Open main menu

3M Lite Loft Thinsulate odor and half life?

I have a sleeping bag from the 90s made with 3M Lite Loft Thinsulate.  It was once a 0 degree bag, but it's probably good to only 40 degrees now.  That's not a problem.  I got my money's worth.  I hadn't used it for a few years, so it was hanging in a closet.  I pulled it out the other day and got in it to check for sizing for another bag.  There's a somewhat strong chemical-like smell coming off it.  No mold.  No mildew.  I washed and low-heat dried it after the last season of use.  My assumption is the fibers, or bonds between the fibers, are breaking down and creating this odor.  Like I say, this is a chemically smell.  It's not bad enough to not use the bag, but 1)  is it safe to continue using it?  2)  am I right in the assumption that the Lite Loft is breaking down and creating this smell?

Has anyone read anything like or about this?  Is this to be expected with older synthetic versions?  Thanks for any information, experiences, or links that can help explain what I think is happening here.

Never heard of such things. I suppose that if you can rule out glues or coatings delaminating--that is, if the bag is constructed using regular old thread and the fabric is plain nylon--the only thing left is the insulation itself. Perhaps some sort of reaction with the detergent you last used?

I suppose it could be the detergent.  I've always used scent free and been conservative with amounts with extra rinses, especially with my camping gear.  I've never cared for colognes, perfumes, or scents.  I've been a real stickler for smells since I was a kid. There's no coatings on this bag.  Insulation, rip stop nylon, and polyester threading.

By chemical if you mean a plastic smell similar nylon, it may just be the fabric odor that has collected within the fill over time, that is released when you jostle the bag around.  Fluffing the bad to replace that stale air will lessen the smell.  Additional use and fluffing will make the scent eventually dissipate.  But do check the bottom of the bag for a possible dead rat ;)

On a related vein: Some synthetics will degrade over time if store near electrical motors or where exposed to UV rays.


This is not a nylon odor.

I guess the good news is that this isn't common or known.  Who knows?  I think I'll give it another light wash and line dry it in our windy spring season.  Can't hurt.  Thanks for the feedback.

The insulation itself is 100% polyester, which is a remarkably stable polymer. I can't find any literature demonstrating decomposition over time in an ordinary environment - and most of the common decomposition byproducts wouldn't have a strong smell.  There my be a polyurethane coating on the inside of the bag - that can have a rather objectionable odor over time. I'm with Ed here - probably ordinary funkyness compounded by time. Air it out in a warm room to see if that helps. You might try enclosing it in a trash bag with a sock filled with baking soda - a method that's helped me a few times.

October 23, 2020
Quick Reply

Please sign in to reply