Had a customer give me a container of gasoline. Its probably several months old. Husband left it in the garage after she kicked him out for cheating.
I don’t want to ruin my equipment engines or my trucks by pouring old gas into their gas tanks.
What should I do with it?
HAZ MAT recycling place is kinda far away.
Call up an auto repair shop that does gas tank repairs and see if they will take it off your hands. Offer to pay a small fee if they are reluctant.
Radiator shops typically do gas tank repairs, but many general repair places will also do it.
Not sure what you mean by HAZ MAT. Many municipalities provide recycling for “household hazardous waste;” you’ll have to Google that term + your city to see what they offer.
Alternative: put a bit of it at a time into your cars/trucks. One gallon diluted by 15+ gallons of fresh gas should run through the vehicle just fine.
Outboard two-strokes might be less sensitive, but I have used gas at least a year old when boating. I add a little less oil than with fresh gas, and it works fine.
Months old should be no problem at all - use it normally.
Your local petrol station should have the means for safe disposal. They will have a sump tank for collecting fuel spillages.
HAZ MAT refers to the facilities that municipalities provide for recycling of hazardous waste. Of course, you could have Googled that term but it would have deprived us all of the irony of your advice. 
Yep. And as another said, if your worried about it. Just put a bit in your tank at a time.
Not sure if this is environmentally friendly, but I suppose that you’re not on a property big enough that you can just burn it? We burn slash/dead tree limbs from our property about twice a year. Often just use some gas and/or diesel to start the fire (yes I know that’s cheating).
This is a pretty good way to use it up. I find very few places take old gas for disposal as opposed to old oil which most garages do take.
The worst thing on the environment is to let it evaporate.
The next best thing is to burn it.
The best thing is to pour it into your car’s gas tank when the tank is empty, and then fill the tank with fresh gas.
Out of curiosity, what do folks here imagine might be the problem with gas that’s months old?
Tastes funny
Gas that sits around loses the lighter, more flamable, hydrocarbons to evaporation and it doesn’t burn as well. If left too long, it’ll end up as varnish, but that’s usually a matter of a year or more, not months. In a few months, it’ll lose some of those light hydrocarbons and could cause problems in an engine. But as said above, mixing with lots of fresh gasoline should avoid any problems.
Pout it on an anthill and set it on fire?
Another problem with old gas is that in the US most gasoline is sold with ethanol mixed in. A nice gift to the large corn producers in the midwest.
That ethanol is hydroscopic. The water can damage some parts of a fuel system, especially cheap lawnmowers and such devices.
I can’t imagine there would be a problem adding the old gas to an automobile that is in regular use, but be careful with motors that aren’t run very often or are very cheaply made.
Yep, I know HAZ MAT is shorthand for hazardous materials. It just wasn’t clear whether OP was talking about household hazardous waste collection services - which are geared toward accepting small quantities of the kinds of things you might find in homes (e.g. paint, gasoline, pesticides), and typically don’t require any sort of paperwork or fees - or some sort of facility designed to accept industrial waste, which might have disposal packaging/transport requirements, fees, paperwork, and/or quantity limits.
Is that bad? One of the advantages of having ethanol in your gasoline is it disolves the water and carries it out, so you don’t gt slugs of water in your engine, or growths in your fuel tank.
???
Almost all gasoline containers are sealed, most newer ones hold pretty good pressure even. Unless it wasn’t closed at all, there’s not going to be much loss of lighter fractions or gain of water in a few months. If it was in an open bucket, sure, it’s useless for anything but setting on fire or cleaning paint/grease (risky).
How bad is it on the environment? I assume we’re talking about a small can of gas for a lawn mower or whatever–maybe 2-3 gallons.
Now I sure wouldn’t want to pour it straight into a stream, or even a river–but evaporation is much more diffuse, I assume.
Is evaporating a small quantity like this more dangerous than putting it in a car and “evaporating” it out the exhaust pipe?
I must admit I do not have a cite for this, but I have heard numerous times over the years that burning gasoline is better on the environment vs. letting it evaporate. (I should have stated this in my original post.) Perhaps someone with more chemistry knowledge than me can chime in on this.