You may think that one gas cylinder is much the same as any other, but they can be very different.

Dispense gas (CO2 and the different mixed gases composed of CO2 and nitrogen), are regulated the same way as food products. There is more and more legislation in respect of food safety and increasing scrutiny of equipment and premises connected with food service.

Consequently, everyone in the industry needs to be aware of the stringent standards for testing and filling cylinders. These standards are laid down in the law, and it is vital to follow them to the letter.

In some cases water, soft drink syrups or cleaning fluids can enter a cylinder while it is connected to the gas lines in a pub. Water can react with CO2 in the cylinder to form an acid which then slowly corrodes the metal cylinder until it becomes thin and unable to contain the pressurised contents.

When a corroded cylinder is repeatedly filled with CO2-rich gases and kept at high pressures, it can become unsafe (particularly with water or other contaminants inside).

An unsafe cylinder can rupture without warning, either when it is being filled, while being transported, stored in the cellar or connected to the gas lines.

Anyone in the vicinity of an exploding cylinder could suffer severe injuries and it could cause considerable damage to a building.

Why put your safety, the safety of your staff and the future prosperity of your business at risk?

BOC Sureserve test shops are accredited to:

• National Certification Scheme for In-Service Inspection Bodies (BS5430)
• Carriage of Dangerous Goods (Classification Packaging and Labelling)
• Use of Transportable Pressure Receptacle Regulations 1996

We consistently remove 2% of our cylinder population each year as a result of our stringent testing procedures.

BOC Sureserve alone has over 700,000 cylinders in the UK and we estimate that there are about four million cylinders in circulation.

Cylinders are filled with pressurised gas, therefore they are classed as 'pressure vessels' and every aspect of their use is subject to strict regulation.

The pressures in dispense gas cylinders vary from 823 lbs per square inch (50 bar) for pure CO2 up to 3000 lbs per square inch (200 bar) for a mixture of CO2 and nitrogen.

The percentage of CO2 used will vary depending on the product being dispensed.

• soft drinks use pure CO2
• lagers and keg beers will use between 40% and 60% CO2
• stouts and creamflow products will use 30% CO2

By law, cylinders have to be tested every five or 10, depending on the type of product. This inspection includes:

• visual examination of the interior of the cylinder
• re-weighing of the cylinder
• high pressure hydraulic test to ensure that the strength of the cylinder has not deteriorated (in accordance with BS 5430 Part 2)
• re-painting to ensure the cylinder is well presented and does not corrode before the next test
• a new or reconditioned valve to ensure that water cannot enter the cylinder before the next test
• metal stamping and re-labelling to confirm that the cylinder has been tested by an accredited work shop.

These tests ensure that cylinders are safe, undamaged, not corroded and can continue to withstand high service pressures.

How do you tell whether or not a cylinder is certified as being safe?

Unfortunately it is not easy to recognise which cylinders are safe and meet industry standards - and which are not.

One cylinder looks much like another. If illicit fillers have stolen cylinders from BOC Sureserve or another reputable supplier, they are quite likely to have a well-respected brand name on the side.

Externally a cylinder may look to be in reasonable condition, but the interior may be severely corroded and in very poor order.

BOC Sureserve does not fill cylinders for any other supplier or allow BOC Sureserve cylinders to be filled by any other company.

If you take deliveries from a local supplier who supplies gas in BOC Sureserve cylinders, it is highly likely that the cylinder has been filled illegally.

You should report this immediately to the BOC Sureserve Customer Services Centre by telephoning 1800 355 255. We will immediately send someone to collect the cylinder.

Apart from the risk that an illegal cylinder poses to life, limb and property, there are several other 'downsides':

• your insurance may be invalidated. If there was an accident and it was caused by an illegitimately filled cylinder exploding, the insurance company may refuse to pay out
• the landlord may then be personally liable for costs and damages arising from the accident
• landlords have obligations under the Health and Safety at Work Act, and may be personally liable to prosecution if a serious accident occurred and employees were injured
• landlords may be invalidating their tenancy or lease by storing dangerous and/or stolen products in their cellars.