Document MMOQR7xq0LyO4eEGpzXv4K56j
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A226. 3239
DuPontsets
`TRADE SECRET
'H-24678:
Study Title
Inhalation Rats Approximate Lethal Concentration (ALC) in
Laboratory Project ID: DuPont-8684
AUTHOR: John R. Bamberger, M.A.
STUDY COMPLETED ON: April 5, 2002
"PERFORMING LABORATORY: E.L du Pont de Nemours and Company Haskell Laboratory for Health and Environmental Sciences
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124678 Inhalaion Approximate Lethal Concenation (ALC) in Rats
Dupontsess
CERTIFICATION
We, the undersigned, declare that this report provides an accurate evaluation of data obtained
from this study.
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124678: Inhtsion Approximate Lethal Concenaton (ALC) i Ras
STUDY INFORMATION
Substance esc WEA
snonmsCoses:(NAD
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Haskell Number; 24678
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Physical Characteristics: Amber brown liquid
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Stability: Tcohneditteitonssubosfttahnecestaupdpyeanroedevtidbeencsetaobfleinusntdabeirlitthyewas
observed.
Sponsor: EL du Pont de Nemours and Company WUiSlmAington, Delaware 1989
Study Intiated/Completed: November 28, 2001 / (see report cover page)
In-Life Iniisted/Completed: November 29, 2001 /December 27, 2001
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124678: Ihalion Approimte Lethal Concenation (ALC) in Rats
Dupont868
STUDY PERSONNEL
Study Director:
Management:
Primary Technician:
John R. Bamberger, M.A.
Arthur J, O'Neill, B.S. Scott E. Loveless, Ph.D. Janice L. Connell, M.S., B.A., CLH.
Christine B. Skoranski
Pathologist: John F. Hansen, D.V.M., Ph.D.
Management: Steven R. Frame, D.V.M., Ph.D.
Toxicology Report Preparation: Maryanne M. Wilford, B.A. Laboratory Veterinarian: William Singleton, D.V.M., ACLAM.
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H-24675: Inhalation Approximate Lethal Concentration (ALC) in Rats
DuPont8684
SUMMARY
4`T-hhroeuergpreoruiposdotfo 6aemraolsoelCsrolf:HC-D24(6S7D8)IiGnaSirBaRt rcaotnsceeantcrhatwieornes eoxfp2o3s,ed57n,oosre-1o2n0lymgfo/ram?s(idnrgyle, weight). Test atmospheres were generated by atomization, and concentrations of H-24678 were `measured gravimetrically. Rats were weighed and observed for clinical signs of toxicity during a 14-day recovery period. Surviving rats from the 57 mg/m? group underwent pathological evaluation at the end of the recovery period. `The mass median aerodynamic diameters for the aerosol tested ranged from 13 to 1.8 ym. Rats died following exposure to H-24678 at concentrations of 57 mg/m? or greater; deaths occurred within 1 day of exposure. Clinical signs of toxicity noted during the study included a diminished response to an auditory stimulus in rats during exposure to 57 or 120 mg/m. In addition, rats exposed at 120 mg/m? exhibited lethargy, lung noise, and labored breathing immediately following the exposure. One rat exposed at 23 mg/m? exhibited slight body-weight loss within 1 day of exposure (2.1% of pre-exposure body weight) but begantro egain weight by test day 2. Rats exposed at 57 mg/m? exhibited slight to moderate body-weight losses within 2 days of exposure (3.1 to 14% of pre-exposure body weight) but began to regain weight by test day 3.
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Under the
57 mg/m'.
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be
extremely toxic (ALC less than 0.08 mg/L) in male rats.
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124675: Inhalation Approximate Lethal Concentration (ALC) in Rats
Duo 8684
INTRODUCTION `The objective of this study was to determine a 4-hour inhalation approximate lethal concentration (ALC) of H-24678 in male rats. The ALC is defined as the lowest atmospheric concentration tested which caused the death of 1ormore exposed rats either on the day of exposure or within at least 14 days following exposure. The inhalation route of exposure was chosen based on the expected route of potential human exposure and was requested by the sponsor.
MATERIALS AND METHODS
A. Test Substance The test substance, H-24678, was supplied by the sponsoras an amber brown liquid. The test substance was assumed to be stable throughout the exposure phase of the study; no evidence of instability was observed.
B. Animals `Young adult, male Crl:CD(SD)IGS BR rats were received from Charles River Laboratories, Inc., Raleigh, North Carolina. The rats were approximatel7y weeks old on the dayofarrival Rats have historically been used in safety evaluation studies for inhalation toxicity testing. The
Crl:CD(SD)IGS BR rat was selected based on consistently acceptable health status and on
extensive experience with the strain at Haskell Laboratory.
