providing control measures to reduce harm to health;
making sure they are used;
keeping all control measures in good working order;
providing information, instruction and training for employees and others;
providing monitoring and health surveillance in appropriate cases;
planning for emergencies.

Most businesses use substances, or products that are mixtures of substances. Some processes create substances. These could cause harm to employees, contractors and other people.

Sometimes substances are easily recognised as harmful. As a new technology, the risks of exposure associated with nanomaterials are not currently fully understood. Whilst knowledge gaps exist, HSE recommends a precautionary approach to risk management with control strategies aiming to reduce exposure as much as possible.

Dust is considered to be a substance hazardous to health under COSHH if it is present at a concentration in air equal or greater than 10mg/m3 (for inhalable dust) or 4mg/m3 (for respirable dust) as a substance hazardous to health.

COSHH covers substances that are hazardous to health. Substances can take many forms and include:

products containing chemicals
gases and asphyxiating gases
biological agents (germs). If the packaging has any of the hazard symbols then it is classed as a hazardous substance
germs that cause diseases such as leptospirosis or legionnaires disease and germs used in laboratories.


COSHH 2002 imposes requirements by reference to the EH40 guidelines of workplace exposure limits (WELs). These are legally binding as they’ve been approved by the Health and Safety Executive.

These Regulations require employers to prevent or control exposure to hazardous substances. The absence of a substance from the list of WELs does not indicate that it is safe. For these substances, exposure should be controlled to a level to which nearly all the working population could be exposed, day after day at work, without any adverse effects on health.

Personal Protective Equipment at Work Regulations 1992

Why is Personal Protective Equipment (PPE) important?

Making the workplace safe includes providing instructions, procedures, training and supervision to encourage people to work safely and responsibly.

Even where engineering controls and safe systems of work have been applied, some hazards might remain. These include injuries to:

the lungs, e.g. from breathing in contaminated air
the head and feet, e.g. from falling materials
the eyes, e.g. from flying particles or splashes of corrosive liquids
the skin, e.g. from contact with corrosive materials
the body, e.g. from extremes of heat or cold
PPE is needed in these cases to reduce the risk.

What do I have to do?

PPE is the last line of defence and should be used as a last resort.
If PPE is still needed after implementing other controls (and there will be circumstances when it is, e.g. head protection on most construction sites), you must provide this for your employees free of charge
You must choose the equipment carefully (see selection details below) and ensure employees are trained to use it properly and know how to detect and report any faults

PPE Selection and use

You should ask yourself the following questions:

Who is exposed and to what?
How long are they exposed for?
How much are they exposed to?

When selecting and using PPE:

Choose products which are CE marked in accordance with the Personal Protective Equipment Regulations 2002 – suppliers can advise you
Choose equipment that suits the user – consider the size, fit and weight of the PPE. If the users help choose it, they will be more likely to use it
If more than one item of PPE is worn at the same time, make sure they can be used together, e.g. wearing safety glasses may disturb the seal of a respirator, causing air leaks
Instruct and train people how to use it, e.g. train people to remove gloves without contaminating their skin. Tell them why it is needed, when to use it and what its limitations are

Other advice on PPE

Never allow exemptions from wearing PPE for those jobs that ‘only take a few minutes
Check with your supplier on what PPE is appropriate – explain the job to them
If in doubt, seek further advice from a specialist adviser

The Dangerous Substances and Explosive Atmospheres Regulations 2002

What is DSEAR?

DSEAR stands for the Dangerous Substances and Explosive Atmospheres Regulations 2002.

Dangerous substances can put peoples’ safety at risk from fire, explosion and corrosion of metal. DSEAR puts duties on employers and the self-employed to protect people from these risks to their safety in the workplace, and to members of the public who may be put at risk by work activity.

What are dangerous substances?

