AIMS; BATTNW, BATTELLE NORTHWEST; BNW; CRL, CHARLES RIVER BREEDING LAB; HUFFMAN LAB; IA STATE UNIV; MEI CORP; NATL BUREAU OF STANDARDS; NIH, NATL INST OF HEALTH; PRINCIPALS + METHODS OF TOXICOLOGY; PURINA; SERADYN PARTICLE TECHNOLOGY DIVISION; XYBION MEDICAL SYSTEMS