Corrosion Control - Biodegradable Cleaner

Lee Erb, Chap 1000 Det 5, Arlington TX, Chap 34

Originally published April 1997

It has been available since 1994 but I just learned about a biodegradable cleaner that replaces Methyl Ethyl Ketone (MEK), 1,1,1 Trichloroethane, and Toluene. It is a biodegradable, low-volatility solvent substitute for mineral spirits, thinners, and chlorinated solvents. One trade name is "Citra-Safeâ Deodorized." The chemical name is d-Limonene.

After having used it, I believe it would be a good all-around cleaner for the homebuilt aircraft.

Several major aerospace companies have approved it for surface preparation, general solvent cleaning, and cleaning prior to sealing. Even the USAF has approved it in TO 1C-135-2-5-2 for cleaning KC-135 fuel cells. It can be used for cleaning prior to chemical conversion coatings.

The use of Citra-Safe reduces risks of hazardous chemical spills, eliminates most hazardous waste disposal costs, and eliminates the health hazards associated with traditional solvents.

It does not evaporate as fast as other cleaners but 100 percent will evaporate. The flash point is 132 F which makes it still hazardous (140 F and above is "non-hazardous").

It also meets the requirements of MIL-C-81964A as an avionics cleaner. The best information I have is that it will not deteriorate aircraft paints. Be sure to test it yourself.

If you get it in an eye you still use the standard Boy Scout treatment of flushing with water for at least 15 minutes. A person does need to treat it like any solvent and not get careless. If you use it, be sure you have read the MSDS (Material Safety Data Sheet) thoroughly.

I have used it without rubber gloves but it tends to dry out my hands. Although it is not water soluble, soap and water will wash it off your skin.

It has a slight odor of oranges. I have been told that before it was "deodorized" that it could make you never want an orange or orange juice.

One source is Inland Technology Products and Services, 1 (800) 552-3100. Eric Lethe was very helpful in providing information. Web Site, e-mail They are set up to respond to industrial orders with the smallest container is a gallon in 6-gallon cases at about $300.

The stuff is good. With industry being hounded by OSHA and EPA, I'd say it was the proverbial "God-Send" for industry. Maybe there will be enough demand for it in the future that someone will make it available in spray bottles. I cleaned a lot of parts with just a small part of a spray bottle.

Thanks to Dave Ragsdale for introducing me to the biodegradable cleaner with versatility.

Biodegradable Cleaner Source

Russ Erb

Originally published May 1997

While cruising around Harbor Freight in Lancaster recently, I stumbled across what appeared to be the biodegradable cleaner mentioned in The Leading Edge last month. Why they put that pallet in the middle of the aisle I don't know. I picked myself up and noted it was labeled BioSolv Parts Cleaner, in 2.5 gallon jugs for about $25 apiece. That equates to $10 a gallon, much better than the $50 a gallon in 6 gallon lots mentioned last month. I could not find anything on the label that specifically identified it as d-Limonene, but it did say that it was derived from citrus and it did have the faint smell of oranges. While I find OSHA and EPA to usually be more harassing than helpful, I'd feel better having this stuff in the garage than MEK or other hazardous petroleum products.

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Revised -- 20 December 1997