Dangerous substances are any substances used or present at work that could, if not properly controlled, cause harm to people as a result of a fire or explosion or corrosion of metal. They can be found in nearly all workplaces and include such things as solvents, paints, varnishes, flammable gases, such as liquid petroleum gas (LPG), dusts from machining and sanding operations, dusts from foodstuffs, pressurised gases and substances corrosive to metal.

What does DSEAR require?

Employers must:

find out what dangerous substances are in their workplace and what the risks are
put control measures in place to either remove those risks or, where this is not possible, control them
put controls in place to reduce the effects of any incidents involving dangerous substances
prepare plans and procedures to deal with accidents, incidents and emergencies involving dangerous substances
make sure employees are properly informed about and trained to control or deal with the risks from the dangerous substances
identify and classify areas of the workplace where explosive atmospheres may occur and avoid ignition sources (from unprotected equipment, for example) in those areas


Health and Safety Executive inspectors and Local Authority enforcement officers have wide-ranging powers to: enter premises; take samples and measurements; inspect documents; require persons to answer questions; and issue notices (prohibition notices, deferred prohibition notices and improvement notices).

They also have powers to prosecute. Those found guilty in a magistrate’s court of health and safety offences can face fines of up to £20,000 and/or up to 12 months’ imprisonment. Conviction in a Crown Court can result in an unlimited fine and/or a period of imprisonment of up to two years. [HSWA]

Industrial Emissions Directive

The objective of IED

The ultimate objectives of Industrial Emissions Directive (IED) are for the protection of human health and the environment by controlling emissions from industrial activities.

Major Provisions

The major provisions of IED include: permitting of installations, the setting and updating of Emission Limit Values (ELVs) to be based on Best Available Techniques (BAT), the establishment of BAT reference documents (BREFs) and the formulation of BAT conclusions that summarise the BREFs and the basis for compliance.

What does the IED apply to?

IED applies to industries including combustion and gasification. The IED applies to combustion installations with a combined rated thermal input of greater than 50MW.

ELVs are defined for SO2, NOx and dust for solid and liquid fuel fired plant. For gas fired plant, ELVs are defined for CO. For gas turbines ELVs are specified for NOx & CO only.

For gas fired plant with a rated thermal output of greater than 100MW, SO2, NOx and dust is required to be monitored on a continuous basis.

O2, temperature and water vapour must also be measured in order to correct the emissions to the required reporting conditions.


What is EN15267?

European standards cover the requirements for certification and for the manufacturer’s quality management system for manufacturing and design control of emissions monitoring systems.

EN 15267-1 Part 1: General aspects. Describes the roles and responsibilities of all parties involved in testing and certification.
EN 15267-2 Part 2: Minimum requirements for product quality assurance, initial assessment and on-going surveillance. describes the quality assurance requirements of the manufacturing and design processes. Therefore EN 15267-2 primarily applies to manufacturers of CEMS.
EN 15267-3 Part 3: Performance criteria and test procedures for automated measuring systems for monitoring emissions from stationary sources. It is required for the testing of CEMS under MCERTS:


It covers the first quality assurance level (QAL1) and third quality assurance level (QAL3) requirements of EN 14181 Stationary source emissions – Quality assurance of automated measuring systems. It provides a way to demonstrate compliance with the uncertainty requirements specified in the Industrial Emissions Directive (IED) (2010/75/EU).


What is EN14181?

EN14181 describes the quality assurance procedures required to ensure continuous emission monitoring systems (CEMS) measure emissions to air, are capable of meeting the uncertainty requirements on measured values required by the Industrial Emissions Directive (IED) (2010/75/EU).

EN14181 is designed to ensure that Continuous Emissions Monitoring System (CEMS) data that is reported to the regulatory authority is as accurate as possible. EN14181 defines three different Quality Assurance Levels (QAL1, QAL2, and QAL3) to achieve this objective. These QALs cover the suitability of a CEM for its measuring task (e.g. before or during the purchase of a CEM), the validation of the CEM following its installation, and the control of the CEM during its ongoing operation on an industrial plant.

Where do responsibilities lie in terms of EN14181?

