Use of chain flail/non standard cutting attachments on brush cutters

Health and Safety Executive - Safety alert

Department Name:
Operational Strategy Division - Agriculture and Waste Recycling Sector

Bulletin No:
OPSTD 1-2013
Note: this bulletin replaces Bulletin No. OPSTD 3-2011 and Bulletin No. FOD CON 3-2010

Issue Date:
12 November 2013

Target Audience:

  1. Suppliers and users of portable hand held brush cutters in arboriculture and the agriculture and construction industries
  2. Relevant trade associations

Key Issues:
The European Commission (DG Enterprise and Industry) has required Member States to prohibit the placing on the market of flail-type cutting attachments consisting of several linked metal parts (eg chains) for portable hand-held brush cutters. Non-standard metal brush cutting accessories fitted to petrol driven brush cutters can fail catastrophically in-service.

There is a risk of death or serious injury to operators and others in vicinity from ejected metal components. These accessories are manufactured from more than one component and rotate at high speeds.

Suppliers of such equipment should immediately discontinue supply of flail-type cutting attachments for portable hand-held brush cutters. Anyone using them should discontinue use of any non-standard metal cutting accessory immediately and consult the brush cutter manufacturer for guidance.


A serious risk has been identified with this type of attachment for brush cutters. This problem was first identified in Sweden a few years ago (see below). In 2010 a fatal injury occurred in the UK following which the UK obtained voluntary agreement from the UK distributor to stop supply of this particular device. The UK also issued a safety alert to warn industry, workers and the public of the risk of this type of device and ask that they no longer be used.

Previously, Sweden had warned Member States about the sale of brush cutter attachments of various types and origin that were made up of linked parts (eg an attached chain) instead of the single one-piece metal blade or nylon string dispenser supplied by the manufactures of the brush cutter.

The harmonised standard EN ISO 11806 does not cover this type of device as only nylon strimmers and single piece metal brush cutting blades are in scope for fitting to the basic brush cutter.

Portable, hand-held, combustion engine driven brush cutters are commonly used for cutting weeds, brush and similar vegetation, and are frequently utilised in ground-clearance operations, including those connected with construction work, using a variety of standard cutting attachments.

The Health and Safety Executive (HSE) has become aware of a dangerous practice involving the fitting of non-standard accessories, not approved by the manufacturers, to brush cutting machines. In particular, HSE are aware of the UK supply of chain flail attachments comprising a cutting head incorporating lengths of metal chain. This alert is relevant to any metal brush cutter accessory manufactured or assembled from more than one component.


In contrast with dedicated chain flail machinery, brush cutters typically lack the robust guarding arrangements required to control the risk from articles (including fragments of chain) being ejected with high energy. The guarding supplied with brush-cutters is predominantly aimed at protecting the operator from inadvertent contact with the cutting accessory.

The fatal incident involved the use of a twin-chain attachment, similar designs have also been encountered having 4 chains, swinging metal blades and one which utilises shot lengths of chainsaw cutting chains as the cutting implement.

The presence of a CE mark should not be regarded as a reliable indication that such attachments are safe to use.


  • The high output shaft speed of a brush cutter creates the potential for significant energy to be transferred to the cutter head. The chains affixed to non-standard cutter heads are subject to high stresses and impacts during normal use, and the risk from breakage and ejection of chain components at high speed is significant.
  • The use of non-standard cutting attachments not approved by the manufacturer may, because of their geometry and mass, induce excessive stresses which could result in premature failure and possible break-up of the brush cutter, thereby increasing the risk of injury from any ejected component.
  • Manufacturers' original cutting equipment such as nylon cords, metal cutting blades and saw blades are designed to be used in combination with specifically designed safeguarding systems. The chain flail attachments are not supplied with any compatible safeguard/deflector.
  • The harmonised standard for specifying the safety requirements for such machinery, EN ISO 11806, excludes from its scope brush cutters equipped with metallic blades having more than one part (such as chain links.)

Decision of the European Commission

Following a Safeguard Action brought by HSE under Article 11 of 2006/42/EC, the European Commission - advised by the Machinery Committee, required Member States to prohibit the placing on the market of flail-type cutting attachments, consisting of several linked metal parts (eg chains), for portable hand-held brush cutters, see European Commission Decision on the marketing of flail-type cutting attachments for portable hand-held brush cutters

Action required:


  • Any brush cutters fitted with flail or similar non-standard attachments, consisting of several linked metal parts (eg chains) should be taken out of service immediately and the attachments removed and replaced with the manufacturer's approved accessory.
  • Manufacturers' advice should be followed as to the appropriate combinations of cutting tools and guards. Such advice is typically available within the instruction books accompanying the machine.


UK suppliers should immediately cease the supply of cutting attachments consisting of several linked metal parts (eg chains) whether or not intended for "professional use."

Relevant legal references:

Note: The EU Commission is of the view that chain flail attachments are interchangeable equipment within scope of the Machinery Directive as listed in Art 2(b)

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