Tuesday 24 June 2008

Chainsaw Safety Clothing

Regulations generally recommend that chainsaw users wear protective clothing, also known as Personal Protective Equipment or PPE, while operating chainsaws. There is general agreement worldwide on what clothing is suitable, but local jurisdictions have specific rules and recommendations.

Clothing Types

Helmet

The helmet attempts to protect the user's head against impact with the cutter bar of the chainsaw should a kickback occur. This can only be successful if the chain brake has operated to stop the cutter chain. A chain running at full speed easily cuts the helmet.

The helmet also protects against impacts from small falling objects, such as a dead branch from a tree being felled.

The image shows a helmet which integrates visor and ear defenders into one unit. This is a very popular arrangement with chainsaw users.

In the EU, the helmet must meet the requirements of EN397.

Visor or Goggles

A visor or goggles reduce the chance of chips penetrating the user's eyes.

The relatively flimsy visor, with imperfect coverage of the face, is considered acceptable because the chips produced by chainsaws are of relatively uniform size and speed. Unlike other woodworking tools, a chainsaw produces little or no sawdust, only chips. The chips are too large to fit through the visor's mesh.

Some chainsaw users prefer conventional safety goggles. The choice may depend on the environment. The visor provides better ventilation for hard work in hot weather.

In the EU, a visor must comply with EN1731, or goggles must comply with EN166.

Ear defenders

Ear defenders and ear plugs attenuate noise to levels that cause little or no damage to the user's hearing. The chainsaw is very loud, typically 115 dB.

In the EU, ear defenders must comply with EN352.

Trousers

Special fabrics have been developed for chainsaw clothing, and this development is still very active. Conventional fabric is useless at protecting against a running chainsaw, being immediately cut through.

There is a real struggle between making a fabric proof against more violent impact, and making it light, flexible and comfortable enough for the user. Clothes which make the user too hot, or which prevent the user moving easily, are a safety problem in themselves. A worker suffering from heat exhaustion is not safe. Extra fabric layers can be added to clothing to improve cut resistance, but clothes which cannot be cut at all by a powerful saw are impractical, even with modern fibres. What is worse saw and chain technology seems to be outstripping fabric technology. High power saws with aggressively cutting chains are almost impossible to protect against.

A classification scheme has been developed in the EU to rate trousers, and fabric in general, for protection against cutting.

Chainsaw Fabric Classification

Class

Max chain speed m/s

0

16

1

20

2

24

3

28

The chain speed is specified in the manual for a chainsaw. Higher class trousers cost more and are heavier, so there is an advantage to choosing the trousers to match the saw.

There are two standard types of trousers, Type A and Type C. Type A protects only the front of the legs, and can be supplied not as full trousers but as chaps, worn over conventional work clothes. Types C gives protection all round the legs and are almost always worn as ordinary trousers; not over another garment. In the EU, most workers choose to wear type C trousers.

Chainsaw protective fabric works on a number of principles. The outermost layer can be made both tough and slippery, so that the chain skids across it rather than cutting in. Lower layers of fabric can be tough to cut, absorbing saw power. The final defence is that long fibres of the protective fabric (commonly Kevlar) are drawn out by the running saw, not cut through. These long fibres travel with the chain to the saw drive sprocket, where they jam the mechanism and stall the saw. After this, the saw has to be taken apart for cleaning out. Chainsaw protective trousers in the EU must comply with EN381-5.

Gloves

Chainsaw gloves have cut-proof fabric protection like that for trousers, but only on the back of the left hand. It's especially important that work gloves are flexible, which limits how much padding they can have. Experience has shown that most chainsaw injuries to the hands occur on the back of the left hand.

In the EU, chainsaw gloves must comply with EN381-7.

Boots

Chainsaw boots are based on ordinary steel-toe boots, but have layers of chainsaw protective fabric on the exposed front surfaces. They are available in lace-up leather or rubber Wellington boot versions.

In the EU, chainsaw boots must comply with EN345-2.

Logos for Fabric

Chainsaw Logo

In the EU, chainsaw trousers, boots and gloves (the items containing chainsaw protective fabric) must carry a special chainsaw logo. This shows that the fabric is of a type tested to protect properly, and also shows the class of protection, the rated maximum chain speed.

Additional Personal Protective Equipment (PPE)

First Aid Kit

In the UK, workers are required to carry a first aid kit containing at least a large wound dressing.

Whistle

In the UK, workers are recommended to carry a whistle to call for help if they are injured. Colleagues may be close by, but unable to hear over the noise of chainsaw(s) still running. The whistle tends to overcome this.

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