Safety, Health & Environment Section
FM SHE 025
Procedural Guidance for the
Control of Dangerous Substances
and Explosive Atmospheres
(DSEAR)
April 2011
Version 2.0
Document review due: April 2013
Please Note :This is a controlled document, please ensure you are using the most recent
version.
Contents
Page
1.0
Introduction
3
2.0
Scope
3
3.0
Purpose
3
4.0
Definitions
3
5.0
Legal Requirements
4
6.0
Procedural Guidance
5
6.1.1
5
6.3
Risk Assessment
Existing activities/processes involving dangerous
substances
New
activities/processes
involving
dangerous
substances
Recording the significant findings of the risk
assessment
Review of risk assessments
Elimination or reduction of risks from dangerous
substances
Zoning explosive atmospheres
6.3.1
Signage
8
6.3.2
Equipment suitability for explosive atmospheres
Arrangements to deal with accidents, incidents and
emergencies
Information instruction and training
Identification of hazardous contents of containers and
pipes
Summary of responsibilities
8
6.1.2
6.1.3
6.1.4
6.1.5
6.2
6.4
6.5
6.6
7.0
8.0
5
5
6
6
7
7
9
9
10
10
11
Appendix 1a
References
Example DSEAR Risk Assessment Oxyacetylene
Welding
Appendix 1b.
Example DSEAR Risk Assessment Paint Spraying
Workshop
17
Appendix 1c.
Example DSEAR Risk Assessment Woodworking
Workshop
20
Appendix 2
Practical Application of DSEAR
23
Appendix 3
Suitability of Equipment for Hazardous Zones
25
Page 2 of 26
12
1.0 Introduction
The specific legal requirements of the Dangerous Substances and Explosive
Atmospheres Regulations (DSEAR) 2002 were introduced for new workplaces on the
30th June 2003.
DSEAR requires employers such as the University to assess the risk of fires and
explosions that may be caused by dangerous substances in the workplace. These
risks must then be eliminated or reduced as far as is reasonably practicable. The aim
is to protect staff and other people who may be put at risk, such as students,
contractors and visitors to the workplace.
2.0 Scope
This procedural guidance must be applied to all University workplaces and activities
which contain or use dangerous substances. The following examples illustrate the
types of activities undertaken using dangerous substances that may be covered by
DSEAR:
 storage of petrol as a fuel for cars, boats or horticultural machinery;
 use of flammable solvents in laboratories;
 use of flammable gases, such as acetylene, for welding or cutting;
 use of flammable gases, such as LPG or natural gas for heating (other than for
domestic use);
 processes and activities which create combustible/flammable waste dusts, for
example in woodworking workshops;
 storage and handling of flammable wastes such as fuel oils;
 storage and use of solvent based paints and resins;
 storage and handling of aerosols with flammable propellants such as LPG;
 transport of flammable substances in containers around the workplace.
3.0 Purpose
This procedural guidance has been produced to ensure there is a consistent and
comprehensive approach across the University to the management and control of
dangerous substances in the workplace. By following the guidance, the risks
associated with the use of dangerous substances should be eliminated or reduced so
far as is reasonably practicable.
In general the majority of issues surrounding risks to safety from fire and explosion
should have been addressed in general and/or activity specific risk assessments.
Therefore the impact of DSEAR should be minimal.
4.0 Definitions
Dangerous substances include:
 substances or mixtures of substances classified as explosive, oxidising,
extremely flammable, highly flammable, or flammable under the current
Chemicals (Hazard Information and Packaging for Supply) Regulations 2002
(CHIP);
Page 3 of 26
 any kind of dust that when spread in air to form a cloud can explode;
 any other substances, or mixtures of substances, which because of their physical
properties and the way in which they are present in the workplace create a risk to
safety from fires and explosions, but which may not be covered by CHIP. For
example high flashpoint liquids present in the workplace at elevated
temperatures.
 A Flammable Liquid is one with a flash point less than 55oC
 A Highly Flammable liquid is one with a flash point less than 21oC
 An Extremely Flammable is one with a flash point less than 0oC and a boiling
point of 35oC or less.
 A highly flammable solid is one which is spontaneously combustible in air at
ambient temperature or one which readily ignites after brief contact with a flame
or one which evolves highly flammable gasses in contact with water or moist air.
 Auto-ignition temperature is the minimum temperature at which a material will
ignite spontaneously under specified conditions.
 Flashpoint is the minimum temperature at which a flammable vapour under
specified conditions, gives of enough vapour to ignite momentarily on the
application of an ignition source.
 Lower Explosion Limit (LEL) the minimum concentration of vapour in air below
which the propagation of a flame will not occur in the presence of an ignition
source.
 `Workplace' means any premises, or part thereof, used for work. This includes
all industrial, commercial and educational premises, vehicles, vessels, roads,
houses and other domestic dwellings, and common parts of buildings.
 ‘So far as is reasonably practicable’ has been interpreted by the courts as
allowing economic considerations, as well as for example time or trouble to be
taken into account as factors to be set against the risk.
5.0 Legal requirements
DSEAR applies whenever the following conditions are met:
 There is work being carried out by an employer or self-employed person;
 A dangerous substance is present, or is liable to be present at the workplace;
 The dangerous substance presents a risk to the safety of persons (as
opposed to health).
DSEAR requires the University to:
 identify what dangerous substances are used in the workplace and what the fire
and explosion 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 and trained to control or deal with
