Document RpKwM6mZaNoa9dv8xRwyxDjpn

FOR D PONT USE ONLY AR226-2902 E. I. du Pont de Nemours and Company Haskell Laboratory for Toxicology and Industrial Medicine Elkton Road, Newark, Delaware 19711 HASKELL LABORATORY REPORT NO. 306-81 MR NO Study Initlated/Completed 4/27/81 - 5/15/81 Material Submitted by roxymer rroaucts Department ESL 269/306 INHALATION MEDIAN LETHAL CONCENTRATION (LC50) Procedure: Male albino Crl:CD rats were housed In pairs in 8" x 8" x 14" stainless steel wire mesh cages* Purina Certified Rodent Chow #5002 and water were available ad libitum. Rats were weighed and observed for general suitability for 1 week prior to testing. Groups of 10 rats, weighing between 241 and 298 grams, were placed wire mesh restrainers ^^^exnosed^head^only^for^toigle 4-hour periods to atmospheres c o n t a i n i n g V | | f H H H | H P j j | P f l | ^ H i All rats were weighed and observed daily (except weekends) for 14 days post exposure. Generation: Dust atmospheres ofl Iwere generated by passing air through a single-stage, glass, cyclone generator which contained the test material. An electric motor and steel rod with plastic paddles agitated dust in the generator. Additional houseline air introduced at the top of the generation apparatus carried airborne dust into the exposure chamber. Analytical: Samples of chamber atmosphere were collected at 30-mlnute intervals. Calibrated volumes of atmosphere were drawn through preweighed Gelman glass fiber filters (Type AE 25 mm). The atmospheric concentration of test material was determined from weight gain of the filters. Particle size 1 Company Sanitized. Does not contain TSC CBI (mass median diameter) was determined with a Sierra Cascade Impactor during one exposure. Results and Discussion; No deaths occurred as a result o ^ e xposure to ~ atmospheric concentrations high as mg/L, the highest concentration which could be generated under these test Concentration mg/L Mean S.D. Range - - - - - - - TS5Maas Median Diameter 9.6 6.7 3.0 - 23 5 3.1 9.0 - 19 Fractional Mortality (g Deaths/# Expos'-d) 0/10 0/10 On the basis of the single particle size analysis, it was calculated that approximately 18Z of the reported concentrations were particles of respirable size. The mass median diameter of that fraction was approximately 1 micron. Consequently, the concentration of inhalable particulates in these atmospheres may be more appropriately exoressed as 1.7 and 2.7 mg/L. ^Ttius, since no mortality occurred, the LC50 ol^^_-------- -- expressed in terms of respirable particles is greater than 2.7 "SfObservations: Observations could not be made during exposures due to the ^ denseness the dust atmospheres. Rats at both test levels shoved a severe weight loss 24 hours post-exposure followed by weight gain. Observations in the8first 72 hours included yellow-stained perineal area, dried red ocular discharge, and brown-stained nose and mouth. Several rats had brown-stained fur throughout the observation period. One rat exposed to 15 mg/L had a cloudy eye beginning on the 10th day post exposure. Summary Groups of 10 maleXrl:CD rats were exposed to dust atmospheres or ---------------'or single, 4-hour periods. An LC50 could not oe determined since no deatfis resulted from exposure to concentrations of 9.6 or 15 mg/L, the latter being the highest concentration which could be generated under these experimental conditions. Since approximately 1 M of the concentrations reported were particles of respirable size, the LC50 of this material expressed in terms of respirable particles is greater tha. mg/L. Company Sanitized. Does not eontain TSC CB! * Purity: 1 Work and Report by: Robert Turner Technician Reviewed Juayanne L. Ferenz S j v Toxicologist RT:jrg:WP:3.5 .Date Issued: July 29. Report Wo Approved by: ____ ______________________________ Gerald L. Kennaoy Chief, Acute Investigations Section - 3- Company Sanitized. Does not ceiuain T S C A C ii