HSA issues alert for large tyre inflation

A series of fatal accidents involving large tyre inflation in 2014 has prompted the Health and Safety Authority to issue this safety alert to highlight the need for safe procedures during large tyre inflation in all work sectors.

This safety alert deals with the dangers associated with large tyre inflation

Dangers of explosive energy stored in tyres

Inflated tyres contain a large amount of stored energy. For example, the sidewall of a typical commercial vehicle (CV) tyre typically has over 34 tonnes of force acting on it.
Tyres are designed to withstand this but if they are damaged or used while flat [run flat], or significantly underinflated, they may fail.
The force can then be released explosively and result in a destructive air blast and the ejection of high-speed particles. These types of tyre explosion have led to numerous deaths at work

Risk of failure

Removal, replacement and inflation of tyres is an extremely common practice, so it may seem a simple task. But it can cause very serious injury and death from:

explosion of the tyre or disintegration of the wheel during inflation
manual handling of the tyre and wheel
collapse of an elevated vehicle

Cuts and splits should be clearly visible by inspection and there are industry standards on whether a repair should be attempted.

However, damage to the internal steel or textile cords may not be obvious.

This internal damage may not become obvious until the tyre is reinflated and a bulge occurs. At this stage, the additional strain placed on the adjacent cords can cause them to break in rapid succession, until the casing splits apart violently. This is commonly known as a 'zipper-failure'

To reduce the risk of violent explosion

Before deflating a tyre, check the pressure and chalk the reading on the tyre wall. Remember, low tyre pressure may have caused tyre wall damage.

Do not inflate any tyre that has been significantly underinflated until it has been adequately checked. Examine wheels and tyres (externally and internally) for signs of damage, such as cracks, 'marbling' (black lines), bulging, soft spots or exposed steel cord in the tyre carcass. If in doubt, DO NOT re-inflate the tyre.
Stay outside the likely explosion trajectory, when reinflating a tyre.
Watch and listen for signs that might indicate a zipper failure. If you suspect a problem, do not approach the tyre to deflate it - use the quick-release connection at the operator's end of the hose.