any risks from the dangerous substances;
Page 4 of 26
 identify and classify (zone) areas of the workplace where explosive atmospheres
may occur and avoid ignition sources (from unprotected equipment, for example)
in those areas.
Failure to comply with DSEAR is a criminal offence and may also leave the University
open to civil proceedings.
6.0 Procedure
6.1.1 Risk Assessment
Where dangerous substances are identified as being present in the workplace,
DSEAR requires the University to undertake a suitable and sufficient assessment of
the risks arising from those substances. The purpose of the assessment is to
determine what measures are necessary in order to eliminate or reduce the risk so
far as is reasonably practicable.
The risk assessment should include amongst other considerations:
 The hazardous properties of the substance;
 The combination of the properties of the substance, and the circumstances of the
work process that have been assessed;
 The likelihood and persistence of explosive mixtures;
 Potential presence of ignition sources;
 The general working environment;
 Activities such as maintenance, which may heighten the risk;
 The accidental release of a dangerous substance and how they are dealt with;
 Provision of safety information;
 Effects of measures taken;
 Areas appropriately classified into zones;
 Use of appropriately protected equipment.
It should be noted that under Regulation 5 of DSEAR the requirement to assess risks
from dangerous substances should not be considered in isolation. It should be
carried out as part of the overall risk assessment process required by The
Management of Health and Safety at Work Regulations 1999
6.1.2 Existing activities/processes involving dangerous substances
A review of existing risk/Control of Substances Hazardous to Health (COSHH)
assessments should be undertaken to ascertain whether in fact they cover the
requirements of a DSEAR assessment and the necessary control measures to
comply with DSEAR have in fact been identified and implemented.
6.1.3 New activities/processes involving dangerous substances
New work involving a dangerous substance must not commence before an
assessment has been made, or before the implementation of the control measures
required by that risk assessment.
Dangerous substances are defined under the CHIP Regulations 2002, as substances
or preparations that are classified as explosive, oxidising, extremely flammable,
highly flammable or flammable.
Where dangerous substances are supplied for use at work, CHIP requires the
supplier to provide a safety data sheet. These should be used to assist in the
Page 5 of 26
assessment of the physical and chemical properties of the substance/s in relation to
the activity/process being undertaken.
Additionally DSEAR requires the identification of dangerous substances and the
hazards they present which are:
 Brought into the workplace and handled, stored and used;
 Produced or given off (e.g. as fume, vapour, dust, etc) by a process or activity, or
as the result of an incident or accident;
 Used for, or arise from, maintenance, cleaning, and repair work; or
 Produced as a by product of any work process (e.g. waste, residues, etc);
 Naturally occurring in the workplace (e.g. methane in tunnelling operations).
If the assessment highlights a risk to persons arising from fire, explosion or other
energy-releasing events (e.g. vapours or gases produced during a laboratory
technique, substances that decompose, or react exothermically, when mixed with
other substances e.g. peroxides), then the substance is a dangerous substance for
the purposes of DSEAR.
It should be noted that some fine dusts (particularly organic) forming a ‘cloud’ effect
in air can, in certain circumstances be ignited and explode. Therefore, wood and
many other fine dusts such as flour (may be classified as dangerous substances
depending on the circumstances of the work, particularly if this involves grinding,
sanding or machining.
Many dangerous substances may also pose a risk to health as well as safety and
would therefore also be covered by the requirements of the COSHH Regulations
2002. In such cases it is advised to address the risks of fire and explosion at the
same time as undertaking the COSHH assessment.
For those dangerous
substances which do not pose a risk to health, DSEAR must be addressed at the
same point as the general risk assessment for new activity/processes.
Appendix 1 has example risk assessments which only include fire and explosion type
hazards, these may be useful for reference purposes when considering the broader
risks of an activity/process which includes the use of a dangerous substance/s.
6.1.4 Recording the significant findings of the risk assessment
Whichever method is used and whether as part of a new or existing risk assessment,
DSEAR requires the recording of the significant findings of the assessment. This
should include:
 The measures (technical and organisational) taken to eliminate and/or reduce
risk;
 Sufficient information to show that the workplace and work equipment will be safe
during operation and maintenance including;
 Details of any hazardous zones;
 Any special measures taken to ensure co-ordination of safety measures and
procedures, where employers share a workplace;
 Arrangements taken to inform, instruct and train employees.
6.1.5 Review of risk assessments
The risk assessment should be reviewed regularly and when changes have occurred
that invalidate the original assessment.
Page 6 of 26
6.2 Elimination or reduction of risks from dangerous substances
DSEAR requires the University to avoid, so far as is reasonably practicable, the
presence or use of a dangerous substance in the workplace by replacing it with a
substance or process which either eliminates or reduces that risk.
Where this is not reasonably practicable, DSEAR requires that control measures be
applied in the following order of priority, consistent with the risk assessment and
appropriate to the nature of the activity or operation:







