COSHH, Hazard signs and warning symbols Copy

COSHH-control of substances hazardous to health

COSHH is a law designed to protect people from injury, sickness or dangerous exposure while at work.

Hazardous substances are classified as anything that is capable of causing potential harm or injury upon contact or exposure to it. These could be anything from cleaning substances, dust and bodily fluids among others.

Employers duties for substance safety

Employers are bound by the law to:

  • Evaluate the risk level arising from substances and their relation to people around the work environment
  • Ensure interaction with workplace substances are as safe as possible.
  • Keep a close guard on the health of people at the workplace
  • Provide employees with necessary and effective guidelines, instructions and training regarding workplace health and safety and how to maintain the best possible standard.

Employee duties

The law binds employees to:

  • Duly cooperate with employers when using hazardous substances at work. 
  • Use protective equipment appropriately where required. 
  • Duly notify your employer in the event of protective clothing malfunction. 
  • Comply with medical examination requirements whenever needed

How Does A Substance Get into Your Body?

Substances can infiltrate your body through:

  • Respiratory tracts, mouse and nose
  • Oral ingestion
  • Absorbing through coming into contact with your skin or eyes. 
  • Entry through breaks in your skin, such as cuts or abrasions. 
  • Some substances can injure us straight away, such as irritated eyes if you splash bleach into them. 
  • For other substances, it takes repeated exposures before you see anything like dermatitis on your hands. That happens over a long time. 

COSHH, how can exposure happen? 

Accidents could be caused by: 

  • Splashing substances.
  • Not following the manufacturer’s instructions.
  • Not having or wearing the correct protective clothing (PPE). 
  • Mixing substances together that should not be mixed. For example, bleach with other cleaning products. 
  • Not taking the correct precautions. For example, using a substance in a confined space when the label says using only a welfare ventilated area.
  • Using the substance for something you are not supposed to. For example, cleaning toilets with oven cleaner. 
  • Not rinsing away detergents properly before using bleach, 
  • Incorrect storage or disposal of substances or waste products. 
  • Spillage is not being cleaned up straight away, causing slips or falls or contact with the substance spilled. 
  • Storing chemicals in inappropriate and unlabelled containers

Hazard symbols & Warnings

We take a look at some of the most common symbols and warnings displayed on some substances in the workplace:

  • Irritant
  • Substances that cause uneasiness or irritating sensation upon contact with eyes or skin.
  • Corrosive
  • Substances that cause a burning effect if ingested or gets in contact or skin.
  • Flammable.
  • A symbol depicting either flammable, highly or extremely highly flammable substance could potentially catch flames if exposed to heat or naked flames

These are some of the symbols that require the attention of a line manager:

  • Toxic or very toxic.
  • Dangerous to the environment.
  • Oxidising
  • Explosive

COSHH – Reducing the risk

If it is absolutely necessary to work with hazardous material, these are some of the considerations to be made:

  • Is there anything that can be done to enhance safety levels?
  • Is it absolutely necessary to use hazardous material?
  • Are there any viable alternatives?
  • If the above questions cannot be satisfactorily answered, then you should consider the use of protective gear as the very last resort.

Sources of hazardous information

These are the informative sources of useful knowledge regarding the substances and materials used at the workplace.

An ideal COSHH assessment should reveal; the potential risk level, possible counteractive measures as well as precautionary measures that can be put in place to ensure a workplace is as safe as it can be.

  • The manufacturers
  • Safety data-sheet
  • Product label
  • Occupational safety team
  • Chemical labelling

Substance and material labels may include:

  • Manufacturers identification and location details
  • Purpose and potential risks associated with the use of the substance
  • symbols and hazardous warnings
  • Instructions for use
  • What precautions you should take, 
  • what protective clothing you should wear when using the substance. 
  • The label may also include what to do if you get it on your skin or in your eyes. 
  • Storage and safe disposal of the container
  • Product data-sheets should be made available at a workplace to provide more information regarding substances being used

The safe use of bleach

The following have been identified as areas where bleach solutions can be used:

  • The Daily disinfection of lavatories, washbasins and sluices.
  • Periodic disinfection of baths, commodes, laundry work surfaces, plastic mattress and pillow covers. 
  • Disinfection of an area after containment of blood
  • Body fluid or sharps spillage. 
  • Avoid pouring bleach down drains or plug holes as cleaning is much more important. The amount of bleach solution you use to wipe down the inside with is enough to sanitize.
  •  Most health care and hospital settings use a tablet form of bleach. 
  •  Ensure that the bleach solution is prepared and used in accordance with the manufacturer’s instructions.
  • Disposal of bleach solutions must be in accordance with local policies and procedures. 
  • Bleach tablets must be stored correctly and safely and secured away from patient areas.

The Do’s and Don’ts When Using Hazardous Substances At Work


  • Read the COSHH assessment to find out how to use the product safely. 
  • Follow any safe working procedures that are in place. 
  • Read the warnings On the label before you use the substance, and follow the advice given.
  • Report any problems with your protective clothing to your supervisor.
  • Wash your hands thoroughly before touching food, drinks, cigarettes or makeup 
  • Work in a safe and sensible way. 


  • Don’t mix cleaning substances together, especially bleach with any other product, as you could produce chlorine gas, which is toxic.
  • Don’t use anything in an unmarked bottle.
  • Don’t splash cleaning products about  ¾ don’t use any substance you’re unsure about. 
  • And don’t forget to use your personal protective equipment

Quick Recap

We have taken a look at COSHH, and how to safely manage substances and potentially hazardous material in a workplace, common labels and symbols that may come with those substances, and how to go about working with hazardous substances.