The Storage of Substances Hazardous to Health

Many organisations need to store substances that are classified as hazardous to health, sometimes in substantial quantities.  Several sets of Regulations may apply, depending on the exact nature of the substance being store, but in nearly every case, the Control of Substances Hazardous to Health Regulations 2002 (or COSHH Regulations) will apply.  COSHH applies as much to the storage of substances hazardous to health as it does to their manufacture and use.  Many aspects of the safe storage of substances hazardous to health rely on common sense and part of the purpose of the COSHH risk assessment is to formalise the application of this common sense.

Risk Assessment

Risk assessment is the cornerstone of modern health and safety management.  The need to carryout risk assessments is identified in Regulation 3 of the Management of Health and Safety at Work Regulations 1999, as amended:

Every employer shall make a suitable and sufficient assessment of - 

• the risks to the health and safety of his employees to which they are exposed whilst they are at work; and
• the risks to the health and safety of persons not in his employment arising out of or in connection with the conduct by him of his undertaking.

In the case of stored substances, risk assessments may also required by other pieces of legislation, such as the Control of Substances Hazardous to Health Regulations 2002 or the Dangerous Substances and Explosive Atmosphere Regulations 2002.  It is not necessary to carryout two (or more) different) risk assessments is all of the relevant points are contained in a single risk assessment.  It would be acceptable for a single risk assessment to deal with the safe storage of substances, provided it dealt with the hazardous nature of the materials being stored, as well as the fire and explosion risks, etc.

Materials that are not substances hazardous to health, but are still dangerous

As well as the health risks associated with substances, there are other risks that may not be accounted for (or may be missed) if the only form of risk assessment is a COSHH Assessment.  There are several categories of hazard that do not form part of the COSHH assessment, but which, because of the risks that they create, still need to be considered by any organisation storing the substances.  These include issues such as fire and explosion, radioactive substances, substances stored under pressure and quantities of certain substances that bring the COMAH Regulations into consideration.  It should also be considered that several materials will be classified as substances hazardous to health and will have other hazards associated with them.  

Flammable and Highly Flammable Substances

The hazards flammable and highly flammable are not relevant under COSHH.  Historically, the storage of flammable and highly flammable substances (such as solvents, thinners, paints, petrol and other fuels, etc.) was covered by the Highly Flammable Liquids and Liquefied Petroleum Gases Regulations 1972.  These Regulations were revoked by the Dangerous Substances and Explosive Atmosphere Regulations 2002 (DSEAR).  DSEAR introduced a risk assessment based route for consideration of storage arrangements and removed the requirement for a Petroleum License (previously under the Petroleum Act 1928) and replaced this with a risk assessment based approach to storage. The storage of flammable and highly flammable substances should be subject to a risk assessment (or DSEAR) and may have an impact on the fire safety assessment for the premises, as required by the Regulatory Reform (Fire Safety) Order 2005.

Explosives

Materials that are dangerous only because they are explosive are outside of the COSHH Regulations.  The storage of such materials falls under the new Manufacture and Storage of Explosives Regulations 2005.  Businesses that store fireworks require registration or licence from the local authority (Trading Standards).

Pesticides

The use and storage of pesticides is governed by the Control of Pesticides Regulations 1996 (as amended). 

Radioactive Substances

Where substances are considered to be hazardous because they are radioactive, then these substances are not covered by the COSHH Regulations, but by the Ionising Radiations Regulations 1999.

COMAH Regulations

Storage of certain materials in amounts over their threshold levels may bring the organisation within the ambit of the COMAH Regulations (Control of Major Accident Hazards Regulations 1999).  The substances, along with their threshold quantities are listed in Schedule 1 of the COMAH Regulations.

General storage considerations

There are some general points that apply to nearly all storage arrangements.  These include:

Labelling

It should be ensured that all substances are labelled suitably.  The label should identify the substance and the hazards that are associated with the substance.  It should be legible and should be kept clean.  Where appropriate, pipe and duct work should also be labelled, preferably in accordance with the colour based identification system described in BS 1710.

Hazard identification

The substance, and any associated pipe work, etc. should be labelled to identify the hazard(s) associated with the substance.  This may take the form of words or of the orange square with appropriate warning symbol(s).  

Safety Signs

Suitable safety signs, designed in accordance with The Health and Safety (Safety Signs and Signals) Regulations 1996 (as amended), should be displayed in appropriate positions within the work and storage areas.   These should highlight the presence of (various classes of) hazardous substance and indicate what type of personal protective equipment should be worn.  These should supplement, not replace, the risk assessment.

