I have discussed it at length with the USAA insurance people, I expect there are policy documents on their web site. The exact discussion was, "If the source of the fire is tracked back to a leaking gas can or a propane tank we won't cover the loss, we recommend you store flammables in a shed away from your house."

My impression from them was they were very dubious about "off book" uses of things as well, which leads to my expectation that they would push back on covering a loss due to a "home made" battery wall. Could I sue them and get them to cover it? I don't know, perhaps. But, as with my propane tanks, I would keep this stuff out away from the house to limit my losses and avoid having to go there.

I googled "insurance fire caused by gasoline in garage" and found https://cpsc.gov/content/consumers-warned-against-storing-ga... as the third result. "CPSC also warns consumers that private storage of more than a limited amount of gasoline (usually five gallons or less) is illegal in many areas, and subsequent fire damage may not be covered by insurance policies."

although IANAL, storing a large quantity of lithium ion batteries seems likely to be considered negligence, which is generally not covered under insurance.

Here is a quote from my insurance policy (Erie Insurance):

> “We” do not pay for loss resulting directly or indirectly from...the discharge, dispersal, release or escape of any solid, liquid, gaseous or thermal irritant, pollutant or contaminant, including smoke, vapors, soot, fumes, acids, alkalis, chemicals and waste

I checked another insurer (State Farm) and they had similar language:

> We do not insure, however, for loss...caused by...Discharge, dispersal, seepage, migration, release or escape of pollutants...Pollutants means any solid, liquid, gaseous or thermal irritant or contaminant, including smoke, vapor, soot, fumes, acids, alkalis, chemicals and waste

Keep reading the Erie policy. Look for phrases like:

"...into or upon the land, the atmosphere or any course of or body of water, whether above or below ground."

and

"but this exclusion does not apply if such discharge, dispersal, release or escape is sudden and accidental."

I'm pretty confident you will find them, or something similar.

I looked, but I don't see anything like that. The exclusions for smoke and water damage do not apply to "sudden and accidental" losses but the pollution one does. And it does not limit it to contamination of the environment.

My Erie policy was emailed to me, but here is a State Farm policy (not the one I quoted above) that has a similar exclusion:

http://www.opic.texas.gov/images/TDI_Approved_Policy_Forms/S...

That said, from googling I gather that there has been a lot of litigation over what counts as a "pollutant," including specifically whether gasoline counts. So I don't think that the presence of this clause means that an insurance company will always try to exclude any losses involving gasoline. I just think maybe they would have an argument if they wanted to.

Look at page 21 of that document.

"This (pollution) exclusion does not apply to bodily injury or property damage:

... (3) caused by common household chemicals used to maintain the residence premises."

Additionally, and perhaps even more importantly, this exclusion is in the "Personal Liability" section of the policy. The coverage/exclusions for the "Dwelling" are on pages 8-12.

Ah, interesting, I didn't read that to include gasoline but I see how one could argue that it does. The Erie policy has no such language.

In any case, thanks for the responses. My gut reaction is to agree with you that a lot of these "homeowners insurance will deny your claim if you do X!" warnings are based on third-hand knowledge or misinformation. I don't have any special knowledge though. (Do you?)

Edit: oops, you're right of course that I was reading the wrong part of the State Farm document! I swear I am not reading the Erie one so carelessly though.

> I see this blanket assertion in lots of comment threads, but never with a citation.

Imagine a company whose only product is one that if anyone uses, they lose profit. It doesn't take a huge leap of imagination to believe insurance companies will blame literally anything to deny coverage on a house fire.

And imagine if you had a house fire and had your coverage denied. Would you be at all shy of posting those details on a public forum? I'm not saying that denials like this can't/haven't happened, just that I've never seen a first-hand account of such an occurrence (it's always somebody's cousin's co-worker's son).