I purchased a house that has a garage floor that is soaked with car chemic#als. It looks like a car mechanic worked in the garage and just let everything spill on the floor for 30 years and never attempted to clean up any spills. The floor makes the garage smell toxic and anything that touches the floor takes on the very offensive smell. I have tried every cleaner formulated to for the purpose of cleaning a concrete garage floor and lots of home solutions too, like Dawn soap, and nothing removes anything from the concrete. I know acetone is harsh and not a first choice because of the fumes and because it will make the concrete more porous, but I have to remove the toxic chemicals from my garage floor. I know concrete pools that are stained are cleaned with acetone so that is where I got the idea. My concern is the safety of acetone mixing with car chemicals like oil, gasoline, transmission fluid, brake fluid, etc. I want to be certain not to cause an explosive chemical reaction or a fire. So, is it safe to use acetone to remove the chemicals from my concrete garage floor?
The short answer is that you will not be able to remove embedded hydrocarbon residues from the cement pad. That is because it is a combination of the structure and the chemistry, as well as the different types of compounds that may be in there. You don’t really know how much is contained in the concrete or what kinds of compounds they are. You may or may not be able to remove the lighter compounds that produce most of the odor, but that may also be temporary as others continue to diffuse out. Acetone is not an “universal solvent” either, and may not even dissolve some of the offending compounds. As you noted, use of sufficient quanitities of acetone would present its own safety and hygiene problems.
The only real and permanent solution is to have the cement ground down, cut out, or entirely replaced by new concrete. Before going to that extreme there are two other things that you can try. The first is to apply a thick epoxy paint layer over it. I used that coating in a laboratory floor years ago and it held up quite well. Coating the cement floor with the epoxy should form a barrier to the odiferous compounds, and the colors available will cover the spill stains.
The second option would be to simply add another layer of concrete on top of the old pad. That may be more durable than the epoxy paint and should encapsulate the offending compounds in the lower layers.
This is a good example of the necessity of making a thorough examination of a property before purchase. There are many places in a structure that can hide previous neglect, poor construction, or excessive wear or pest infiltration.
Ann - Steve has some good advice. What I can add is that working in that garage will probably expose you to toxic fumes from whatever was spilled there, and you should not spend any appreciable time in the garage. You might want to consider hiring a professional industrial clean-up company. It would be expensive, but they would have the proper personal protective equipment to do the job safely. And it might be less expensive than to tear up and replace the garage floor; you should get quotes from companies that offer either service. As for using acetone, you should not not not do that, because you'll be adding another hazard to the mix. In addition to its own toxicity, acetone is extremely flammable and even explosive all by itself, so using it in an enclosed space like a garage is not something you want to do.
The epoxy is a good idea, but it may not adhere well if the concrete is really saturated with grease. I would experiment with a small section of the concrete to see if methylene chloride, chloroform, or perchloroethylene (probably the easiest to obtain) will remove the bulk of the hydrocarbon mess. If it does, only work on small sections of the floor at one time to avoid prolonged breathing of the solvent. I agree with Howard that acetone is definitely not a good idea because of toxicity, flammability, and the inability to dissolve many hydrocarbons. Perhaps before trying any solvents you may try steam.
Geez! It is no no no to use Acetone. Try using an at least 4,000 psi water pressure machine to remove any chemical residues from concrete. I believe it will work. Hope this helps.
Rafeal is right! Acetone's flashpoint is below zero degrees (either scale). Using acetone in this manner might solve the problem, but you'll be rebuilding the house after the fire. Professionals might shun the problem, too, so I'd use laundry detergent and high pressure water and maybe steam. If you can get it cleaned up to unsightly, with low odor, try epoxy finishes on patches of the worst...let them sit through a summer and winter. If it holds, it could provide a pretty good mask of the problem. Good luck.
I used to own/operate a small business that used pressure washing with various additives and dry ice blasting as superior cleaning methods. A decent pressure washer doesn't really cost that much - and many can be rented as well. Using a pressure water wash with liquid soap additive will pretty much clean up everything.
Dear Ann, you already got a few great suggestions. Here is one more environmentally friendly approach. I would try to remove the tough stains physically as much as possible before dissolving with chemicals. From my experience helping my husband who’s really into construction, baking soda has been great with weakening chemical bonds. Then using hydrogen peroxide or vinegar produces gaseous molecules that can reach into porous space before forever gone with nasty odors. Don’t forget to have a good ventilation!
Try using kitty litter, the large chunky kind, not the sandy clumping kind. We have always used it to absorb oil spills on cement. Spread it out, let it sit a while, and then move it back and forth over the area with a push broom. It works well and may work even better if combined with some of the other suggested methods above to loosen it up first. The kitty litter can be swept up easily afterward.
I was able to remove a old-large oil stain on my driveway. I first covered the area with clay and ground it into the concrete with a brick. I used cheap kitty litter that showed the contents as clay. I would let it sit for several days, sweep it up and reapply. This will remove a majority of the components and significantly improve the air quality. After a couple of weeks of using the clay, I applied Purple Power degreaser. This will dissolve and lift out the remaining oil and fluids. I used a wire brush to remove the stubborn stains. You will need to wear goggles, long sleeves and gloves with this degreaser. The oil spot is completely gone.