Sc20 – Gases And Dusts

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 ​Launch powerpoint


  • 1. Purpose
  • 2. Scope
  • three. Definitions
  • 4. Responsibilities

    • four.1 Group Leaders
    • 4.2 Supervisors/Line Managers
    • four.3 Staff, users, visitors, tenants and contractors
    • four.4 SHE Group
  • Appendices

    • Appendix 1 – Background Information: Requirements of DSEAR
    • Appendix 2 – Detailed DSEAR Guidance
    • Appendix three – Guidance completing hazard checks in regions where gaseous explosive dangers exist
    • Appendix four – Example risk evaluation for the small scale laboratory use of Solvents
    • Appendix 5 – Example risk evaluation for using Hydrogen Supplied from a Gas Cylinder in an Experiment
    • Appendix 6 – Training
    • Appendix 7 – Audit Checklist

    • Appendix eight – References​
    • Appendix nine – Document Retention Policy


Initial lau​nchNovember 20081.1Update to BS ENs in ReferencesOctober 20121.2Amendment to audit checklistMay 20131.3Minor alternate to para four.2.1February 20141.4

Add Document retention policy

August 2014


Changes to responsibilities and action volumesJanuary 2015


​Changes to mirror updating of DSEAR regulation, permitted codes of practice, and applicable standards.

​March 2018


​Update to mirror the launch of SHE Assure

​October 2018​

1. Purpose

Dangerous materials may be observed in nearly all places of work and encompass such things as solvents, paints, flammable gases, dusts from machining and sanding operations.

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (as amended)(DSEAR) require employers to evaluate the risks of fires and explosions that can be due to risky substances within the workplace and then do away with or lessen these dangers as a long way as in all fairness doable. The Regulations clarify the present necessities to manipulate fireplace and explosion dangers which are set out inside the Management of Health and Safety at Work Regulations 1999.

Gases which might be under strain (e.g. gasoline in a cylinder) may additionally gift a danger of explosion if no longer effectively treated inside the administrative center. Substances which could corrode metals should cause structural damage decreasing integrity of systems if now not definitely contained. From June 2015, DSEAR places a formal requirement to evaluate the dangers for materials if classified for these houses and put in location suitable control and mitigation measures. The need to perform a danger assessment and feature in place processes for the secure use of chemical substances formerly now not protected with the aid of DSEAR are already required by means of the overall necessities of the Health and Safety at Work etc Act 1974 and the Management of Health and Safety at Work Regulations 1999. STFC are already handling these responsibilities in the STFC Safety Code explos info framework and so aren’t taken into consideration similarly within SC20.​ 2. Scope

The application of DSEAR inside the technically complex and specific environments that exist in the STFC is past the capability of this code to cope with in full. This code does not endeavour to explain how the dangers from all dangerous materials and explosive atmospheres risks ought to be managed, alternatively it establishes a framework upon which to perform easy tests. For technically complex environments the recommendation of able experts is required and ought to be engaged in a timely manner.

The necessities of this code apply to all STFC staff, tenants, facility customers and site visitors and observe in any example wherein risky substances are gift, used or produced. The necessities of this code observe to facility consumer / tourist system and experiments.

The obligation to adopt a danger evaluation for contractor activities lies with the contractor’s control, however it’s far the STFC responsibility to make certain the threat checks are in place and the ability dangers are completely understood before work commences. All applicable facts to allow the chance evaluation to be undertaken with the aid of the contractor’s management have to be furnished.

Although DSEAR applies to pressurised systems (>2barg) this Code does now not practice to pyrophoric materials or stress systems which have the potential to result in hearth and / or explosion, see related SHE codes for COSHH and Pressurised Systems .

This code does no longer address other hazardous homes associated with flammable substances. For example toxic hazards are addressed underneath COSHH, radiation risks (e.g. tritium), are addressed in relevant radiation control SHE codes and with the aid of recommendation from SHE Group. These extra hazards ought to be assessed one by one. Specific steering within the managing and use of hydrogen and deuterium can be received by using contacting the SHE Group.

Also, the usage of risky materials in constrained spaces may create further dangers. This code does no longer address the hazards bobbing up from restrained areas, see STFC SHE Code eleven Work in Confined Spaces. 3. Definitions 3.1 DSEAR

Dangerous Substances and Explosive Atmospheres Regulations 2002. These rules follow in any place of job in which dangerous materials are gift, used or produced, with some minor exceptions (discuss with Appendix 1).

3.2 ATEX

ATEX is the name commonly given to the framework for controlling explosive atmospheres and the requirements of gadget and shielding systems utilized in them. It is derived from the French ATmosphére EXplosif. It is based totally at the necessities of European Directives from which DSEAR is derived, and that are described in more element in Appendix 1. three.3 EPS regulations

Equipment and Protective Systems for Use in Potentially Explosive Atmospheres Regulations 1996 (as amended) (EPA). DSEAR requires that new device and protective structures for use in risky areas have to be decided on on the idea of the requirements in those rules. 3.four Dangerous materials

Any substances that could, if not well controlled, purpose harm to human beings as a result of a hearth, explosion or similar energetic event. A extra unique definition is to be had in Appendix 1. 3.five Risk evaluation

A manner wherein the explosion (or flammable) dangers in a selected vicinity or of a selected activity, arising from the presence, use or production of risky materials, are diagnosed and the extent of fireplace / explosion chance expected taking account of the effectiveness of current control measures in location. three.6 Hazard Areas Classification (HAC)

“Hazardous Areas” in DSEAR are “any location wherein an explosive environment may also occur in quantities which includes to require special precautions to shield the protection of workers”. Consequently Hazardous Area Classification is the system of assessing:

  • the likelihood that an explosive environment will exist;
  • how voluminous it is going to be; and
  • how lengthy the environment could exist for (time) given variables along with air flow, fee of fabric manufacturing/leakage etc.

For gases and vapours the evaluation method will classify the area into one in every of three zones:

  • Zone 0: An place in which an explosive gas ecosystem is gift continuously for long durations;
  • Zone 1: An area wherein an explosive gasoline surroundings is possibly to arise in normal operation; or
  • Zone 2: An vicinity wherein an explosive gas environment is not probable to arise in ordinary operation and, if it does arise, will most effective exist for a short time.

For dusts, powders and flyings the assessment procedure will classify the location into certainly one of three zones:

  • Zone 20: A area wherein an explosive environment in the form of a cloud of flamable dirt in air is present continuously or for long intervals or frequently;
  • Zone 21: A vicinity in which an explosive ecosystem in the form of a cloud of combustible dust in air is likely to occur in regular operation now and again;
  • Zone 22 – an area in which an explosive ecosystem in the form of a cloud of combustible dirt in air is not probably to occur in ordinary operation however, if it does occur, will persist for a short length only.

Additionally, skinny layers (i.e. 1mm) of combustible dust can be roused to flammable awareness. Therefore, dirt layers within the place of work are in all likelihood to be classificed as Zone 22. three.7 Explosive environment

In DSEAR, an explosive ecosystem is defined as a mixture of dangerous materials with air, under atmospheric conditions, in the form of gases, vapours, mist or dust wherein, after ignition has befell, combustion spreads to the whole unburned aggregate.

Atmospheric conditions are usually known as ambient temperatures and pressures. That is to say temperatures of –20°C to forty°C and pressures of 0.8 to 1.1 bar.

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