Reduce the quantity of dangerous substances to a minimum;
Avoid or minimise releases;
Control releases at source;
Prevent the formation of explosive atmospheres;
Collect, contain and remove any releases to a safe place (e.g. by ventilation);
Avoid ignition sources;
Avoid adverse conditions (e.g. exceeding the limits of temperature or control
settings) that could lead to danger;
 Segregate incompatible substances.
Measures that mitigate the risk (e.g. measures that limit the harmful physical effects
resulting from fire or explosion) must also be applied and these should likewise be
consistent with the risk assessment and appropriate to the nature of the activity or
operation. These should include:





Reducing the number of persons exposed;
Providing measures to avoid the spread of fire and explosion;
Providing explosion suppression or explosion relief equipment;
Providing plant which is explosion resistant;
Providing suitable personal protective equipment (PPE).
DSEAR also specifies that the measures taken to achieve the elimination or the
reduction of risk should include:
 Design, construction and maintenance of the workplace (e.g. fire-resistance,
explosion relief, etc);
 Design, assembly, construction, installation, provision, use and maintenance of
suitable work processes, including all relevant plant, equipment, control and
protection systems;
 The application of appropriate systems of work including: written instructions,
permits to work and other procedural systems for organising the work;
 DSEAR also requires the identification and marking of hazardous contents within
containers and pipes.
6.3 Zoning explosive atmospheres
In places where the risk assessment indicates that explosive atmospheres may occur
they must be classified by zoning on the basis of frequency and duration of the
occurrence of an explosive atmosphere.
a) Zones for explosive mixtures of gases, vapours or mists
Zone 0 – a place in which an explosive atmosphere is present frequently,
continuously or for long periods;
Zone 1 - a place in which an explosive atmosphere is likely to occur occasionally in
normal operation;
Page 7 of 26
Zone 2 - a place in which an explosive atmosphere is not likely to occur in normal
operation but, if it does, it will persist for a short time only.
b) Zones for combustible dusts
Zone 20 – a place in which an explosive atmosphere is present frequently,
continuously or for long periods;
Zone 21 - a place in which an explosive atmosphere is likely to occur occasionally in
normal operation;
Zone 22 - a place in which an explosive atmosphere is not likely to occur in normal
operation but, if it does, it will persist for a short time only.
The extent of the zoned area depends on a number of factors including:
 Release rates – the greater the potential release rate the larger the extent of the
zone;
 The Lower Explosion Limit (LEL) – the lower the LEL the greater the extent of the
zone;
 Ventilation – improved ventilation will reduce the extent of the zone;
 Relative density – gas or vapours significantly lighter than air will tend to move
upwards. If they are significantly heavier than air they will tend to accumulate at
ground level or in pits, trenches or lower levels;
 Other parameters – may include climatic conditions, topography etc;
 Liquid or process temperature – substances processed above their flash point
may give rise to hazardous areas if ignition sources are present;
 Formation of sprays and mists – substances which could be released as a mist or
spray may give rise to a hazardous area even if their flash point in liquid form is
high.
Detailed guidance on the classification and zoning of areas where potentially
explosive atmospheres may occur, and the selection of equipment for use in those
areas can be found at http://www.hse.gov.uk/fireandexplosion/atex.htm
6.3.1 Signage
Where necessary, areas classified into zones must be marked with a specified "EX"
sign at their points of entry. This is to warn persons that an explosive atmosphere
may be present so they can take all necessary precautions in relation to the risk.
This may include the marking of flammable storage cabinets, fume cupboards, etc.
6.3.2 Equipment suitability for explosive atmospheres
Unless the risk assessment indicates otherwise, in order to prevent sources of
ignition from equipment (fixed and portable) and protective systems used within
zoned areas, it must be designed and be suitable for that particular zone
classification (e.g. meeting the requirements of the Equipment and Protective
Systems Intended for Use in Potentially Explosive Atmospheres (EPS) Regulations
1996.
Page 8 of 26
Equipment already in use before 1 July 2003 can continue to be used indefinitely
provided the risk assessment shows it is safe to do so. A standardised marking
scheme is widely used to help identify equipment suitable for specific locations/zones
(see Appendix 2).
If the risk assessment indicates that electrostatic discharges could ignite an explosive
atmosphere, suitable measures to ensure the prevention of static discharge from
equipment must be implemented. Additionally employees working within zoned
areas should be provided with appropriate clothing, including footwear, sufficient to
control the ignition risk.
Prior to coming into operation for the first time, areas where explosive atmospheres
may be present should be verified as being safe by a person competent in the field of
explosion protection. Consideration must also be given to the particular risks at the
workplace and the adequacy of control measures put into place.
6.4 Arrangements to deal with accidents, incidents and emergencies
DSEAR requires the University to assess the likelihood and scale or magnitude of the
effects that may result from any foreseeable accident, incident or emergency related
to the presence of a dangerous substance and put in place arrangements
proportionate to the risks to protect employees (and others who are at the
workplace). As indicated by the risk assessment this may include:
 Suitable warning (including visual and audible alarms) and communication
systems;
 Escape facilities;
 Emergency procedures, providing information to employees and others on these
procedures;
 Equipment and clothing for essential personnel dealing with the incident;
 Practice drills;
 Liaison with Emergency Services as to what assistance can be provided.
Note: This requirement reinforces existing legislation e.g. the Management of Health
and Safety at Work Regulations 1999, the Control of Substances Hazardous to
Health Regulations 2002 and the Regulatory Reform (Fire Safety) Order 2005 and
therefore should not require any additional duties to those already be in place.
6.5 Information instruction and training
The University is required to provide employees and other people in the workplace
who might be at risk (e.g. students, contractors, etc and employee representatives)
with suitable and sufficient information, instruction and training proportionate to the
level and type of risk. This should include the precautions and actions they need to
take in order to safeguard themselves and others:
 Names of the substances in use and the extent of the risks they present;
 Access to any relevant material safety data sheet (MSDS);
 Information on the legislation that applies to the hazardous properties of the
substances;
 The significant findings of the risk assessment;
 The adopted control/mitigation measures, including methods of work, the reasons
for them, and how to use them correctly;
 Emergency procedures;
 Any other relevant information.
Page 9 of 26
DSEAR states that any training provided should include elements of both practice
and theory and be pitched appropriately. The objective is to ensure that persons can
work with dangerous substances without putting themselves or others at risk.
6.6 Identification of hazardous contents of containers and pipes
DSEAR requires the University to ensure all pipe work and any containers which hold
or transport hazardous substances be suitably marked in accordance with relevant
legislation (e.g. The Chemicals (Hazard Information and Packaging for Supply)
Regulations 2002, The Health and Safety (Safety Signs and Signals) Regulations
1996, etc).
DSEAR does not specify the means of identification and suitable could mean
labelling, use of colour coding or providing instruction and training. The most
appropriate means of identification will depend on the work activity, for instance, in
situations where the contents may change regularly (e.g. test tubes, flasks etc) it may
not be practical to use labelling. However, flammable substances being stored in
containers must be adequately labelled to reflect contents and associated hazards.
7.0 Summary of Responsibilities
In general, the majority of responsibilities under DSEAR, to assess the risk of fires
and explosions that may be caused by dangerous substances in the workplace
should already be addressed in general and/or activity specific risk assessments.
DSEAR merely builds upon existing legislative requirements under the Management
of Health and Safety at Work Regulations 1999, the Control of Substances
Hazardous to Health Regulations 2002, and the Regulatory Reform (Fire Safety)
Order 2005, etc.
The specific requirements under DSEAR are:

