Section 1: Letter to licensee

Dangerous substances and explosives atmospheres regulations 2002 

An Important Communication to Licensees

Dear Licensee 

Your petroleum licence is now comprised of fewer conditions than previously. The reason behind the reduction in licence conditions is the implementation of the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) in December 2002. DSEAR is a piece of modern health and safety legislation that places responsibility upon employers, and in view of this, the Authority renders the prescriptive conditions of a Petroleum Licence unnecessary. The purpose of this document is to advise licensees and site operators of their duties and responsibilities under DSEAR. It is not a complete statement of requirements and is intended only as a guide. The information it contains is believed to be correct: but the document is not a substitute for appropriate legal advice. 

It is understood that licensees will require time to familiarise themselves with the enclosed advice, perform the risk assessment and record it in a suitable format. 

What is DSEAR?

DSEAR is a set of regulations issued under the Health and Safety at Work Etc. Act 1974, which implement the requirements of the Chemical Agents and Explosive Atmospheres Directives of the European Community. 

The purpose of these regulations is to control the risk of fire and explosion in the workplace. 

Dangerous substances

A dangerous is a substance that could cause harm to people from fire or explosion due to its properties or use. This would include (among other things) petrol, liquefied petroleum gas (LPG), liquefied natural gas (LNG) or hydrogen. 

Explosive atmosphere

An explosive atmosphere is an accumulation of flammable gas, mist, dust or vapour combined with air.

Where does DSEAR apply?

DSEAR applies at all workplaces where a dangerous substance is, or could be, present and there is a consequent risk to employees or others. Hence it will apply at any workplace where petroleum spirit is kept, and on any premises where petrol is dispensed from a storage tank into the fuel tank of a vehicle. It is enforced by this Authority within the area of Dorset Council. 

The employer’s responsibilities 

The employer is required to:

  • carry out a risk assessment of any activity involving a dangerous substance – on a petrol filling station these activities would typically involve fuel deliveries, dispensing, repair, modification and maintenance
  • provide measures to eliminate or reduce risks, this could be by means of procedures to be followed along with maintenance and installation of suitable equipment
  • provide equipment and procedures to deal with any incidents that may occur on the forecourt due to fire or explosion associated with fuel
  • identify hazard zones on site where an explosive atmosphere may occur during certain activities

The employer may be deemed to be the site operator and the person/company responsible for the equipment or the fuel on site, if they differ. 

Contractors on site

When there is a contractor working on site, either their employer, or themselves if self-employed, and the employers responsible for the petrol filling station, have responsibilities under DSEAR. 

Each employer has duties to their own employees and to the employees of any other employer involved on the premises. Employers should co-operate. 

The risk assessment

The recommended procedure for carrying out a risk assessment is to follow the 5 steps as published by the Health & Safety Executive. They are:

  1. Identify the hazards – such as fuel, sources of ignition, etc.
  2. Identify those at risk – this would include members of the public who may be affected by an accident, they could be neighbouring buildings, in tunnels, schools.
  3. Evaluate the risk – access the risk and decide upon any control measures that would reduce them to an acceptable level.
  4. Record finding and actions taken – the findings should show whether or not the existing control measures are adequate, and if not, what further action is required to reduce the risks to an acceptable level.
  5. Review and revise the risk assessment – it is important that if any changes are proposed the risk assessment be recognised to access whether or not there is any change to the level of risk arising from the changes.

DSEAR lays down what is required of the risk assessment and how it should be carried out. The criteria to be taken into account when carrying out the risk assessment include the following: 

  • the hazardous properties of the substances that are kept or used – these will be found on the Safety Data Sheets for the particular fuels that are kept
  • the methods of use and storage – this would include type and age of equipment used and systems in place to prevent or contain leaks or spillage
  • the possibility of a hazardous explosive atmosphere existing during any activities on the forecourt
  • all potential ignition sources

If there are 5 or more employees, including the site operator or contractors, then the findings of the risk assessment have to be recorded in writing. The document should contain (among other things) the following information: 

  • the measures that have been put into place to eliminate or reduce the risk of fire and explosion
  • information to show that the workplace and equipment will be safe during operation and maintenance
  • arrangements that are in place to deal with incidents, i.e. the emergency plan
  • the measures that have been taken to train and inform all employees in fire and explosion related safety matters
  • details of the hazard zones on the forecourt

Consult DSEAR itself for a full list.

The control measures identified by the risk assessment should be designed to achieve the aims set down in DSEAR in the following order. 

