How To Dispose of Linseed Oil Rags Safely

Littering is a crime and carries a financial penalty if caught.  While that is pretty bad, it’s not as bad as littering with or the improper disposal of oil-soaked rags.  That’s because while the former is an eyesore, a discourtesy, and ugly, the latter is outright dangerous.  

Key Points:

  • All oil-soaked rags and paper towels are fire hazardous
  • They need to be treated as hazardous wastes and disposed of properly
  • If not disposed of properly, you run the risk of a spontaneous combustion fire that could bring down your workshop, garage, or house.

We’ve even written about the safe disposal of oily rags, as well as polyurethane rags, and generally, about disposing of rags and paper towels you’ve used either to apply wood finishes or to wipe off excess oils and other wood finishes.  You’ll find it addressed in a previous article we wrote about linseed oil, in particular, but also applicable to all oil-based finishes.

The science is not difficult to understand, and the steps needed for the proper disposal of oily materials are not difficult and require no special tools or equipment.  Think about the types of projects you take on in your woodworking shop and how most, if not all, of them, involve the use of some wood finish.  

They might include:

  • oil-based paints on your kitchen cabinet project
  • staining furniture, or like me, staining a new deck out back in the garden
  • using any other oil-based products in the course of your work, including primers, paints, paint thinners, turpentine, denatured alcohol

They all have something in common:  they are all combustible, and you run the risk of spontaneous combustion fires if you are not careful and do not exercise proper methods.

Linseed Oil In Particular

All oil-soaked rags are a danger, but linseed oil, in particular, is more likely than other oils to self-ignite.  Whether you’ve used a rag to apply linseed oil or used a rag to clean up spills, or simply wiped linseed oil off tools with a rag, those rags are dangerous, and you need to treat them as such.

Linseed oil rags can go to the top of the list, though, as they can and sometimes do burst into flames.

Oils are combustible.  We know this, all of us, whether it’s watching an ocean aflame from oil spills or an oil truck exploding in a movie.  But, closer to home, we have those same products in our woodworking shop, and we have to be aware of their danger.

The rags we use in our work get soaked with some oil-based product, and in this case, we are discussing linseed oil in particular.  Heat and energy are released when they are compacted in a tight space because we rolled them up and through them in the corner of the shop or in a trash can. 

The compaction and tight space in the trash can insulate the pile; the energy and heat build and cannot dissipate fast enough; temperatures rise; suddenly, this chemical reaction will cause the rag to bust into flames.  The drying and oxidation process, that chemical reaction that leads to the buildup of heat, can easily lead to a fire.  This needs no external flame or heat from the immediate surroundings.

How To Properly Dispose of Linseed Oil Rags

As we have said, don’t simply throw the rags in the corner or in the trash can with other shop debris, much of which will also be combustible.  There is a simple rule to remember and follow when you’re done with the rags, and no special equipment is necessary.

In that earlier article on the subject, we suggested laying the rags out on your driveway, in the backyard, or on the garage floor to let them dry.  Don’t rush things with them; let them dry fully.  Spreading them out rather than rolled up in a ball will allow the dissipation of heat in that chemical reaction. 

When they are completely dry, soak them, this time with water.  Use your hose, for instance, or put them in a bucket of water.  Get them fully soaked. Linseed oil rags in water can’t burn.

Don’t squeeze the water out.  Rather, put them in a can, maybe an old coffee can, or in a plastic bag, and put the lid on or seal the bag.  Most towns and cities have a hazardous waste disposal area or facility, and that’s where they belong after that.  If you use a waste collection company to haul your trash, they can take the rags in the can or bag for you and dispose of them properly for you.

UL Safety-Certified Container

Underwriters Laboratory (UL) certifies oily rag metal containers.  These metal containers are rated by UL to be a safe means of disposing of the rags.  Oily waste containers can be found at the big DIY stores, your local hardware stores, and from online retailers.  They can run from around $60 up to a couple of hundred dollars, depending on the size.  

If yours is an occasional thing only, go with the dry/dunk method; but if you are generating a lot of oily rags, you might want to invest in a UL-rated oily rag metal container.  It is your shop, your garage, your home, and your life that could be at risk if you are careless.

Video Proof of Spontaneous Combustion

The National Fire Protection Association reports that each year an average of 900 fires are caused by oily rag combustion, and an average of 1700 house fires are caused by spontaneous combustion or chemical reactions like the ones we’ve been discussing.  

Still don’t believe it?  Watch this video, then. 

Be safe.  Dry the rags out.  Soak them in water.  Seal them and dispose of them at a hazardous waste disposal center, or ask your trash hauler to bring them to a hazardous waste disposal center the next time they come.  Of, pony up a few dollars for safety reasons and purchase an oily rag metal container.

Linseed oil rags are no joke and need to be taken seriously.  Your life and your home are at risk if you don’t.

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