Regulation 5 - requirement to undertake suitable and sufficient assessment of
the risks arising from dangerous substances;

Regulation 6 - ensure the risks from dangerous substances are either
eliminated or reduced so far as is reasonably practicable;

Regulation 7 - requirement to classify areas where an explosive atmosphere
may occur;

Regulation 8 - requirement to make arrangements to deal with accidents,
incidents and emergences;

Regulation 9 - provision of information, instruction and training;

Regulation 10 - requirement to identify and mark containers and pipes
containing dangerous substances;

Regulation 11 - requirement for co-ordination in shared workplaces.

Schedule 1 - General safety measures;

Schedule 2 - Classification of places where an explosive atmosphere may
occur;

Schedule 3 - Criteria for the selection of equipment and protective equipment;

Schedule 4 - Warning signs;

Schedule 5 - Legislation covering the marking of pipes and containers.
Page 10 of 26
8.0 References
HSE. (2003). Dangerous Substances and Explosive Atmospheres. Dangerous
Substances and Explosive Atmospheres Regulations 2002. Approved Code of
Practice and guidance L138 .
HSE. (2003). Design of plant, equipment and workplaces.
Subst03.02.06002. Approved Code of Practice and guidance L134.
Dangerous
HSE. (2003). Storage of dangerous substances. Dangerous Substances and
Explosive Atmospheres Regulations 2002. Approved Code of Practice and guidance
L135.
HSE. (2003). Control and mitigation measures. Dangerous Substances and
Explosive Atmospheres Regulations 2002. Approved Code of Practice and guidance
L136
HSE. (2003). Safe maintenance, repair and cleaning procedures. Dangerous
Substances and Explosive Atmospheres Regulations 2002. Approved Code of
Practice and guidance L137
HSE. (2004). Safe Working with Flammable Substances L75
http://www.hse.gov.uk/pubns/indg227.pdf
HSE. (1998). HS(G)51 The Storage of Flammable Liquids in Containers
HSE. (2006). Guidance on the classification and zoning of areas where potentially
explosive atmospheres may occur, and the selection of equipment for use in those
areas. http://www.hse.gov.uk/fireandexplosion/atex.htm
HSE. (2000) HSE8(rev2): Take Care with Oxygen: Fire & explosion hazards in the
use of oxygen
HSE. (2000). INDG327. Take Care with acetylene
HSE. (2000). INDG308 The safe use of gas cylinders.
HSE. (1999). HSG129: Health & safety in engineering workshops
HSE. (1997). The safe use of compressed gasses in welding, flame cutting and
allied processes
HSE. (2000). INDG297; Safety in gas welding and similar processes
Norwich Union (2005). DSEAR. Training course manual.
Page 11 of 26
Appendix 1a. Example DSEAR Risk Assessment Oxyacetylene Welding
Risk Assessment For
School / Service
Assessment Undertaken By
Name
Assessment Reviewed
Name:
Location of Activity: Metalworking Workshop
Date:
Date:
Activity: Oxyacetylene Welding within designated and curtained off
welding booth and storage of gas cylinders.
Signed by Head of School /
Service or nominee
Acetylene (C2H2) Extremely flammable, can form explosive mixture
with air, flammability range 2.4-88 vol% in air. Lighter than air.
Oxygen (O2) Oxidant, strongly supports combustion, heavier than air.
REF:
Date
Significant hazards:
People who
are at risk:
Build up of an explosive
atmosphere with potential
for a confined vapour
cloud
explosion
from
accidental
release
of
acetylene
gas
and/or
enhanced fire/explosion
from release of oxygen to
atmosphere through:
Staff,
students
using
welding
booth /
workshop
 leaks in flexible hose,
joints, hose connections
or fittings
 faulty flashback arrestor
 faulty non-return valves
 flashback from blowpipe
Building
occupants
Existing controls, safety procedures etc.
Actions required for risks
which are not adequately
controlled
Remaining
level of risk:
high, med or
low
No oxyacetylene welding to be undertaken outside of DSEAR Awareness training
Low
booth;
for technical staff
Spare cylinders stored in designated external storage
facility, cylinders are transported in suitable cylinder
trolleys by staff trained in manual handling
techniques;
Compressed gas refresher
safety training
Emergency
Accidental
Release Procedures
Cylinder trolleys used to hold chained cylinders whilst Formal written procedure
in use;
for Oxyacetylene Welding
Cylinders located away from all sources of heat and Pre-use
equipment
flammable materials (>3m);
procedure checklist
Regulators, gauges, hoses, connections, hose
assemblies, blowpipes, safety devices, etc compliant Use of proprietary leak
with all relevant British Standards;
detecting spray or solution
Regulators and flame arrestors serviced or replaced suitable for use with oxy /
every 5 years, and inspected annually by a fuel systems.
 damage to cylinders /
regulator through impact
/ handling
 direct heating of
cylinders leading to
exothermic reaction
 tampering
 reaction of acetylene
with other
chemicals/materials
 failure to light gas torch
competent person and inspection recorded;
Air monitoring by SHE
Maintenance and examinations of equipment by Section whilst equipment is
competent person;
in use.
Pre-use equipment check;
Dedicated LEV system for welding equipment,
subjected to annual inspection/testing in accordance
with statutory requirements;
LEV system must be used when welding equipment
in use, monitored/enforced by staff;
Workshop induction / training in use of equipment /
LEV system operation for students;
Acetylene equipment must not contain copper or
come into contact with silver or mercury which could
form explosive acetylides;
With LEV in operation hoses are purged of any
flammable mixtures of gases before blowpipe is lit;
Equipment must not be used above manufacturer’s
recommended pressures;
Hoses to be kept clear of sharp edges and abrasive
surfaces, metal splatter to hoses to be avoided;
