I have some old bug spray that must be 8 years old. It is 99% deet. I think it is Deep Woods Off but I am not sure. The reason it lasted so long is that I hardly ever use it. I carry it in the BWCAW just for emergency situations or when I am stuck doing a chore during that peak mosquito period before the sunset. Is this bottle still effective or should I throw it out?

I hope it is still good, my bottle is that old also and I'm taking it.

That is a really good question. I'm interested to know the answer too.

I think it's worth the weight of a new bottle to bring along in case the old one doesn't work next trip. Plus, you'd be educating all of us on the effective shelf-life of deet! :)

I'm still using a stash of 75% GI surplus DEET I purchased in the early 1970s. Good as new.

How about storage temperature? I have bottles in glove boxes and tackle boxes that probably have been cooked and frozen. Not sure how well it works because I avoid using it.

Is it in a pump or aerosol can? I would expect mechanical failure of the can or pump to go first. Don't know. ?
This is an interesting question. Can you contact the manufacturer?
To hijack the topic for just a moment, I remember reading an article once (don't remember the source) that anything greater than 30% deet is unnecessarily exposing yourself to the toxic effects of deet. IT has no further efficacy beyond 30%. I had several bottles of 100% deet from REI that I tossed after unsuccessfully trying to dilute it with several different solvents. Sorry if this is an inappropriate departure on the subject. Should this be a new subject?

Mine are little bottles and I'm more worried about them breaking and eating the plastic it comes in touch with. I think I have a ruined tackle box tray from a deet leak. Never thought of diluting the stuff though.

quote jaimed: "Is it in a pump or aerosol can? I would expect mechanical failure of the can or pump to go first. Don't know. ?
This is an interesting question. Can you contact the manufacturer?
To hijack the topic for just a moment, I remember reading an article once (don't remember the source) that anything greater than 30% deet is unnecessarily exposing yourself to the toxic effects of deet. IT has no further efficacy beyond 30%. I had several bottles of 100% deet from REI that I tossed after unsuccessfully trying to dilute it with several different solvents. Sorry if this is an inappropriate departure on the subject. Should this be a new subject?"

I don't think your post falls into the "hijacked" category in the least bit. The percentage of deet within the bug spray is well within the topic at hand. I have often wondered why manufacturers started making bug spray with less and less deet over the years which is exactly why I am hording my 8 year old bottle of 99% deet in the first place. So you see, your comments are actually quite on-topic and very insightful.

Now if you would have made a comment about how bug spray is a cheaper alternative to bear repellent spray, then that would have been a hijack.

I found this on the internet so it must be true...
How many years does a DEET repellent remain effective? What is the shelf life of DEET?

DEET is very stable and is effective indefinitely as a repellent. For this reason, the federal government doesn't require an expiration date on product labels. But manufacturers of repellents say that the feel, smell and appearance of their products may change after about three years. This does not reduce the DEET's ability to repel mosquitoes and ticks but may make the product less appealing to users. If you're not sure about your particular product, contact the manufacturer. Any other questions about DEET-based products, you can call us at 1-888-NO-BITES (662-4837).

quote DuluthPak: "

quote jaimed: "Is it in a pump or aerosol can? I would expect mechanical failure of the can or pump to go first. Don't know. ?
This is an interesting question. Can you contact the manufacturer?
To hijack the topic for just a moment, I remember reading an article once (don't remember the source) that anything greater than 30% deet is unnecessarily exposing yourself to the toxic effects of deet. IT has no further efficacy beyond 30%. I had several bottles of 100% deet from REI that I tossed after unsuccessfully trying to dilute it with several different solvents. Sorry if this is an inappropriate departure on the subject. Should this be a new subject?"

I don't think your post falls into the "hijacked" category in the least bit. The percentage of deet within the bug spray is well within the topic at hand. I have often wondered why manufacturers started making bug spray with less and less deet over the years which is exactly why I am hording my 8 year old bottle of 99% deet in the first place. So you see, your comments are actually quite on-topic and very insightful.


Now if you would have made a comment about how bug spray is a cheaper alternative to bear repellent spray, then that would have been a hijack."

I remember several years ago seeing deaths of young children associated with high concentrations of deet. Maybe that's the reason????haven't seen any reports of that happening for some time now.

Dave

I had some 3M Ultrathon lotion that sort separated and became pretty much unusable. You could not remix it. It was the lotion part that broke down I'm sure. Not positive how old, at least two years. My mainstay is the Deep Woods OFF pump and I've never noticed and degradation with that. I must have used stuff several years old.

You have to fill a plexiglass box with 1 million mosquito's and then spray your arm with the product in question and then stick it in the box of Mosquito's. That is how they did it when I was a kid.
:) (REALLY it must be true it was on TV)
SunCatcher

How strong is the shelf?