In an effort to protect soldiers from this threat, the U.S. Department of Defense has been seeking a solution that Lochhead initially regarded as an impossibility: a material that soldiers could smear on their faces like suntan lotion, leaving a coating that although thinner than a sheet of paper, could protect against that intense heat…
The new camouflage makeup protects the face and hands for up to 15 seconds before its own temperature rises to the point where a first-degree burn, which is a mild burn, might occur. In some tests, the new face paint can protect for up to 60 seconds, which could be important in giving soldiers time to move away from blast-related fires and also for use by civilian firefighters.
The makeup had to meet several key criteria: it had to reflect intense heat; have camouflage colors suitable for day and night use; be easy to apply and remove; be waterproof; and be non-irritating to the eyes, nose and mouth.
The trickiest part was that the …team had to avoid the use of mineral oil, mineral spirits, fatty substances and other traditional hydrocarbon makeup ingredients. Hydrocarbons can burn in contact with intense heat in the flame spectrum.
The team turned to silicones, which are not as flammable because they absorb radiation at wavelengths outside of the intense heat spectrum. Silicones have been replacing hydrocarbons in many commercial cosmetic makeup products as cosmetics companies improve products to confer better feel properties and transfer-resistance.
Another challenge was adding DEET, an insect repellent. The military mandates that all camouflage makeups contain 35 percent DEET. “DEET also is flammable, so when the Department of Defense asked us to incorporate it, we didn’t think we could do it,” Lochhead notes. But the team successfully included DEET by encapsulating it in a hydrogel substance, a water-rich material that prevented DEET from catching fire.
It already has passed the preliminary laboratory tests needed to determine whether development should continue. Lochhead’s team also plans tests of the material on other surfaces to try to protect clothing, tents and other items from burning, and a colorless version is being developed for firefighters.