Correct gas pressures and nozzle size for the job to
be used;
Build up of an explosive
atmosphere within the
LEV ducting
Staff,
students
using
welding
booth /
workshop
Building
Air monitoring available upon request by SHE
Section.
Specifically designed LEV system, filters changed in DSEAR Awareness training
accordance with manufacturers recommendations;
for technical staff
Workshop used for metals only - no other materials /
substances are permitted to be extracted using the Compressed gas refresher
safety training
system (e.g. plastics, solvents, etc).
LEV subjected to annual inspection/testing in Air monitoring by SHE
Section whilst equipment is
accordance with statutory requirements.
in use.
Page 13 of 26
Low
occupants
Ignition sources - beyond
the naked flame used to
light / emitted from
blowtorch in normal
operation
Staff,
students
using
welding
booth /
workshop
Building
occupants
No alterations to the LEV permitted without
consultation from FM Development & Maintenance
Section / specialised LEV contractor.
No record or evidence of any explosion with the LEV
since its installation.
Smoking prohibited throughout the entire building
Low
Welding area surrounded by curtain screens - provide
direct protection from abrasive wheel grinding sparks
Earthing to LEV ducting to prevent static build up;
All portable electric hand tools PAT certificated
General inspections by technical staff /Building
Manager
University Security procedures to prevent malicious
ignition/arson
Fire - general
Staff,
students
using
welding
booth /
workshop
Building
occupants
UCLAN fault / maintenance reporting procedures.
Remove all possible combustible material from Emergency
Accidental
welding area, protection for any combustible Release Procedures
materials that cannot be moved from close contact
with flame, heat, sparks or hot slag.
Oil/grease must not come into contact with oxygen
valves or cylinder fittings.
Fire detection/alarm system, fire escape route, fire
extinguishers, fire doors, trained fire marshals,
signage, fire safety and evacuation procedures.
Building Fire Risk Assessment
No flammable substances stored within the welding
area. Dedicated flammable storage cabinet
First Aid, Accident/Near-miss Reporting Procedures
Good housekeeping/cleaning practices/procedures
General inspections by technical staff /Building
Page 14 of 26
Low
Manager
Cleaning and
maintenance of
equipment
Staff,
students
using
welding
equipment
Building
occupants
Contractors
Build up of an explosive Staff,
atmosphere within the gas students
cylinder store.
Contractors
Building
occupants
UCLAN fault/maintenance reporting procedures.
Oils/greases prohibited for lubrication of oxygen Maintenance and record
equipment.
keeping procedure
Low
Only replacement parts specifically designed for Compressed gas refresher
oxygen use permitted
safety training
LEV annually inspected/tested
specialised contractor
by
competent
Maintenance and examinations of equipment by
competent person.
Information provided to contractor re-risk of explosion
to inform their specific maintenance risk assessment.
Natural ventilation, bottles shielded from direct Gas cylinder store requires
sunlight.
Class 2 Zone (demarcation
and signage)
No other activities to be undertaken in cylinder store;
Low
Gas bottles securely chained whilst in store
Security – authorised persons only, key control
access
Signage
General inspections by trained technical staff
Ignition sources within the
gas cylinder store
Staff,
students
Contractors
Building
occupants
UCLAN fault / maintenance reporting procedures.
Cylinder store located away from all sources of heat
and flammable materials (>3m);
No electrical equipment permitted within the store
other than intrinsically safe gas detection monitors,
no naked flames, surfaces or sources of mechanical
energy;
General inspections by technical staff
University Security procedure
UCLAN fault / maintenance reporting procedures.
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Appendix 1b. Example DSEAR Risk Assessment Paint Spraying Workshop
Risk Assessment For
School / Service:
Assessment Undertaken By
Name
Assessment Reviewed
Name:
Location of Activity: Paint Spraying Workshop
Activity: Infrequent paint spraying using compressed air and aerosol
cans of various small items using small quantities (300-500ml) of
acrylic/cellulose based paints within three purpose built spray booths,
with extraction via a dedicated LEV system.
Date:
Signed by Head of School /
Service or nominee
Date:
Spray booths are now little used (1-2 times per month) compared with
their original design criteria. No report or evidence of fire or explosion
within the room or LEV system since its installation and
commissioning.
REF:
Date
Significant hazards:
People who
are at risk:
Build up of an explosive
atmosphere associated
with the spraying of
paints within the booths.
Staff, students
using spray
booth
Other building
occupants
Existing controls, safety procedures etc.
Actions required for risks
which are not adequately
controlled
Three adjacent purpose built spray booths with Use of water based paints
extraction via a dedicated LEV system, whenever reasonably
subjected to annual inspection/testing in practicable
accordance with statutory requirements;
Class 1 Zoning of booth
LEV system must be used when spraying interior (demarcation and
activities
are
taking
place,
use signage)
monitored/enforced by staff;
Class 2 Zoning of workshop
Paints/thinners stored in dedicated and locked and flammable storage
flammable substances storage cabinet access cabinet (demarcation and
via staff only. Lids kept on cans and containers signage)
closed to prevent vapour escape;
Signage stating LEV must be
Workshop induction / training in use of spray
equipment/ LEV system operation;
used when spraying
All unnecessary equipment to be kept out of
booths whilst spraying undertaken to minimise
