I've heard a few people say that 'arb' helmets should not be used on the ground, which always struck me as slightly odd when they are built to withstand a stronger impact than the standard forestry helmet (arb helmets area built to EN12492, forestry helmets to EN397).
So, in a bid to clarify the situation, I contacted the Health & Safety Executive to find out what the actual answer was - here's the reply from Dr Andrew Turner, the Principal Inspector of Health & Safety in the Agriculture, Forestry and Arboriculture Team...
"Dear Mr Vickers
I refer to your query regarding the above.
UK legislation does not specify the choice of PPE, but requires that where PPE is used as a means of reducing risk of injury or ill-health, it must be suitable. The actual choice is likely to be down to a specific risk assessment for the activity and environment in which the work activity is taking place.
For work which involves climbing, helmets to EN12492 provide advantages over helmets to EN397 for the reasons described in your enquiry. In addition, the chin strap ensures that the helmet is less likely to be dislodged when climbing or moving within the canopy. Climbing work inevitably involves work on the ground, and it would be impractical to require a climber to use a different helmet while working from the ground, and there do not appear to be any reasons why a helmet to EN12492 would not provide adequate protection for a ground worker supporting arboriculture work, especially where there is a risk of falling objects.
A helmet to EN397 is also likely to provide adequate protection for a ground worker and is the preferred choice in forestry. Such a helmet is unlikely to provide adequate protection during climbing as it may be dislodged and may not provide adequate protection to side impact.
However, a complicating factor is that not all manufacturers producing helmets to EN12492 approve them for use in groundwork, which is a matter which should be taken up with the manufacturer.
I have looked at our website regarding your comments, and it is likely that this will be amended to more accurately reflect the advice above.
Here's what I sent, just to give the context...
"As a trainer within the forestry and arboriculture industry, I am seeking advice on the EN397 and EN12492 standards as I come across conflicting information, recommendations and guidance regarding the use of 'arboriculture' helmets that meet EN12492 being used for ground work (where EN397 also applies).
A helmet that meets the EN12492 standard is built to withstand vertical forces twice that of the EN397 standard, as well as side impact loading (which is an optional test for EN397). Despite this, I have heard of several assessors, and indeed had several conversations with others who hold the view that an 'arboriculture' helmet cannot be used on the ground e.g. for forestry work.
The INDG317 merely states that for chainsaw work a "safety helmet to EN397" (p.8) should be worn, and as EN12492 would appear to exceed EN397 then one assumes that these helmets can be worn for chainsaw use on the ground.
However, the HSE website at http://www.hse.gov.uk/treework/safety-topics/chainppe.htm seems to state that these helmets are not suitable for work on the ground. FISA301: Using petrol drive chainsaws (what was AFAG301) also states helmets must meet EN397... which helmets meeting EN12492 would appear to do.
Can you please clarify the situation regarding the use of EN12492 helmets for use on the ground?
So what are we to make of this? I think the key to it all is the comment about it being "down to a specific risk assessment for the activity and environment".