(QAL 1) is the equipment suppliers’ responsibility

Demonstrates the potential suitability of a CEMS before installation.  MCERTS product certification at an appropriate range demonstrates compliance with the QAL1 requirements.

The Certified Range for each component within an analyser / analysers must be:

At least the Plant’s Emission Limit Value (ELV) x 1.5 (for WID Plants) e.g. If ELV for SO₂ is 50 mg/m³, instrument certified range must be ≤ 75 mg/m³
At least the Plant’s Emission Limit Value (ELV) x 2.5 (for LCPD Plants) e.g. If ELV for CO is 50 mg/m³, instrument certified range must be ≤ 125 mg/m³

Monitoring standard EN15267-3 Air Quality – Certification of Automated Measuring Systems (AMS) – Part 3: Performance standards and procedures for testing the performance of AMS of stationary source emissions.

(QAL 2) Responsibility is with the end user working with the equipment supplier

Calibrate the CEM and determine the variability of the measured values obtained by it; so as to demonstrate the suitability of the CEM for its application, following installation.

(QAL 3) is the End user responsibility

QAL3 is intended to provide an audited check on ongoing performance by conducting regular zero and span checks to ensure the monitors are consistent with those determined during QAL1 by comparing drift.

QAL3 tests for the CEMS can be controlled and recorded by the CDAS software. CDAS is a fully accredited data acquisition system.

Requirement on the operator to:

Install CEMS which meet certain quality criteria requirements (QAL1)
Calibrate these CEMS against Standard Reference Methods (3 years for WID, 5 years for LCPD) (QAL2)
Check the calibration function is still valid (Years 2 & 3 WID, Years 2, 3, 4, 5 LCPD) (AST)
Check the CEMS are working correctly, on a regular basis, with reference materials (QAL3)
Report the CEMS data, on a monthly basis, to the regulatory authority.

Once a year, the CEMS requires either:

Calibration by an MCERTS accredited Stack Emissions Test House (QAL2), or
Verification that it is still operating correctly and that any calibration functions derived during the QAL2 are still valid (AST)

General Rule is:

WID Plants – QAL2 every 3 years (with 2 x ASTs in between each QAL2)
LCPD Plants – QAL2 every 5 years (with 4 x ASTs in between each QAL2)

There are exceptions to this rule which include:

A change of fuel which changes the emissions profile = QAL2 may be required
If a CEMS system is changed / has a major component change = QAL2 may be required
An AST test fails = QAL2 required
Emissions are consistently low = Repeat ASTs may only be required in lieu of QAL2 (check with regulatory authority as permission in writing will be required for this)

The Annual Surveillance Test (AST). The IED requires annual checking of CEMS using manual reference methods to make sure the calibration function is still valid.

Report the CEMS data, monthly, to the regulatory authority using data acquisition software

Adequate measures to improve the reliability of the CEMS will be imposed should more than 3 hours of data be lost over 10 calendar days due to malfunction or lack of maintenance.

Overall, the EN 14181 standard has put more responsibility on the operator to continually prove that their installed CEMS meets the relevant performance standards

Failure to comply with the requirements of EN 14181 may well result in a breach of operating permits.

BS EN12021

What is BS EN12021 and what does it apply to?

Breathing air testing to BS EN12021 is necessary to ensure that the air supplied to a worker’s respirator is safe. Examples of respirators that need to be tested include;
Self-contained compressed air breathing apparatus used above and underwater (SCUBA) breathing air via an airline
Escape devices
Systems supplying synthetic air

What are the allowable limits of contaminants?

The standard specifies that in all circumstances all contaminants shall be kept to levels below the national occupational exposure limits as defined by the Health and Safety Executive (EH40).

Requirements are specified in the standard for permissible levels of oxygen, lubricants, odour, taste, carbon dioxide, carbon monoxide and water content in compressed breathing air.