DSEAR Awareness training
for technical staff
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Remaining level
of risk: high,
med or low
air flow disturbance;
Air monitoring by SHE Section
whilst equipment is in use.
No spraying to be undertaken out side of the
spray booths;
Maintenance as required and annual
examinations of equipment by competent
person;
Build up of an explosive
atmosphere within the
LEV ducting
Staff, students
using spray
booth
Other building
occupants
Maintenance
contractors
Ignition sources
Staff, students
using spray
booth
Other building
occupants
Maintenance
contractors
Air monitoring available upon request by SHE
Section.
LEV system specifically designed for paint Air monitoring by SHE Section
spraying operations;
whilst equipment is in use.
Subjected to annual inspection/testing
accordance with statutory requirements;
LEV filters changed in accordance
manufacturers recommendations;
in
with
No alterations to the LEV permitted without
consultation from FM Development &
Maintenance Section / specialised LEV
contractor.
No record or evidence of any explosion with
the LEV since its installation;
Smoking prohibited throughout the entire
building;
Lighting, switches and sockets flame proof by Annual testing of electrical
system
design and appropriate for Class 2 area;
No other electrical equipment used within the
workshop, no hot-work (without implementation
of FM permit to work system), no naked
flames, surfaces or sources of mechanical or
chemical energy;
Earthing to LEV ducting to prevent static build
up;
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General inspections by technical staff /Building
Manager;
Fire
Staff, students
using spray
booth
Other building
occupants
Maintenance
contractors
UCLAN fault / maintenance reporting
procedures.
Fire detection/alarm system, fire escape route,
fire extinguishers, fire doors, trained fire
marshals, signage, fire safety and evacuation
procedures;
Building Fire Risk Assessment;
No flammable substances stored outside of
flammable storage cabinet;
First Aid, Accident/Near-miss Reporting
Procedures;
Good housekeeping/cleaning
practices/procedures;
General inspections by technical staff /Building
Manager;
Spillage of paint /
thinners whilst mixing
Cleaning and
maintenance of
equipment
Staff
UCLAN fault/maintenance reporting
procedures.
Paints only mixed by technical staff;
Spillage procedures
Paints/thinners mixed in spray booths with LEV
in operation to extract vapours and decanted
over a tray to minimise spillage;
Staff, students
Maintenance
contractors
Staff,
Contaminated clean-up materials to be kept in
lidded metal bin for disposal through SHE
Section.
Equipment maintained by competent person;
Workshop induction / training in use of spray
equipment/LEV system operation;
LEV annually inspected/tested by competent
specialised contractor;
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Maintenance / cleaning
procedures
LEV filters changed in accordance with
manufacturers recommendations.
Information provided to contractor re-risk of
flammable atmosphere explosion to inform
their specific maintenance risk assessment.
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Appendix 1c. Example DSEAR Risk Assessment Woodworking Workshop
Risk Assessment For
School / Service
Location of Activity: Woodworking Workshop
Assessment Undertaken By
Name
Date:
Activity: Wood working operations producing fine wood dusts
(typically softwood, hard wood, MDF and some plastics and foam)
potential of a dust explosion.
REF:
Signed by Head of School /
Service or nominee
Assessment Reviewed
Name:
Date:
Date
Significant hazards:
People who
are at risk:
Existing controls, safety procedures etc.
Build up of an explosive
atmosphere associated
with accumulations of
wood dust becoming
airborne
Staff, students
using
workshop
Dedicated LEV system for all relevant
woodworking equipment, subjected to annual DSEAR
Awareness
inspection/testing in accordance with statutory training for technical staff
requirements;
level
cleaning
Weekly checks to ensure LEV system is High
regime
to
beams,
heating
operating without dust leaks;
pipes, light fittings, etc to
LEV system must be used when relevant reduce risk of secondary
equipment
is
being
used,
use dust explosion.
monitored/enforced by staff;
Other building
occupants
Actions required for
risks which are not
adequately controlled
Remaining level of
risk: high, med or
low
Low
Workshop ‘low level’ cleaning procedures,
sweeping only permitted on equipment surfaces
into extraction unit, no accumulations of wood
dusts permitted;
Workshop induction / training in use of
equipment / LEV system operation.
Build up of an explosive
atmosphere within the
Staff, students
using
Air monitoring available upon request by SHE
Section.
LEV system specifically designed for wood dust
removal, filters, collection drum emptied/cleaned/
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LEV ducting
Ignition sources
workshop
changed in accordance with manufacturers
recommendations;
Other building
occupants
Workshop used predominantly for wood, small
quantities of plastic and foam also cut no other
materials/substances are permitted to be
extracted using the system (e.g. solvents);
LEV subjected to annual inspection/testing in
accordance with statutory requirements.
Staff, students
using
workshop
Other building
occupants
No alterations to the LEV permitted without
consultation
from
FM
Development
&
Maintenance Section / specialised LEV
contractor.
Smoking prohibited throughout the entire
building;
Low
Earthing to any plastic LEV ducting to prevent
static build up;
No hot-work (without implementation of FM
permit to work system), no naked flames,
surfaces or sources of mechanical or chemical
energy.
All portable electric hand tools PAT certificated;
General inspections by technical staff /Building
Manager;