C. Animal Husbandry 1. Quarantine and Animal Selection
Rats were quarantined after arrival for approximately 1 week prior to testing. During the quarantine period, rats were weighed and observed for clinical signs of disease 3 times. Rats were obtained from the general population of stock rats released from quarantine and were selected for use on this study from those rats exhibiting a normal pattem of weight gain and no overt signs of disease.
2 Housing Rats were housed either singly or in pairs in stainless steel, wire-mesh cages suspended above. cage boards.
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1.24675: Inhalation Approximate Lethal Concentration (ALC) n Rats
Dupont8684
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3. Animal Room Environment
Animal rooms were maintained on a timer-controlled, 12-hour light/12-hour dark cycle.
`Environmental conditions of the rooms were targeted to be within a temperature range of
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4. Identification
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`markers so that individual rats could be identified after exposure.
5. Feed and Water
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6. Health Monitoring Program
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those that would be expected to impact the scientific integrity of the study:
+ aWnadteorthsearmcpolnetsamarienaanntaslyzed for total bacterial counts, and the presence of coliforms, lead,
Feed samples are analyzed for total bacterial, spore, and fungal counts.
+ Samples from freshly washed cages and cage racks are analyzed to ensure adequate sanitation by the cagewashers.
Certified animal feed is used, guaranteed by the manufacturer to meet specified nutritional requirements and not to exceed stated maximum concentrations of key contaminants, including specified heavy metals, aflatoxin, chlorinated hydrocarbons, and organophosphates. The presence of these contaminants below the maximum concentration stated by the manufacturer would not be expected to impact the integrity of the study.
`The animal health and environmental monitoring program is administered by the attending
laboratory animal veterinarian. Evaluation of these data did not indicate any conditions that
affected the validity of the study.
D. Study Design
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`Three groupsof 6 male rats each were exposed to aerosol atmospheres of H-24678 in air. Rats
were exposed nose-only foar single, 4-hour period.
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24676: Inhalstion Approximate Lethal Concentration (ALC) in Rats
DuPont8684
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Rats were approximately 8 or 9 weeks old and weighed between 211 and 316 grams at the time
of exposure.
Rats were observed for mortality and response to alerting stimuli during each exposure and observed for mortality and clinical signs of toxicity immediately after they were removed from the restrainers following exposure. During a 14-day postexposure period, all surviving rats were observed each day for mortality,andwere weighed and observed for clinical signs of toxicity daily until weight gains were observed then once weekly thereafter. At the end of the recovery period, all surviving rats were sacrificed by carbon dioxide asphyxiation. Three rats from the. 57 mg/m group underwent a gross pathology examination. Tissues were taken from these 3 rats and further processed for microscopic pathology examination.
E. Inhalation Exposure System
1. Aunosphere Generation
Chamber atmospheres were generated by atomization of the test substance in air with a Spraying
Systems Nebulizer. The test substance was metered into the nebulizer with a Harvard Apparatus
`model 22 Syringe Infusion Pump. Filtered, high-pressure air, metered into the nebulizer by a
Brooks model 1355 Sho-Rate Rotometer, carried the resulting atmosphere into the exposure:
chamber. Chamber concentrations of test substance were controlled by varying the test substance
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feed rate to the atmosphere generator.
Test atmospheres were exhausted through a dry-ice cold trap followed by an MSA charcoal/HEPA filter cartridge prior to discharge into the fume hood
2. Chamber Construction and Design
`The exposure chamber was constructedof glass (cylindrical) with a nominal intemal volume of 29L. A polycarbonate baffle inside the chamber promoted uniform chamber distribution of the test atmosphere.
3. Exposure Mode
During exposure, rats were individually restrained in perforated stainless steel cylinders with conical nose pieces. `The restrainers were inserted into a polymethylmethacrylate faceplate which was attached to the exposure chamberso that only the nose of each rat extended into the chamber.
F. Characterization of Chamber Atmosphere 1. Test Substance Sampling and Analysis
--- "The atmospheric concentration of H-24678 was determined by gravimetric analysis at approximately 30-minute intervals during each exposure. Known volumes of chamber
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1.24678: Inhalation Approximate Lethal Concentration (ALC) in Ras
DuPont 8684
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atmosphere were drawn from the sampling port through a 25 mim filer cassette that contained a
pre-weighed Gelman glass fiber (Type A/E) filter. The filters were weighed on a Cahn model
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A sample to determine particle size distribution (mass median aerodynamic diameter and percent particles less than 10 um diameter) was taken during each exposure with a Sierra Series 210
Cyclone Preseparator/Cascade Impactor and Sierra Series 110 Constant Flow Air Sampler."