Provision of information

Suitable and sufficient information must be made available, to those who may be exposed to the substances being stored, of the hazards associated with the substance and of the measures to be taken in the event of an uncontrolled or unexpected release of the substance, such as dealing with leaks and spillages.  This should include, but must not be limited to, an up to date copy of the appropriate materials safety data sheet.  The COSHH Regulations make it explicit that a suitable and sufficient COSHH assessment does not comprise solely of a collection of material safety data sheets.

Staff training

Staff should be provided with suitable and sufficient training in the safe use and handling of the hazardous substance.  This relates to the hazards associated with the substance and the control measures to be employed to protect themselves, and others, from harm.  This must include information on the appropriate use of extraction equipment, other engineering controls, personal protective equipment, etc.  Staff must also receive appropriate training in dealing with spillages, leaks and other accidental releases of substances hazardous to health.  Training should also include the actions to take in response to a spillage or other accidental release.  

First Aid Provision

In addition to normal workplace first aid, any special first aid provisions should be based on the risk assessment findings (COSHH and other assessments).  This may include provision of emergency eye wash facilities (such as for the storage of corrosive substances) and any specialist first aid training or equipment.  These may include:

• breathable oxygen bottles for dealing with cases of (suspected) cyanide poisoning, or
• calcium gluconate gel for treating hydrofluoric acid burns.  

Spillage (or release) procedures

Suitable, safe procedures for dealing with spillages, or releases, of the hazardous substance must be developed and staff must receive adequate training.  Spillages must be cleaned up promptly and disposed of safely.  Where appropriate, spillage response kits should be provided.  Depending on the likely nature of any spillage, these response kits should contain: brushes, temporary bunding materials, epoxy based emergency filling materials, vacuum cleaning equipment (fitted with a filter corresponding to type H of BS 5415 for toxic dusts), pumping equipment (flameproof if required), appropriate personal protective equipment, absorbent granules, etc. as is deemed appropriate from the COSHH and other risk assessments.  In many cases, the availability and condition of these kits should be checked periodically. Depending on the level of risk, it may be necessary to simulate spillages and practise the responses.  

Active Monitoring

The condition of the storage facilities and the stored materials should be checked regularly and suitable records maintained.  Further to this, the work practices and procedures should be monitored to ensure that suitable practices are adhered to and to ensure that short-cuts and poor practices are not allowed continuing.  Active monitoring may be used to ensure that the control measures identified in the risk assessment process are used and are effective.

Protection from extremes of temperature

Some substances are sensitive to extremes of temperature.  Heat may cause some substances to change form (melting or vaporisation), leading to loss of containment or even cause some substances to decompose, changing the chemistry and, hence, the risks.  Some substances need to be protected from freezing.  Glacial acrylic acid, for example, is stabilised by the addition of methyl ethyl hydroquinone (MEHQ).  Phase separation on freezing leads to loss in stabilisation and can lead to serious problems (such as explosive polymerisation) on thawing.  Information of susceptibility to extremes of temperature may be found on the materials safety data sheet.

General ventilation

Appropriate levels of general ventilation must be provided to prevent the build up of vapours, fumes and dusts.  This may be achieved by a combination of natural and mechanical means.  There is obviously a strong overlap with fire safety issues for the storage of flammable and highly flammable materials.

Storage packaging/vessels

The integrity of the storage vessel or packaging is an important factor in the control of exposure to hazardous substances in storage.  There are various sets of regulations (such as the Chemical (Hazard Information and Packaging for Supply) Regulations 2002) that require the manufacturers/suppliers to package substances safely.  Containers need to be of an appropriate UN Performance Tested type and need to be suitable for the storage conditions (or storage conditions need to be suitable for the type of container/packaging).  

Amount of materials stored

Where possible, the risks from hazardous substances can be reduced by decreasing the amount of each substance stored.  This is also a simple, but useful method for ensuring that the operation does not fall within the scope of the COMAH Regulations.

Vessel Cleaning

Periodically, some storage vessels will need to be cleaned.  A risk assessment must be completed for this operation having regard to the substances present and to any additional risks, such as those arising from any confined space work, etc.  Such work may need to be carried out under a suitable permit to work.  The provision of the Confined Spaces Regulations 1997 should be implemented where appropriate.

Summary

The COSHH Regulations require employers to prevent exposure to substances hazardous to health to both employees and non-employees where it is reasonably practicable to do so.  Where it is not reasonably practicable to avoid exposure, then exposure must be controlled adequately.  Hence, COSHH assessments must consider the storage of substances and their accidental release as well as their use.  It may be necessary to supplement the COSHH risk assessment with other assessments (or to carry out a combined assessment) where other, non-COSHH, hazards exist (such as the storage of highly flammable, explosive or radioactive materials).  

Michael Ellerby

LLB BSc CMIOSH MIIRSM MIFSM CChem MRSC CSci

Director

LRB Consulting Limited

Tel 01509 550023

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