By the UK Generator Guide — Home Petrol Generator Reviews & Advice Team · Updated May 2026 · Independent, reader-supported

How to Store Petrol Safely for a Home Generator UK: Rules & Best Practice

Keeping a home petrol generator topped up with fresh fuel sounds straightforward, but storing petrol safely requires more than just shoving a can in the shed. In the UK, fuel storage is governed by specific regulations, and getting it wrong can void your insurance, breach fire safety law, or worse. This guide covers what you legally need to do and what actually works in practice.

UK Legal Requirements for Petrol Storage

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) is the framework that governs how you can store petrol at home. Most householders aren't aware they're bound by it, but you are.

Under DSEAR, you can store up to 20 litres of petrol in a domestic property without needing a licence—but only in approved containers. That 20-litre limit is a hard cap. Exceed it, and you need a Petroleum Licence, which means inspection and formal approval. For a home generator, you're almost certainly staying under 20 litres anyway, but it's worth knowing the boundary.

Your local authority's fire safety team can and will inspect if there's a complaint or incident. Non-compliance can result in enforcement action and invalidates home insurance claims if a fire occurs.

Choosing the Right Container

Not all jerry cans are equal. The UK recognises two main standards: BS 1457 (steel cans) and BS 2037 (plastic cans). Buy either of these and you're compliant. Avoid unmarked cans from discount retailers—they often lack the required baffles, venting systems, and durability.

Steel cans (typically red for petrol, blue for diesel, green for oil) are tough and last decades. They're heavier to handle and prone to rust inside if not maintained, but they're reliable. A properly made steel jerry can with a tight cap will keep petrol stable for months.

Plastic cans (translucent HDPE, usually yellow or red) are lighter and less prone to corrosion. Modern plastic cans are better than they were, but petrol degrades them faster than diesel. They also leach petrol fumes more readily. If you choose plastic, buy a quality brand marked BS 2037 and don't store filled cans for more than six months without treatment.

Regardless of material, the container must be:

• Clearly marked "Highly Flammable"
• Fitted with a secure, self-closing cap
• Equipped with a pourer or spout (not a removable funnel that you can lose)

The cap is critical. A loose cap means vapours escape, petrol degrades faster, and you're creating a fire hazard. Check it before every use.

Storage Location and Conditions

Location matters as much as the container. Your garage, garden shed, or outbuilding must:

Be well-ventilated. Petrol evaporates and creates flammable vapours. A sealed shed is a bomb waiting for a spark. Ensure air can circulate—ideally a slightly open window or vent in the shed, away from the jerry can itself.

Stay cool. Petrol expands in heat and becomes more volatile. Store cans in the coolest, shadiest part of your shed or garage. Direct sunlight accelerates degradation and increases pressure inside sealed containers. In summer, even a dark shed can reach 30°C; petrol's flashpoint drops as temperature rises.

Keep away from ignition sources. No smoking, no electrical equipment with exposed switches or motors that spark, no boilers or heaters running in the same space. A petrol-soaked rag and a pilot light 5 metres away have ended homes.

Store upright and stable. Cans must sit on a stable, level surface—not on a shelf where they might tip. A spilled jerry can of petrol will find its way across your garage floor and into cracks. Concrete is preferable to wood, which absorbs the liquid and becomes a fire hazard itself.

Separate from other hazards. Don't store petrol next to household chemicals, fertilisers, or paint thinners. Incompatible chemicals can react or intensify fume hazards.

Fuel Degradation and Stabilisers

Petrol doesn't last forever. Within three to six months, especially in warm conditions, it oxidises and loses octane. A generator running on degraded fuel will struggle to start, misfire, and clog the carburettor with varnish deposits.

For home generators, a fuel stabiliser extends this window significantly. Products containing alkyl nitrite or metal deactivators prevent oxidation and keep fuel fresh for up to a year. Add stabiliser to the petrol when you pour it into the can—don't add old petrol to an already-stabilised can. A small bottle treats up to 30 litres.

Stabilisers aren't essential if you're using the generator regularly and rotating fuel every few months, but they're cheap insurance for occasional users.

Practical Safety Tips

• Label your can with the date you filled it. Petrol older than six months without stabiliser should be disposed of properly, not poured into your generator.
• Use a funnel when filling the generator. Spilled petrol in the carburettor area will ignite if the engine is running.
• Never fill indoors. Fuelling a generator in a garage or shed is a serious fire risk. Do it outside, away from buildings.
• Keep a fire extinguisher nearby—specifically one rated for flammable liquid fires (Type B). A standard kitchen extinguisher won't help.
• Wash hands after handling. Petrol is a skin irritant and can be absorbed through the skin with repeated exposure.
• Never siphon by mouth. If you need to transfer petrol, use a manual hand pump designed for the purpose.

Storage Checklist

Before you assume your setup is safe, run through this:

• Container is marked BS 1457 or BS 2037
• Cap is tight and self-closing
• Location is cool, well-ventilated, away from ignition sources
• Can is stable and upright
• No more than 20 litres stored in your home
• Fuel is labelled with date
• Stabiliser has been added if storing longer than three months

Storing petrol for a home generator doesn't need to be complicated, but it does need to be done right. A small investment in a proper container and a bit of thought about location keeps you legal, keeps your insurance valid, and keeps your family safe.