Here's a pelican page that describes "What makes a flashlight safe?" and links to two videos. The first video says that the Sabrelight has more approvals than any other pelican light.
http://pelican.com/safety/
At the brightguy link above, there are several pelican headlamps (and others, mostly flashlights, though) that have the "safety" field showing an approval.
Just to be a geek here, you're really not looking for an "intrinsically safe" light. You're really looking for a light that is approved for use in "Hazardous (classified) locations" as defined by the National Fire Protection Agency (NFPA) Publication 70 (NFPA 70), which is known as the "National Electrical Code". Specifically, you're interested in Article 500, "Hazardous (classified) locations", and the few articles after that, up to 504 or so.
Having said that, it's unclear to me what specific mitigation technique these flashlights use. They're clearly not explosion-proof, which is a specific method for achieving safety that involves tight-fitting flanges that, believe it or not, allow an explosion inside the "box", but quench the flame in these flanges. It may be that these flashlights are considered "Intrinsically safe", but I don't see how. The ones I have always list a group, as in "Class I, Div I, Group D". My interest has always been in Group D, which includes things like gasoline and propane. Group A is specifically for Acetylene, which in contact with copper is really nasty. Groups B and C are more hazardous than Group D. Class II is for dusts, and includes Groups E, F, and G, where E is nasty, F is things like carbon black and coal, and G is for grain dusts, wood dusts, etc. You've probably seen demonstrations of wood dust ignition, so even the least hazardous Groups, D including gasoline and propane, and G including wood and grain, are serious, serious hazards.
It's interesting to compare the specifications of the Sabrelight 2000
http://pelican.com/lights_detail_specs.php?recordID=2000
to the LED Sabrelight 2020, which has an LED.
http://pelican.com/lights_detail_specs.php?recordID=2020
Why are these certifications different? My guess is that it costs money to have these tested, and Pelican didn't spend it on certain models. It's also interesting to compare the differences between the certifying groups, for example, UL and FM. They end up approving the light for different levels of hazard.
Here's a pelican LED headlamp with some certifications (interestingly not UL):
http://pelican.com/lights_detail_specs.php?recordID=2680
The NEC (NFPA 70) defines "approved" as "Acceptable to the authority having jurisdiction", so my recommendation is to find out who that is for you, and then find out what they'll accept.
I'd also recommend knowing what the gear is approved for, and to not go beyond it. The one problem with the Articles 500-504 is that they're very difficult to understand. I'd recommend reading paragraph 500-3 as a minimum, and then to look for people who have been through this before or who have written articles explaining articles 500-504. These articles also reference NFPA documents that I don't have access to (since I don't work with these anymore), and which might be helpful.
I'm sure it doesn't need to be said, but take good care of these. Things like torn O-rings or a little crack in the bezel are unacceptable.
Finally, I don't have any financial interest in Pelican, I was just using their products as examples. If a light's got the certifications, that's all I care about.
Edits:
I also noticed that brightguy's safety field is sometimes not shown even when Pelican would report a certification.
The Streamlight link above probably meant to point at this headlamp:
http://www.brightguy.com/products/Streamlight_3AA_HAZ-LO_Div_1_Headlamp.php
