Hello OPJ
I've only researched these matters as an amateur but like many others I have some interest in becoming professional with the woodwork at some point. Therefore, when I was uprating machines about a year ago I decided to ensure that replacement equipment would pass relevant HSE requirements - I didn't want to set up shop & then be told my saw or extraction didn't meet the relevant requirements per Health and Safety directives.
When looking at dust extractors I found that there appeared to be less stringent requirements for dust extraction where only soft wood was being sawed. THis was nothing to do with the quantity of dust remaining in the air to be breathed in by the carpenter, but entirely to do with risk of fire and explosion.
Some HSE documents state that sawn softwood produces dust not likely to be an explosion risk, unlike sawn hardwood or man-made board products which are considered to be such a risk (this distinction according to, for example : link
>
http://www.hse.gov.uk/pubns/wis32.pdf
and I quote :
"machining and sawing softwoods which produces
chips, shavings and coarse dust with only a small
amount of fine dust. This does not normally create
an explosion risk, so long as the fine dust is not
allowed to separate and accumulate within
confined spaces;
● sawing and machining hardwoods which often
produces woodwaste containing considerably more
dust than that from softwood. Assume this is explosible."
I concluded therefore that hardwood and man-made board waste needed greater containment and control than sawdust from sawn softwood.
This also implied that ATEX137 (governing control of explosive dusts such as wood dust) did apply to all kinds of woodwaste, but that softwood waste (generated by sawing) would not be considered an explosion risk in smaller quantities (unlike hardwood waste) and thus not need extraction equipment compliant with ATEX137 (such as having explosion relief panels or vents issuing to outside of the building).
Hope you're still awake at the back there !
Regards, Catface.
Its not a distinction that matters much unless you're going to only process softwood, not board or hardwood. As I mainly like working with Hardwoods my kit will need to be compliant with the relevant regs. including ATEX 137.