Fire
Staff, students
using
workshop
Other building
occupants
UCLAN fault / maintenance reporting
procedures.
Fire detection/alarm system, fire escape route,
fire extinguishers, fire doors, trained fire
marshals, signage, fire safety and evacuation
procedures.
Building Fire Risk Assessment;
No flammable substances stored within the
workshop;
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First Aid, Accident/Near-miss Reporting
Procedures;
Good housekeeping/cleaning practices /
procedures;
General inspections by technical staff /Building
Manager;
Cleaning and
maintenance of
equipment
Staff, students
using
workshop
UCLAN fault/maintenance reporting procedures.
LEV annually inspected/tested by competent
specialised contractor, filters cleaned/changed in
accordance with manufacturers
recommendations.
Contractors
Careful dust control during filter changes;
Information provided to contractor re-risk of dust
explosion to inform their specific maintenance
risk assessment.;
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Appendix 2 Practical Application of DSEAR
Consideration of the following factors will help to ensure that risks from fire and explosion are
eliminated or reduced so far as is reasonably practicable:
Flammable liquids (e.g. solvents, petrol etc)
Flammable liquids can give off large volumes of flammable vapours at room temperature,
which when mixed with air, can ignite. Spilled liquids can flow a long way to an ignition
source if not contained and then flash back to the source of the spill. Clothing contaminated
with flammable liquids represent a serious risk of injury if ignited:
 Can you exchange the flammable substance for a less flammable one or even eliminate
its use altogether;
 Ensure there is good ventilation where flammable liquids are used/stored, as this will
mean that any vapours given off from a spill, leak, or release from any process, will be
rapidly dispersed;
 Keep the volume of solvents in workshops and laboratories to a working minimum;
 Store flammable liquids in a separate storage area, or in a purpose-made bin or cabinet
that is labelled with the ‘Ex’ sign;
 Larger quantities of flammable liquids should be stored in the dedicated University
facilities;
 Sources of ignition must be identified and where possible disconnected or removed to
prevent sparks when solvents are being poured. Electrical items, which are not in use,
must be switched off and the plug disconnected at the socket.
 Keep containers closed when not in use. If possible, use safety containers which have
self-closing lids;
 Dispense liquids over a tray and keep some non-flammable absorbent material handy to
mop up spills;
 If you are dispensing petrol into equipment, ensure it is turned off, if it has hot surfaces in
close proximity to the filling point ensure the surfaces have cooled sufficiently and there
are no other sources of ignition (e.g. naked flames, smoking, sparks, etc) before
commencing filling;
 Dispose of contaminated materials safely through the SHE Section, remember material
soaked in many flammable substances can self ignite if not stored correctly.
Flammable dusts
Finely divided flammable dusts, including wood dusts, dispersed in the atmosphere can, if
ignited, explode violently and cause considerable damage. Even layers, deposits and heaps
of dust should be considered as any other source which could form an explosive
atmosphere. When handling flammable dusts remember the following:
 Keep equipment dust-tight;
 As far as practicable, ensure working areas are kept dust-free by regular cleaning, and
vacuuming;
 Ensure dust handling equipment such as LEV systems are properly maintained by a
competent person.
Flammable gases
Gases in cylinders are often stored at very high pressures therefore any uncontrolled release
can be extremely dangerous, even a small amount of released gas can fill a large area with a
potentially explosive mixture. This is particularly true of liquefied gases such as LPG. The
following points need to be considered:
 Can you exchange the flammable gas for a less flammable one or even eliminate its use
altogether;
 Ensure there is good ventilation where flammable gases are used/stored, as this will
mean that any vapours given off from a spill, leak, or release from any process, will be
rapidly dispersed;
 Stored cylinders need to be suitably restrained and their valves protected from impact
damage;
 Are the valves, fittings and hoses suitable for the gases used, always check the suppliers’
instructions and ensure they are fitted correctly to the equipment by a competent person;
 Always protect hoses from potential causes of damage that could cut, abrade or weaken
them. Examine them regularly and replace them if they show signs of damage or wear
must be reported immediately as they could give rise to a leak.
 Never use oxygen instead of compressed air or use it to ‘sweeten’ the air in a working
area or a confined space and never use grease or oil on equipment containing oxygen.
Reactive chemicals
Some products contain chemicals, such as organic peroxides, which can explode if they are
not stored and handled correctly. Other substances can react vigorously with incompatible
materials or contaminants, e.g. oxidising chemicals can cause flammable materials to ignite,
and some substances, such as sodium, react violently with water and can ignite. The
following points need to be considered:
 Ensure storage and process temperatures are carefully controlled to prevent dangerous
decomposition or reaction;
 Check labels and safety data sheets for physical properties and incompatibility with other
materials.
Page 24 of 26
Appendix 3 Suitability of Equipment for Hazardous Zones
Once a potentially hazardous area has a zone classification, appropriate electrical equipment
must be selected, consideration should be given to the following:




