What is HSG51?
HSG51, "The Storage of Flammable Liquids in Containers," is the Health and Safety Executive's definitive guidance on safely storing flammable liquids in portable containers. This guidance applies to containers with capacities up to 200 litres, covering everything from small jerry cans to standard drums.
The document addresses the significant fire and explosion risks associated with flammable liquid storage. Flammable liquids are ubiquitous in workplaces, from petrol and diesel in vehicle maintenance to solvents in manufacturing, cleaning agents in commercial premises, and fuels in construction. Without proper storage arrangements, these materials present serious risks to life and property.
HSG51 provides a risk-based framework for determining appropriate storage arrangements. It recognises that storage requirements vary based on the quantity stored, the flash point and volatility of the liquids, the location of storage, and the nature of surrounding activities. This proportionate approach helps businesses implement suitable controls without unnecessary expense.
The guidance supports compliance with multiple legal requirements including the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002, the Regulatory Reform (Fire Safety) Order 2005, and building regulations. It represents established good practice accepted by fire authorities and enforcing agencies.
Who Needs This Document?
HSG51 is relevant to a wide range of businesses handling flammable liquids:
Primary Audiences:
- Warehouse and stores managers handling flammable products
- Vehicle maintenance and motor trade premises operators
- Manufacturing facility managers using solvents or fuels
- Construction site managers storing fuel and chemicals
- Facilities managers responsible for chemical storage
- Health and safety professionals conducting DSEAR assessments
Secondary Audiences:
- Retail premises storing cleaning solvents or aerosols
- Painting and decorating contractors
- Printing companies using flammable inks and solvents
- Agricultural businesses storing fuel and pesticides
- Schools and colleges with science laboratories
- Healthcare facilities with flammable substances
Any workplace that stores flammable liquids in containers should refer to HSG51, regardless of sector or size. The principles apply whether storing a few litres of cleaning solvent or hundreds of drums of fuel.
Key Topics Covered
HSG51 provides comprehensive coverage of flammable liquid storage requirements:
Understanding Flammable Liquids
The guidance explains key concepts about flammable liquids:
- Flash point and its significance for fire risk
- Classification of flammable liquids by hazard category
- Understanding vapour behaviour and explosion risks
- Ignition sources and how fires start
- The relationship between temperature and vapour production
- Reading safety data sheets for hazard information
Risk Assessment
Central to HSG51 is the requirement for risk assessment:
- Identifying what flammable liquids are stored
- Assessing quantities and hazard characteristics
- Evaluating storage locations and surrounding risks
- Identifying potential ignition sources
- Determining who might be affected
- Documenting assessment findings
Storage Location Options
HSG51 describes various storage arrangements:
- Storage within workrooms (limited quantities)
- Dedicated storage rooms within buildings
- External storage areas and compounds
- Purpose-built flammable liquid stores
- Flammable storage cabinets
- Considerations for each option
Quantity Thresholds
The guidance provides thresholds for storage decisions:
- Workroom storage limits based on flash point
- When dedicated storage becomes necessary
- Quantities requiring fire-resisting construction
- Thresholds affecting building regulations
- Licensing requirements for petroleum storage
Construction and Design
Requirements for storage areas and buildings:
- Fire resistance periods for walls and structures
- Ventilation requirements for vapour control
- Flooring and bunding for spill containment
- Drainage considerations
- Door and opening specifications
- Electrical installation requirements
Ignition Source Control
Critical guidance on preventing fires:
- Identifying and eliminating ignition sources
- Electrical equipment in hazardous areas
- Hot work procedures and controls
- Static electricity hazards and bonding
- Smoking and naked flame policies
- Vehicle and equipment considerations
Spill Prevention and Containment
Measures to control liquid releases:
- Bunding requirements and sizing
- Materials suitable for bund construction
- Managing rainwater in bunded areas
- Spill response equipment and procedures
- Drainage controls and interceptors
Separation and Segregation
Keeping flammable liquids away from risks:
- Separation from buildings and boundaries
- Protecting storage from vehicle impact
- Segregation from oxidising materials
- Separation from incompatible substances
- Access control and security
Fire Protection
Fire safety measures for storage areas:
- Fire detection and alarm systems
- Fire extinguisher provision
- Emergency access for fire services
- Fire service information plates
- Maintaining separation in fires
Container Requirements
Specifications for containers:
- Approved container standards
- Keeping containers closed
- Labelling requirements
- Container condition and inspection
- Maximum container sizes for different purposes
Using This Guidance
Implementing HSG51 effectively involves the following steps:
Step 1: Inventory Your Flammable Liquids Create a comprehensive list of all flammable liquids stored at your premises. Record product names, quantities typically held, flash points, and hazard classifications. Safety data sheets provide this information.