2. Environmental Monitoring
Chamber airflow was set at the beginning of each exposure to achieve at least 12 air changes per hour. The airflow was monitored continually with acalibrated Brooks model 1355 Sho-Rate Rotometer and recorded initially and whenever changes were made during the exposure. Chamber airflow was inadvertently not recorded during the 23 or 120 mg/m? exposures. Chamber temperature was targeted at 22. 2C. The temperature was monitored continually with a glass alcohol thermometer and recorded 4 times during each exposure. Chamber relative humidity was targeted at 50 + 10%. The relative humidity was measured with an Omega model RHS100C Digital Psychrometer and recorded 3 times during each exposure. Chamber oxygen concentration was targeted to be at least 19%. The oxygen concentration was measured with a Biosystems model 3100R Oxygen Analyzer and recorded 3 times during each exposure.
G. Anatomic Pathology Evaluation `The 3 surviving animals in the 57 mg/m group had the lungs, trachea, pharynx/larynx, and nose grossly examined at sacrifice. In addition, th tissues from these rats were processed for histology and microscopically examined.
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H-24678: Inhalation Approximate Lethal Concentration (ALC) in Rats
DuPont 8684
RESULTS AND DISCUSSION
A. Exposure Conditions (Table 1)
Animals were exposed to H-24678 at concentrations of 23, 57, or 120 mg/m'. The. concentrations reported are based on the solids component of the test substance. The solvent `component of the test substance was measured by gas chromatography during each exposure `The mean concentration of solvent measured during the study was less than 53 ppm. This concentration is negligible compared to the reported acute inhalation toxicity of the solvent. Therefore, the concentrations reported do not include the solvent component of the test substance. The atmospheres generated in this study were considered to be respirable in rats, as the mass median aerodynamic diameters (MMAD) ranged from 1.3 to 1.8 pm.
Chamber temperature ranged from 22 to 23C, chamber relative humidity ranged from 40 to 45%, chamber airflow was 20 L/min, and the oxygen concentration was 21%. Chamber airflow `was inadvertently not recorded during the 23 or 120 mg/m? exposures.
-- B. Mortality, Clinical Signs, and Body Weights Deaths occurred at concentrations of 57 mg/m? H-24678 or greater. Threeof 6rats died at a `concentration of 57 mg/m? and all rats died at 120 mg/m. Rats died within 1 day of exposure. Clinical signsof toxicity noted during the study included a diminished response to an auditory. stimulus in rats during exposure to 57 or 120 mg/m. In addition, rats exposed at 120 mg/m? exhibited lethargy, lung noise, and labored breathing immediately following the exposure. One rat exposed at 23 mg/m? exhibited slight body-weight loss within 1 day of exposure (2.1% of pre-exposure body weight) but began to regain weight by test day 2. Ras exposed at 57 mg/m? exhibited slight to moderate body-weight losses within 2 daysofexposure (3.1 to 14% of pre-exposure body weight) but began to regain weight by test day 3.
C. Anatomic Pathology Evaluation (Appendix A)
1. Gross Pathology
There were no gross pathologic observations in any of the tissues examined.
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2. Microscopic Pathology
`There were no microscopic pathologic observations in any of the tissues examined.
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24678: nhation Approximate Lethal Concenration (ALC) in Rats
Dupont8684
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CONCLUSIONS
Under the conditions of this study, the approximate lethal concentration (ALC) for H-24678 is. 57 mg/m. According to Haskell Laboratory toxicity classifications, H-24678 is considered to be
extremely toxic (ALC less than 0.08 mg/L) in male rats.
RECORDS AND SAMPLE STORAGE
Specimens(ifapplicable), raw data, and the final report will be retained at Haskell Laboratory, Newark, Delaware, or at Iron Mountain Records Management, Wilmington, Delaware
REFERENCES 1. CSearliccusla2t1i0onAdmebsicernibteCdaisncSaideerrIamIpnascttrourmsenatnsd, CIyncc.l,oBnuellPerteisncp7a-r7a9t-o2rs1.9IM, Instruction Manual.
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H-24676: Inhalation Approximate Lethal Concentration (ALC) in Rats
DuPont8684
TABLE |
CHARACTERIZATION OF TEST ATMOSPHERES AND ASSOCIATED ANIMAL MORTALITY
"AEROSOL CONCENTRATION
(mg/m)*
AEROSOL SIZE MORTALITY
MMAD
Percent| (# deaths/
Mean SD. Range n| (um GSD <10pum'| #exposed)
23
37 14-27 8| 14 19-100
0/6
57
13 2.77 8 18 20 -100
3/6
120 1110-140 8] 13 19-100
6/6
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H-24678: Inhalation Approximate Lethal Concentration (ALinCRa)ts
DuPont 8684
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APPENDIX A
Individual Animal Pathology Data
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Individual Animal Pathology Date
Concentration: 57 mg/m Sex: wales
Animal Ref
Microscopic & Macroscopic Findings
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Gross Pathology
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Histopathology
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Gross rathology
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Histopathology
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Gross pathology :
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Histopathology
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