The U.S. National Institute of Standards and Technology says it has created a new trace explosives standard designed for homeland security use.

Officials said the new standard consists of four different test substances designed to simulate trace residues of C-4 plastic, gunpowder and TNT explosives.

NIST officials said the standard will be used by security personnel to find explosive materials and people who have been in contact with them.

The new certified reference material is compatible with field and laboratory assay methods and will be helpful in calibrating, testing and developing standard best-operating procedures for trace-explosives detectors, NIST officials said.

The creation of the new reference material is part of a larger, ongoing project to develop other wet and dry materials that simulate gunpowder, peroxide and other types of explosives. Officials said efforts also are under way to develop reference materials to help train bomb-sniffing dogs.