Step 2: Review Current Storage Arrangements Document how and where flammable liquids are currently stored. Note container types and sizes, storage locations, proximity to ignition sources, and existing control measures.
Step 3: Conduct Risk Assessment Using HSG51 guidance, assess whether current arrangements adequately control risks. Consider quantities stored, hazard characteristics, location risks, and potential consequences of fire. Document your assessment under DSEAR requirements.
Step 4: Determine Appropriate Storage Based on your risk assessment, identify what storage arrangements are needed. This may range from a flammable cabinet for small quantities to a purpose-built store for larger amounts. Use HSG51 thresholds to guide decisions.
Step 5: Address Ignition Sources Systematically identify and control ignition sources near storage areas. This includes electrical equipment, hot work, vehicles, static electricity, and smoking. Implement appropriate controls or relocate storage away from risks.
Step 6: Implement Spill Containment Ensure appropriate bunding or containment for your storage arrangements. Size bunds correctly, maintain their integrity, and have spill response equipment available.
Step 7: Establish Procedures Develop procedures for safe handling, storage, and dispensing of flammable liquids. Include container management, stock rotation, spill response, and emergency procedures. Train relevant staff.
Step 8: Maintain and Monitor Regularly inspect storage areas, containers, and control measures. Address any deterioration or non-compliance promptly. Review arrangements when quantities or products change.
Why It Matters
Proper flammable liquid storage is essential for multiple reasons:
Preventing Fires and Explosions: Flammable liquid fires can spread rapidly and explosively, causing fatalities, serious injuries, and catastrophic property damage. Proper storage arrangements prevent these incidents.
Legal Compliance: The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) require employers to assess and control risks from dangerous substances including flammable liquids. HSG51 provides the benchmark for demonstrating DSEAR compliance for container storage.
Fire Safety Order Compliance: The Regulatory Reform (Fire Safety) Order requires fire risk assessments and appropriate precautions. Proper flammable liquid storage is a key element of fire safety for premises holding these materials.
Insurance Requirements: Insurers expect flammable liquids to be stored according to recognised guidance. Non-compliance can invalidate coverage or significantly increase premiums. Many policies specifically reference HSG51 standards.
Licensing Requirements: Storage of petrol above certain quantities requires a petroleum storage certificate from the local petroleum licensing authority. HSG51 helps ensure storage meets licensing conditions.
Protecting Neighbours: Flammable liquid fires can spread beyond premises boundaries, affecting neighbouring properties and the community. Proper storage and separation distances protect third parties.
Business Continuity: A fire involving flammable liquids typically destroys not just the storage area but often the entire premises. Proper storage protects your business assets and ability to continue trading.
Environmental Protection: Flammable liquid releases can cause serious environmental contamination. Containment measures required by HSG51 also prevent pollution incidents.
Enforcement Action: Fire authorities and HSE can take enforcement action where flammable liquid storage is inadequate. This can include prohibition notices stopping business activities until improvements are made.
By following HSG51 guidance, businesses can store flammable liquids safely and legally, protecting workers, premises, and the surrounding community from the serious consequences of fires and explosions.