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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
yes
Remarks:
For two days the temperature was below the range stated in the protocol
GLP compliance:
yes
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test Substance: primeneTM 81-R (Lot No.: 0050A400, TD No. 00-025)

Test animals

Species:
rat
Strain:
other: Crl:CD BR
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Chrales River-Kingston, Stone Ridge, New York
- Age at study initiation: 8 weeks (males); 10 weeks (females)
- Weight at study initiation: 234-274 g (males); 219-267 g (females)
- Fasting period before study: no data
- Housing: 1/cage in suspended stainless steel cages
- Diet (e.g. ad libitum): PMI certified rodent chow 5002 (C)
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-22 degrees C
- Humidity (%): 38-70%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hours light/ 12 hours dark


IN-LIFE DATES: From: October 31, 2000 To: November 21, 2000

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
nose only
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 240-L Plexiglas and stainless steel chamber
- Exposure chamber volume: 240-L
- Method of holding animals in test chamber: nose-only restraining tubes (15 cm length x 5 cm diameter PVC pipe). Each animal was restrained in the tube with a neoprene stopper in the rear and a plastic funnel in the front.
- Source and rate of air: conditioned laboratory air airflow rate approximately 100 to 118 L/min
- Method of conditioning air: not aplicable
- System of generating aerosols: An FMI G20 RHOCKC Micropump (Fluid Metering, Oyster Bay, NY) delivered the neat test material to the top of a glass 20 inch counter current vapor generator. The test material dripped onto a heat coil (set at 120 degrees F, 140 degrees F or 130 degrees F for the 91, 231 and 151 ppm exposures, respectively) contained inside the glass counter current vapor generator. As the test material vaporized, compressed air (11 psi) forced the vaporized test material up through a glass manifold (wrapped in heat tape which maintained a temperature of 43 to 61 degrees C). The glass manifold delivered the vaporized test material into the top of the exposure chamber. Vaproized test material was directed into the top of a 240-L Plexiglas and stainless steel chamber and mixed with the conditioned laboratory air drawn through a HEPA particle filter located on the chamber inlet. The exposure atmosphere was exhausted at the bottom of the exposure chamber and passed through a series of filters (coarse particulate, HEPA, charcoal filters and an aqueous scrubber) before being released at roof level of the building. Chamber airflow was monitored continuously by measuring the pressure drop across a critical orifice plate located in the chamber exhaust duct.
- Method of particle size determination: no data
- Treatment of exhaust air: exhausted at the bottom of the exposure chamber and passed through a series of filters (coarse particulate, HEPA, charcoal filters and an aqueous scrubber) before being released at roof level of the building.
- Temperature, humidity, pressure in air chamber: 24.6 to 25.7 degrees C, 33% humidity


TEST ATMOSPHERE
- Brief description of analytical method used: The test material vapor in the inhalation chamber was directly sampled using silicosteel tubing connected to a 6 port gas sampling valve on a Gas Chromatograph (GC). Two samples/hour were taken during each exposure period to insure adequate characterization of the atmosphere. The saturated vapor concentration of the test material was determined using the same sampling and analytical methodology used to measure the test material concentrations during the animal exposures. The saturated vapor concentration was measured at room temperature (19°C) and at a temperature similar to that measured in the test atmosphere during the inhalation exposures (24°C). The saturated vapor concentration of the test material at room
temperature was obtained by placing 20 ml of the test material into a Tedlar bag and equilibrating the bag overnight at room temperature. The saturated vapor concentration of the test material at 24°C was obtained by placing 20 ml of the test material into a Tedlar bag and placing the bag in an oven overnight. The Tedlar bags were directly sampled using silicosteel tubing connected to a 6 port gas sampling valve on a Gas Chromatograph (GC).
- Samples taken from breathing zone: yes


VEHICLE not applicable; no vehicle

TEST ATMOSPHERE (if not tabulated) Not applicable- vapor study
- Particle size distribution:
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.):


