You fire prevention people work cheap......Spule 4:70254 wrote: Not a problem, my billable rate is $115 an hour tho at work, who do I need to send my invoice to? :lol: :P :D
As an Industrial Hygienist of mumble mumble years experience I'd be charging over $US200 an hour if I'd gone into consulting instead of retiring early.
Most of which would be to pay for the professional indemnity insurance. 
The NIOSH doc you referred to is very old and probably past it's use by date. Also OSHA no longer have a PEL for Butane.
OSHA list the health hazard that I was trying to convince you about on their Safety and Health topic on Butane and there is more detail in the medical literature, if you do an online search in PubMed. http://www.osha.gov/dts/chemicalsamplin ... 22200.html
The ventricular fibrillation health hazard is realistically only a risk for substance abusers, as you need something like 150,000 ppm (15% in air) to initiate it. No workplace could get to that level, as it would blow up at about 20,000 ppm.
The Occ. Hygiene approach to simple asphyxiants in the workplace is to ensure that the oxygen level doesn't drop below some value (18% in Aust., 19% in the UK, 19.5% in the US) and if the substance is also flammable we would test for LEL first. This is why the flammable asphyxiants like methane, acetylene etc., don't have a workplace exposure standard.
I suspect our different backgrounds is why I'm more focussed on health effects than you are. Anyway........
Trick question for you, which is relevant to this group.
There is the equivalent of ~85 litres of butane gas in a 220g can of butane. If a can springs a leak in my 3m x 6m x 2.5m workshop, am I over or under the LEL?
Graeme