  1. Reduce quantities of hazardous substances to a minimum – clearly this is difficult to apply to a petrol filling station where the purpose is to keep these substances for sale. 
  2. Avoid or minimise release – for instance leak prevention, leak detection and control of spillage. 
  3. Control releases at source. 
  4. Prevent the formation of explosive atmospheres. 
  5. Contain or remove any releases to a safe place – such as a forecourt separator or ventilation. 
  6. Avoid ignition sources. 
  7. Avoid adverse conditions. 
  8. Keep incompatible substances apart. 

Required arrangements 

Each petrol filling station should have an Emergency Plan in place detailing actions to be followed in the case of any foreseeable incident that may occur. All staff should be aware of the Emergency Plan and their responsibilities under it. There should be a procedure for notifying the relevant emergency services and for evacuating the premises. Practice drills should be carried out on a regular basis to ensure that all staff are familiar with the process. 


All staff must be trained according to the requirements of DSEAR. They should be made aware of the dangerous substances that are likely to be present and they should know the risks that these substances present. Up to date and detailed records of all relevant training should be maintained and used as supporting evidence to the findings of your risk assessment.

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Section 2: Guidance on powers of inspection

DSEAR is supported by a series of Approved Codes of Practice (ACoP), some of which are referred to in this guidance document. You should be aware of the special legal status of ACoPs. 

Who enforces the Petrol Safety Legislation at Petrol Filling Stations? 

The local Petroleum Enforcement Authority (PEA) appoints Petroleum Inspectors to enforce the Petroleum (Consolidation) Regulations 2014 and the Dangerous Substances & Explosive Atmospheres Regulations 2002 at premises falling within the definition of a ‘petrol filling station’. Dorset Council’s Trading Standards Service act as the PEA. 

Note: All other health and safety legislation, eg the Health & Safety at Work etc Act 1974, the Management of Health and Safety at Work Regulations 1999 and the Electricity at Work Regulations 1996, are enforced by your council’s Environmental Health Officer and in some cases Inspectors from the Health & Safety Executive. 

What will Petroleum Inspectors do? 

Their job is to ensure that you are doing what the law requires. They will check to see how you manage fire and explosion risks. They will provide advice, may require improvements to be made, and will enforce the law when needed. They will also investigate incidents and complaints in connection with the petrol installation. 

For new petrol stations or material changes to existing ones, Petroleum Inspectors will decide whether the petroleum licensing authority should grant a petroleum licence, and discuss any further action you may need to take to ensure safety. Petroleum Inspectors will also liaise with the local Planning Department. 

Once a petrol station is operational (ie storing and dispensing petrol), inspectors may visit unannounced. You are entitled to see their identification before letting them look around. Remember they are also there to give help and advice. You may want to talk to an Inspector before carrying out any planned changes to your site. 

If Inspectors find problems they will deal with you in a reasonable and fair way. Inspectors will explain to you or your representative anything you need to do to address the problems. 

What powers do Inspectors have? 

Inspectors have extensive powers, which include the right to enter your premises, talk to employees and safety representatives and take photographs and samples. If they consider there is a problem at a petrol station, they can: 

  • give advice or guidance on how to address the problem, this will always be confirmed by the Inspector in writing
  • issue a notice which requires improvements to be made where the law has been breached
  • issue a Prohibition Notice which stops a process or the use of dangerous equipment where a risk of serious personal injury exists; or
  • recommend to the petroleum licensing authority that an application to renew the petroleum licence is refused 

Before an inspector issues an improvement or prohibition notice, he will explain and discuss the item(s) of non-compliance with yourself or your representative. If you receive an Improvement or Prohibition Notice you have the right to appeal to an industrial tribunal. 

Inspectors can prosecute a business or, under certain circumstances, an individual for breaking health and safety law, but they will take your attitude, management and safety record into account before taking such action. 

What rights do I have? 

If your application for the grant or renewal of a petroleum licence is refused or if you are aggrieved at any condition attached to your petroleum licence, you can appeal to the Secretary of State at the Department of Work & Pensions at Health and Safety Sponsorship Division, 2 Floor, The Adelphi, 1-11 John Adams Street, London, WC2N 6HT.

If an Inspector tells you to do something, he/she will always confirm in writing what needs to be done and give a time period for the work to be completed.

When an inspector issues an Improvement Notice or a Prohibition Notice, you will be told in writing about your right of appeal to an industrial tribunal and be given an appeal form. You will also be given a leaflet explaining:

  1. How to appeal.
  2. Where and within what time period an appeal may be brought.
  3. That an appeal may be brought on any grounds; and 
  4. That any action required by an Improvement Notice is suspended while the appeal is pending.

If you are not satisfied with the way you have been treated, you can take the matter up with the inspector’s manager, whose name should be on all letters from the Authority. As with any health and safety inspector, all complaints about Petroleum Inspectors will be investigated and the outcome of the investigation made known to you.

