The Transportation Security Administration (TSA) has purchased 1,250 test kits for $185,000 from Mistral Security to screen powdered substances for explosives at aviation checkpoints nationwide, adding another layer of security. While airline passengers are not prohibited from carrying-on common powders, chemical powders can be used to make improvised explosive devices. As a passenger’s carry-on items are passed through an X-Ray machine, if the Transportation Security Officer determines that a secondary screening is necessary, another officer will take a sample by pouring a small amount onto a test strip and put a solution on it. The solution will indicate wither the substance is harmful or not. TSA says the “vast majority” of powders such as medication, baby formula and makeup, are unlikely to need additional screening. Mistral Security is part of Maryland-based Mistral Group. The test kits were pilot tested in 2008.