BS EN 12021 states that breathing air should not contain any contaminants at a concentration which can cause toxic or harmful effects and in any event contaminants should be as low as possible and no greater than:-

Substance Allowable limit
Oxygen 21% ± 1% by volume
Carbon Monoxide As low as possible but not more than 5 ppm
Carbon Dioxide Not more than 500 ppm
Oil (droplets or mist) Not more than 0.5 mg/m3
Odour & Taste Without significant odour or taste
Water No free liquid water. Dew point to be >5 oC below the likely lowest temperature. Where conditions are not know the pressure dew point shall not exceed -11oC.

Where do the contaminants come from?

The air intake of a compressor may draw in carbon dioxide and carbon monoxide from an outside source. Carbon dioxide is an asphyxiant and carbon monoxide is toxic because of the way it reacts with the wearer of the respirator’s blood.

A failing air compressor pump or failing filtration can leave oil in the airline. This can release toxic volatile substances in the air.

The compressed air quality testing measures the amount of oxygen in the air because a dryer malfunction can reduce the oxygen to an unsafe level.

Water and water vapour dew point measurements are important to prevent the condensation or freezing of water in the airline. This could disrupt the supply of air to the user.

How often should testing take place?

The frequency of breathing air testing should be based on a risk assessment. However, it should take place at least every three months.  This should be more often when the quality of air cannot be assured at these levels.


Why is the F Gas Regulation Important?

The F-Gas regulation aims to reduce the contribution of the higher-GWP gases.

Requirements of the F gas regulation include phasing out HFCs steadily by reducing quotas and product bans.

It impacts anyone who:

Manufactures, uses or services equipment that contains F gases, like refrigeration and air conditioning systems, solvents or aerosols
Produces or wholesales F gas
Imports or exports F gas, or equipment containing F gas, to or from the EU

Refrigeration and air conditioning equipment requires mandatory documented leak checks according to how much damage could be caused to the atmosphere if the whole charge leaked.

The frequency of the test inspections is based on the GWP of the refrigerant multiplied by the estimated volume contained in each individual system – this gives the CO2e figure.

If the system contains between:

5 and 50 tonnes CO2e it requires one inspection per year.
50 to 500 tonnes CO2e require inspection every six months.
Greater than 500 tonnes CO2e require quarterly inspections.

The leak checking frequency can be halved if permanent gas leak detection systems are installed. Fixed refrigerant leak detection systems are mandatory for system charges of 500 tonnes CO2 equivalent and above.

How often does a system need leak checking?

R410A (2088 GWP) more than 2.39kg once a year, 23.9kg twice, more than 239kg four times
R407C (1774 GWP) more than 2.81kg once a year, 28.1kg twice, more than 281kg four times
R404A (3922 GWP) more than 1.27kg once a year, 12.7kg twice, more than 127kg four times
R134a (1430 GWP) more than 3.49kg once a year, 34.9kg twice, more than 349kg four times

For other refrigerants it is 5000 divided by its GWP to get the first inspections visit weight, then just move the decimal place one to the right to get the rest!

For more details about the latest F Gas Regulation Requirements click here.


EN140 is the European standard that covers the technical specifications for half masks. A half mask is defined as covering the nose, mouth, and chin. These types of mask usually have face pieces manufactured from natural or synthetic based rubber allowing the mask the flexibility to fit the contours of the face.

Half masks can come with a variety of different types of filter conforming to various standards:


Gas filters to remove specified gases & vapours or combined filters for removing solids, and /or liquid particles and specified gases and vapours. Each of the types of filters has three Classes; Class 1, Class 2, & Class 3.


Covers particle filters and these are classified according to their filtering efficiency. There are three classes of filter P1, P2 & P3. P1 filters are intended for use against solid particles only, P2 and P3 filters are subdivided according to their ability to remove both solid and liquid particles or solid particles only.


Deals specifically with AX filters. AX filters are designed for use against certain low boiling organic compounds. The filters are classified in only one type and class, AX. The maximum weight of filters that are allowed under the standards is 300 grams.