Control of Substances Hazardous to Health (COSHH)

The easiest way to see if a potentially hazardous substance is classified as hazardous in terms of COSHH is by looking for the relevant hazard warning symbol, which is displayed in the diamond-shaped pictograms below and is outlined in red with a black symbol.

There are 9 hazard categories according to COSHH:

• Explosives
• Flammable
• Oxidising
• Gas under pressure
• Corrosive
• Toxic
• Health hazards
• Serious health hazards
• Dangerous for the environment

Importance of COSHH Risk Assessments

If you do use any products in your workplace or work activities that display any of these symbols, it is important an appropriate COSHH risk assessment is also undertaken – over and above any general workplace risk assessments that may have already been completed.

This is to ensure the hazards and risks of using these products have been fully considered and all relevant control measures are in place.

A fundamental aspect of the COSHH risk assessment is that it considers all parts of the process, in which the hazardous substance is stored and used, as the necessary risk control measures may change throughout different parts of the process—from storage, through transport within the site, normal use, and disposal.

Example Questions of a COSHH Risk Assessment

If we consider a cleaner diluting a concentrated (corrosive) cleaning agent into 10 litres of water to mop a floor – here are the types of questions the COSHH risk assessment needs to ask and answer:

• Where is the neat, corrosive hazardous substance (the cleaning agent) being stored?
• How does the person about to use it carry the neat product to the point of use?
• How is the neat product diluted with water, and in which order should the liquids be mixed?
• How should any spillages be treated, mopped up, and disposed of?
• How should any unused or leftover solutions be disposed of?
• What general clothing and specific personal protective equipment (PPE) should be worn?

The COSHH Regulations require a specific risk assessment process is undertaken to determine the level of employee exposure to hazardous substances whilst that product is being used.

In general, the risk from using hazardous substances will be dependent on the quantity of the substance an individual is exposed to and how often they may be exposed.

Routes of Entry for Hazardous Substances

There are 4 typical routes of entry for hazardous substances in the human body.

• Inhalation: Breathing the substance in along with normal air intake.
• Absorption: The substance encounters the skin and enters through the pores.
• Ingestion: The substance enters through the mouth and is swallowed into the stomach and the digestive system.
• Injection: The substance enters through a wound or some other break in the skin.

If we refer to the example of a cleaner, it is most likely in this instance, splashes that might be evolved whilst diluting the product, producing small liquid droplets, could contact the skin, eyes and mouth.

Where COSHH risk assessments are considering products that are typically found in gaseous or vapour form, inhalation would be the most likely route of entry.

Hierarchy of Control

Elimination

Whenever any kind of risk assessment is undertaken, the hierarchy of control is typically used to evaluate potential control measures. In all cases, the best thing to do with a hazard is to get rid of it, which is elimination.

Although top of the hierarchy of control, elimination is not always possible, for example if we need to use a particular glue or solvent for a specific job, then eliminating it isn’t very helpful.

Substitution

Substitution is the next best option, so not eliminating the hazard, but reducing its impact.

If a cleaning product is needed and, in order to do its job effectively, the formulation contains certain hazardous chemicals within its composition, for example, it’s corrosive, if we were able to substitute this for another formulation, even though this second product might still be deemed a health hazard, nevertheless we have decreased the relative harm that this second hazardous substance is able to do and thereby reduced the risk.

PPE

Personal Protective Equipment (PPE) will most likely always feature somewhere within risk controls, but it should always be considered last and never as the first control measure to be implemented.

Acute vs. Chronic Effects

The COSHH risk assessment process always needs to consider whether exposure to a given substance is likely to result in acute or chronic effects.

Acute effects:

• Short duration and appear fairly rapidly.
• Usually during or after a single or short-term exposure to a hazardous substance.
• May be significant but are usually reversible.

Chronic effects:

• Develop over a period which may extend to many years.
• Produced from prolonged or repeated exposure to hazardous substances.
• Result in a gradual, latent and often irreversible illness, which may remain undiagnosed for many years.

Special Case: Asbestos Exposure

One hazardous substance that has a unique latency before its chronic effects are realised is exposure to asbestos fibres.

Asbestos is resistant to heat as well as chemical attack. Recognised for its insulating properties, it was used extensively either as fibres, boards, or mixed / woven into other products.

The fibres, once airborne, can be breathed in, and due to their very small size, can be carried deep into the lungs. Once inhaled, these fibres can penetrate deep into the lungs, where they can lie dormant for up to 40 years before potentially causing mesothelioma.

Some building or maintenance work will occasionally disturb the fabric of the workplace. In older buildings, certainly those constructed before 2000, it is possible asbestos may be present in numerous typical workplace locations.

Get Health & Safety Support for COSHH Compliance

If you’re uncertain whether your organisation has all the necessary COSHH control measures in place or need guidance on managing hazardous substances at work safely, now would be a good time to seek out more information from the Avensure Health and Safety team. Simply click here: Avensure Contact