On a For Your Information (FYI) basis, the Monsanto Company submitted information concerning the conduct and preliminary findings from a recently completed intrapleural implantation study of calcium sodium metaphosphate (CAS No. 23209- 59-8) fibers in rats: 'In this test,. . .(calcium sodium metaphosphate) fibers in gelatin pledgets were surgically implanted in the pleural space of experimental rats. Each of 3 groups consisted of approximately 75 males and 75 females at the outset; sub-groups of 5 males and 5 females from each group were sacrificed at 6, 12, and 18 month inter- vals. No (calcium sodium metaphosphate) fiber-induced fibrosarcomas were detected at these interim periods. After the final sacrifice at 24 months, 3 of the 120 (calcium sodium metaphosphate fiber-exposed) animals had fibrosarcomas. Also, at the final sacrifice in the positive control group, in which chrysotile asbestos had been implanted, 5 of 121 animals had fibrosarcomas. In the negative control group, no fibrosarcomas were ob- served.'