Risk of an ignition source being present;
Ease of ignition of the potentially explosive atmosphere by spark;
The auto ignition temperature of the flammable material;
Constructional features of the apparatus.
There are several different methods of providing explosion protection for electrical
equipment
Zone
0
0
International
Symbol
1a
s
Type of Protection
1
1
1
1
1
1
1
1
1
lb
d
p
e
o
q
s
m
Any type of protection suitable for zone 0
intrinsic safety – type b
flameproof enclosure
pressurisation
increased safety
oil immersion
powder/sand filled apparatus
special protection
encapsulation
2
2
n
Any type of protection suitable for zones 0 and 1
type N
intrinsic safety – type a
special protection – certified zone 0
Gas Groups
For gases apparatus is divided into two main groups, Group I for mines and Group II for all
other surface industrial applications.
Group II is further subdivided for flameproof and
intrinsically safe apparatus because both can produce sparks. The sub divisions are for
gasses/vapours with similar spark ignition characteristics:
Group IIA 150 different gases and vapours (e.g. propane and methane)
Group IIB 36 different gases and vapours (e.g. ethylene and methanol)
Group IIC Hydrogen, acetylene, ethyl nitrate and carbon disulphate
Equipment suitable for IIC can be used for IIA or IIB gases, equipment suitable for IIB can be
used for IIA gases, equipment suitable for IIA can only be used for IIA gases.
Surface Temperature
The surface temperature of the equipment must be lower than the auto-ignition temperature
for the gas or vapour concerned. Equipment is rated into six categories depending on
maximum surface temperature.
Page 25 of 26
Temperature
marking
T1
T2
T3
T4
T5
T6
Max surface temperature Auto-ignition
temp
o
C
gas/vapour
450
>450
300
>300
200
>200
135
>135
100
>100
85
>85
of
Equipment Testing and Marking
All explosion protected equipment must be submitted to an approved body for explosion
testing and type approval. Equipment which has been approved will bear the CE mark, the
name of the approved body and its mark, the certificate of conformance and a code denoting
the equipments rating, an example code is given below:
EEx
ia
Cenelec approved
IIC
T6
Suitable for gas Group
IIC (e.g. hydrogen)
Approved for hazardous
atmospheres
Intrinsically safe type a
(suitable for Zone 0)
Temperature classification
(Max surface temp 85 0C)
Mandatory Requirements for New Equipment from June 2003
Under the requirements of the Equipment and Protective Systems Intended for Use in
Potentially Explosive Atmosphere Regulations 1996, equipment will have to conform to the
following standards:
For Hazardous Area Classification
Zone 0
Zone 1
Zone 2
Zone 20
Zone 21
Zone 22
Use Equipment Rated
1
1 or 2
1, 2 or 3
1
1 or 2
1, 2 or 3
Under the new requirements equipment markings will appear as shown below:
EX
1
2
3
G or D
I
II
IIA
IIB
IIC
T1- T6
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