Further details can be found in the Health and Safety Commission’s free publication, ‘What to Expect When a Health and Safety Inspector Calls’. 

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Section 3: What is risk assessment?

For the purposes of this document, risk assessment means a careful examination of how petrol could cause a fire and explosion. You do not have to remove the risk, in fact it is not possible to have ‘zero’ risk, but you must make sure it is as low as is reasonably practicable. 

Do I have to carry out a risk assessment? 

Under DSEAR, employers (including self-employed) must assess the risks from activities involving a dangerous substance (petrol) to employees and anyone else, such as members of the public. The significant findings of the assessment must be recorded if 5 or more persons are employed. Apart from contributing to the overall safety of the petrol station, this makes good sense and business. DSEAR also requires risk assessments to be reviewed as circumstances change. 

Do all petrol stations have to take the same safety precautions? 

No, the chance of an incident and its consequences vary between sites. 

Similarly, the action needed to prevent incidents will vary. Fire and explosion risks at petrol stations can be managed by: 

  1. Engineering controls/physical safeguards (also known as hardware), such as the installation of an overfill prevention device.
  2. Management controls, which minimise risk by using systems of work – for example at a site where a tanker has to manoeuvre on site, a system of supervision will reduce the risk of collision and possible spill; or 
  3. Commonly, a combination of both engineering and management controls. 

Reduction of risk by engineering controls or physical safeguards is a particularly effective way of ensuring people’s safety because these measures are always present and less likely to go wrong. However the time, trouble, financial cost and physical difficulty of installing engineering controls may mean that it is only reasonably practicable to introduce them when a new site is being built or an existing site is being materially changed. 

Bear in mind that future technological change may result in cheaper engineering controls. Such controls, although previously not reasonably practicable on financial grounds, may then become an option at your existing site. 

New sites 

The employer’s obligations under DSEAR (Regulation 6(8), Schedule 1 (1)) include ensuring that the workplace is designed, constructed and maintained so as to reduce risk. 

When a site is being designed and constructed, it should be possible to build-in engineering controls so that less reliance is placed on management controls and systems of work. For example, installing double skin tanks with interstitial leak monitoring, and locating the fill points so that a delivery tanker will be able to enter the site, unload, and leave without having to reverse. 

Existing sites 

If you have assessed the risks and decided that your current controls adequately ensure people’s safety, then you might not need to introduce any further measure. However, if you conclude that current controls are inadequate, you must introduce further measures. If the risk is low, the overall costs of introducing engineering controls might be grossly disproportionate, and effective management controls might be enough. However, if the risk is high, you may need to consider engineering controls, regardless of the overall cost. Remember that your ability to pay for additional measures is not a deciding factor as to whether they should be introduced.

For example, if a tanker has to reverse or manoeuvre onto or within a site to correctly position itself at the fill points, one or more measures may be necessary to reduce the risk of collision, which could lead to a spill of petrol. You would need to look at the relative costs and the degrees of control each option provides. The options could include: 

  • relocating the fill points or obstructions and obstacles (engineering control)
  • creating new entry points to the site to provide better access (engineering control)
  • closing the site whilst the tanker is on the site (management control – system of work)
  • arranging for deliveries to be made during quiet periods when fewer people are on or around the site (management control); or 
  • arranging for a competent member of staff to help the driver manoeuvre the tanker safely (management control – system of work)

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Section 4: Suggested pro forma for assessing the risks and control measures which should be implemented

Over the next few pages you will find a generic format for a suggested risk assessment. It is not intended that you will complete the actual document provided. However, the layout and the suggested headings and control measures contained within will enable you to consider the measures you have in place at your site and to perform and complete a similar assessment that accurately reflects the working practices at your site.

Table 1 - Controlling the risks from off-loading and venting

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Section 5

Assessing the risks - Storage

Firstly, consider the age and design of the storage tanks and then look at the leak detection methods you currently use. You will need to decide whether these precautions are enough to detect leaks, or if you need to do more. Table 2 shows one way you could go through this process. The control measures column gives some example precautions that could be taken there may well be alternatives. Some measures are most appropriate to new sites or those being refurbished. For older sites the cost could be disproportionate to the risk. Remember that you must provide sufficient control measures to keep the risk. 

Table 2 - Controlling the Risks from Storage

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Section 6

Assessing the risks - Pipework

Consider the age and design of your pipework. Then look at the leak detection methods you currently use. You will need to decide whether these precautions are enough to detect leaks or if you need to do more. Table 3 shows one way you could go through this process. The control measures column gives some example precautions that could be taken there may well be alternatives. Also some measures are more appropriate to new sites or those being refurbished than older, existing sites, where the cost of them could be disproportionate to the risk. Remember that you must provide sufficient control measures to keep the risk to people’s safety as low as is reasonably practicable. 