CLASS METHOD (if applicable) not applicable
Analytical verification of test atmosphere concentrations:
yes
Remarks:
GC
Duration of exposure:
4 h
Concentrations:
91, 151, 231 ppm
No. of animals per sex per dose:
30
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: All animals were observed for signs of intoxication during the exposure period and daily for 14 days following exposure. Body weights were recorded on days 0, 7, and 14 during the fourteen-day observation period.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight
Statistics:
The female LC50, 95% confidence limits and slope were calculated from the logarithm of the doses and the incidences of mortality using a SAS PROBIT procedure (SAS Institute Inc. SAS User's Guide: Statistics, Version 6 Edition, p 1324 - 1350. Cary, NC: SAS Institute Inc., 1990) based on the method of D.J. Finney (Probit Analysis, Thrid Edition, London: Cambridge Universtiy Press, 1971)

Results and discussion

Preliminary study:
Not applicable
Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LC50
Effect level:
>= 157 ppm
95% CL:
> 90 - < 249
Exp. duration:
4 h
Sex:
female
Dose descriptor:
LC50
Effect level:
157 ppm
95% CL:
> 90 - < 249
Exp. duration:
4 h
Sex:
male
Dose descriptor:
LC50
Effect level:
> 231 ppm
Exp. duration:
4 h
Mortality:
- Time of death: Males - 2 at 231 ppm during exposure period (day 0). Females - 1 at 151 ppm during exposure period (day 0); 1 at 151 ppm on day 1; 3 at 231 ppm during exposure period (day 0); 1 at 231 ppm on day 1.
- Number of deaths at each dose: (number of deaths/number treated)
Dose (ppm) 91 151 231
Males 0/5 0/5 2/5
Females 0/5 2/5 4/5
Clinical signs:
other: Numerous clinical signs of toxicity were noted in all exposure levels in both sexes beginning upon removal from the chamber and continuing through day 7. These clinical signs included: respiratory noise, labored breathing, gasping, abnormal gait, ataxia,
Body weight:
There was no effect on body weight in either sex at any exposure level when compared to historical control values.
Gross pathology:
Necropsy of the decedents revealed dark, mottled and/or reddened lungs, distended stomachs, and thymus reddened and/or having multiple red foci. Necropsy of the survivors revealed no gross changes.
Other findings:
- Potential target organs: lungs
- Other observations: SEX-SPECIFIC DIFFERENCES: Even though the results did not indicate a statistically significant sex-related difference in mortality across dose groups for males and females, the LC50 was calculated on the female mortality incidences at each dose since at least 50% mortality was not observed in males at the highest exposure level (231 ppm).

Applicant's summary and conclusion

Interpretation of results:
Category 2 based on GHS criteria
Executive summary:

The acute inhalation toxicity of the test material was assessed in Crl:CD®BR rats. Three groups of five male and five female rats received a single 4-hr noseonly inhalation exposure to the test material vapor concentrations of 91, 151 and 231 ppm equivalent to 0.69, 1.14, and 1.75 mg test material/L of air. The saturated vapor concentration of the test material was determined using the same sampling and analytical methodology used to measure vapor concentration during the inhalation exposures. Measurements were made at approximately room temperature and at a temperature similar to that of the test atmosphere during the animal exposures. Exposure-related mortality occurred in animals exposed to the test material at 151 ppm and above. No deaths occurred in the 91 ppm group or in males at 151 ppm. The total mortality incidences (no. deaths/no. treated) for males and females in this study were:

Dose (ppm) 91 151 231

Males 0/5 0/5 2/5

Females 0/5 2/5 4/5

The LC50 value was calculated from the female mortality incidence data. Numerous clinical signs of toxicity were noted in all exposure levels in both sexes beginning upon removal from the chamber and continuing through day 7. These clinical signs included: respiratory noise, labored breathing, gasping, abnormal gait, ataxia, tremors, passiveness, scant feces, arched back, prostration and/or yellow/brown stained anogenital area. There was no effect on body weight among survivors in either sex at any exposure level. Necropsy of the decedents revealed dark, mottled and/or reddened lungs, distended stomachs, and thymus reddened and/or having multiple red foci. Necropsy of the survivors revealed no gross changes. The acute inhalation LC50 for the test material in female rats was 157 ppm (1.19 mg/L) with 95% confidence limits of 90 to 249 ppm. The acute inhalation LC50 for the test material in male rats was greater than 231 ppm (1.75 mg/L). The saturated vapor concentration of the test material was 150 ppm at 19°C (room temperature) and 220 ppm at 24°C (similar to temperature of test atmospheres).