Document mmkzwYqrGaJqj9VBYqx29MY5k

CH-2 ESTABLISHED1802 E. I. d u Po n t d e Ne mo u r s 51 Co mp a n y INCORPORATED Wil min g t o n , De l a w a r e 19898 CHEMICALS, DYES AND PIGMENTS DEPARTMENT R.A. F.E. S.N. J.B. R.M. M.J. B.C. H.J. J.R. J.R. Fenoglio French Boyd Coleman Salemi Randolph McKusick, CR&D, HL Trochimowicz, CR&D, Gibson, CR&D, HL Barnes, CR&D, HL HL February 8, 1979 J. G. AFTOSMIS CR&D HASKELL LAB CHRONIC INHALATION STUDIES TiO,, AND TiCl, In a meeting at Haskell Lab on January 25, 1979, you raised a question about scheduling the commencement of chamber exposures planned for the chronic inhalation studies on Ti02 and TiCl^ in May. Under consideration was the incomplete 12-month examination of animals from four-week inhalation studies on five coated Ti02 pigment dusts and difficulties in dust generation of the "pure" Ti02. CD & P does not wish to delay this work and requests that Haskell Laboratory proceed on the original schedule to conduct the chronic testing of TiCl, and uncoated Ti02 (99% Ti02 and 1% cooxi dized Al20, without TEA, Haskell #11,564)^as originally planned for MR-2929. If final results from the four-week inhalation studies of MR-2795 indicate that a chronic study is in order on one of the coated TiC>2 materials, we will consider having that work done at a later date! WHD:car WILLIAM H. DARNELL