Table 3 Controlling the Risks from Pipework

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Section 7 - Dispensing

When you assess the risks associated with dispensing operations you will need to take into account the way you operate your site. Consider how the equipment is operated and identify how spills could occur. Then consider the possible ways to prevent each event, and measures to mitigate if it does happen. You will need to decide whether the precautions you have in place are sufficient to control the risk. 

Table 4 shows one way you could go through this process. The control measures column gives some examples of the precautions that could be taken; there may well be alternatives. Also, some measures are more appropriate to new sites or those being refurbished than older existing sites, where the cost of them could be disproportionate to the risk. Remember that you must provide sufficient control measures to keep the risk to people’s safety as low as is reasonably practicable. 

Table 4 - Controlling the Risks from Dispensing

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Section 8: Portable petrol containers - Wetstock control

The Conditions of Petroleum Licence allows petrol to be dispensed into a single demountable petrol tank, not exceeding 27 litres, for use on a motor boat or similar vessel, or into a portable metal container not exceeding 23 litres or into portable (approved) plastic containers not exceeding 5 litres.

Portable containers must be:

  • suitable for the purpose of storing petrol
  • suitably labelled to identify the highly flammable nature of the contents
  • constructed and maintained so that they are reasonably secure against breakage and leakage (of petrol and vapour); and fitted with a secure closure, ie a screw cap

Wetstock control for petrol filling stations 

Many petrol filling station operators rely on a manual petrol stock reconciliation system to detect leaks from the storage tanks and pipework. The basic idea is that by finding how much petrol has come out of a tank through the dispensers (by checking the totaliser readings, for example) and taking into account how much has been put into the tank, you can calculate how much should be left in the tank. If you then measure how much petrol actually is in the tank you know if there has been a loss or gain that could indicate a leak.

This method of leak detection relies on consistent measurements of the tank contents, the accuracy of the measurements, and knowledge of the pattern of apparent losses and gains for your site. 

A lot of sites still use dipsticks or pump-up gauges to measure the contents of tanks. Pump-up gauges and dipsticks can only be read to a certain accuracy, not usually better than 50 to 100 litres either way. The readings are still useful because over a period of time they can be analysed and in some cases very small leaks can be detected by using special methods. Even without specialist analysis the readings can be sufficient to detect leaks before a lot of petrol has been lost. 

Stock loses are to be expected due to evaporation, shrinkage and the displacement of vapour during the road tanker unloading process. Typically, an average stock loss of some 0.2% to 0.3% can be expected. However, at some sites average stock losses can be as high as 0.5% or 0.6%. Although most sites tend to experience stock losses, occasional stock gains can occur. 


  1. If vapour recovery system has been fitted then dipsticks and pump up gauges can become unreliable and it can be practically impossible to detect leaks. You should seek advice from your Petroleum Inspector if you are experiencing problems with stock measurements.
  2. For the purposes of detecting a leak, it is essential that the quantities of petrol delivered, stored and dispensed are accurately monitored and recorded on a daily basis.

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Section 9: References

Staff should be informed of the details of the legislation that applies to them and they should be made fully aware of the significant findings of the risk assessment. 


Dangerous Substances and Explosive Atmospheres Regulations 2002

S1 2002/2/2776 HMSO

Fire and Explosion – How Safe is Your Workplace

INDG370 HSE Books

Five steps to risk assessment

INDG163(REV1) HSE Books ISBN 0 7176 0695 3

Unloading Petrol From Road Tankers – Approved Code of Practice and Guidance

L133 HSE Books ISBN 0717621979 

This document outlines responsibilities of site operators and tanker drivers during deliveries of petrol filling station (May 2003) 

Fire Safety – An Employer’s Guide 

HSE Books ISBN 0 1134 1229 0

Design of Plant, Equipment and Workplaces – Approved Code of Practice

L134 HSE Books ISBN 0 7176 2199 5

This document outlines responsibilities of plant and equipment used in the workplace (October 2003) 

Storage of Dangerous Substances

L135 HSE Books ISBN 0 7176 2200 2

This document outlines the responsibilities of fuel storage (October 2003) 

Control and Mitigation Measures

L136 HSE Books ISBN 07176 2201

This document outlines the responsibilities to eliminate, control or reduce risks from dangerous substances in the workplace (October 2003) 

Safe Maintenance, Repair and Cleaning Procedures

L137 HSE Books ISBN 0 7176 2202 9

Gives guidance on maintenance, repairs and cleaning procedures (October 2003) 

Dangerous Substance and Explosive Atmospheres – Approved Code of Practice and Guidance

L139 HSE Books ISBN 0 7176 2203 7 (£15.50) (February 2004)

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