I don't think it has to do with what type of contact. It is the fact that in the dive lights that the contacts are on the inside of the waterproofing.



I don't think they are intrinsically any safer or less safe. Keep in mind their are fairly large differences in design between the Photon models. For example, the Photon I & II have no waterproofing and I would say they would be very bad choices for flamable gas. On the other hand, the Photon III has some waterproofing and would probably be much better.

On the other hand, personally, I'd look to lights like the UK MiniQ40 or UK 2L for this type of service. I'm not sure what the ratings on these lights are, but they are mega-waterproof, plastic (no spark if dropped).

-john

Careful there, Biggzie. This "California earthquake divorce" can work both ways, y'know. I'm sure the ladies down at the supermarket are talking about exactly the same thing right now...<img src="/images/graemlins/shocked.gif" alt="" />

But regarding the rest of your post, now I understand your point and yes, it happens all the time. True, it appears that what you described was the case with these Streamlight Propolymers since only the 4AA model has the additional certification from the US Mine Safety and Health Administration although all three models are probably equally safe.

Here in the US, I think most relatively knowledgable consumers see, say, the Underwriter Labs' UL logo on products as some sign of quality/safety, but most people probably don't realize that manufacturers actually have to pay to get these products tested. I think most consumers think that the UL testing is paid for by the government, or that the UL is actually part of the government, so that if the logo is missing, the product must somehow be inferior. That may not be true, but the there's always that doubt.

For example, I've been meaning to buy a fire escape ladder for my bedroom for a long time because the front door is only escape route out of the apartment. However, I've only seen one UL-approved fire escape ladder. There are other cheaper, more compact ladders out there that appeal to me, and I have to admit that I'm a bit hesitant to buy them knowing that there's a UL-approved one out there although it's more expensive, heavy and bulky. The unapproved ladders are probably good enough, just like your friend's boots, but then again, there's that "but how do we know?" voice in the back of my head.

Benjammin, what's an FM rating? At first glance, I keep wanting to think it's some sort of radio signal shielding thing.

Just a wild guess, but I wonder if bomb disposal or building demo guys need to worry about radio signals from their flashlights (I'm sure it's a concern for other electronics they may carry) since they can work around radio-triggered explosives.

UL [Underwriters Laboratory] is a volutary testing organization that has been and often is tricked by munufacturers. I had a case involving a counter top appliance that was required to generate water at a maximum of 140 degrees F. The manufacturer submitted samples to UL for testing, and the first batch failed, making about 165 degrees. They resubmitted a new sample batch, which passed.

Trouble was, they already had made 50,000 units with the higher temp thermostat. They retrofitted 6 to send to UL with the conforming thermostat, and sent the rest to the public with a UL approved stamp on them.

UL was not amused when we uncovered the scam. Neither was the 4 y/o kid with 3rd degree burns.

Great...

Well, since I can't make up my mind between the fire escape ladder with and without the UL mark, I guess that I should just buy both to be safe. When the need arises, I'll drop them out the window side-by-side and use one ladder for the right arm and leg, and other one for my left arm and leg. I should be able to make it to the ground safely this way methinks. <img src="/images/graemlins/wink.gif" alt="" />

Then you would be wondering "Is this twice the safety or twice as dangerous" <img src="/images/graemlins/smile.gif" alt="" />

Nothing like a little doubt to start the day <img src="/images/graemlins/smile.gif" alt="" />

Just one quick comment on the "dive light" remark. I believe that another part of being safe for use in a hazardous environment is that the case itself will not make sparks. If you make a dive light out of stainless steel, it might survive in the water, but might still make sparks if struck against the wrong material.

But then again, all dive lights that I have seen are plastic, which is 100% safe.

Similarly, I'm sure the case needs to be strong enough not to break open when dropped or hit by something hard, thus exposing the electrical components inside.

Actually, this thread is making me rethink what the term "explosion proof" means when describing flashlights. I always assumed that it meant that the light is tough enough to withstand a certain force explosion without breaking, but maybe it actually means the light won't cause an explosion? Anyone have an idea?

I'm pretty sure it is the latter. The idea is you don't want your flashlight causing an explosion. In case of an explosion, the survival of your light is probably not going to be one of your primary concerns! :-)

-john

Considering how fanatical some people on this forum can get about their equipment, I beg to differ! <img src="/images/graemlins/smile.gif" alt="" />