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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
February 22 - March 24, 2006
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study followed OECD guideline 425 and was conducted under GLP assurances

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
2006

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)
Deviations:
no
GLP compliance:
yes
Test type:
up-and-down procedure
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
The test substance, identified as 2,2,4,4-Tetramethyl-1,3-cyclobutanediol, Lot #X29601-54-5, was received on December 19, 2005 and was further identified with PSL Reference Number 051219-3H. The test substance consisted of white crystals and was stored at room temperature. Prior to use,
the test substance was ground in a coffee mill. Test article purity was 99.6%.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals and environmental conditions:
Test Animals
Sex: Female, nulliparous and non-pregnant.
Species/Strain: Rat, Sprague-Dawley derived, albino.
Age/Body weight: Young adult (10-11 weeks)/186-230 grams at experimental start.
Source: Received from Ace Animals, Inc., Boyertown, PA

Housing: The animals were singly housed in suspended stainless steel caging with mesh floors. Litter paper was placed beneath the cage and was
changed at least three times per week.
Animal Room Temperature Range: 19-24°C
Photoperiod: 12-hour light/dark cycle
Acclimation Period: 15-24 days
Food: Purina Rodent Chow #5012
Water: Filtered tap water was supplied ad-libitum by an automatic water dispensing system.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
The test substance was ground then administered as a 40% w/w mixture in com oil using a stainless steel ball-tipped gavage needle attached to an
appropriate syringe. Due to the high volume of test mixture to be administered for the 5,000 mg/kg dose level (12.63 ml/kg), each animal's dose was divided into two approximately equal portions, administered two hours apart. Prior to each dosing, experimentally naive rats were fasted overnight by removing the feed from their cages.Feed was replaced approximately 3-4 hours after the final dosing.
Doses:
470, 1,500, 5,000 mg/kg
No. of animals per sex per dose:
470: 2/sex
1,500: 4/sex
5,000: 3/sex
Control animals:
no
Details on study design:
All animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for up to 14 days after dosing. Body
weights were recorded prior to administration and again on Days 7 and 14 (termination) following dosing or after death. Necropsies were performedon all animals.
Statistics:
The Acute Oral Toxicity (Guideline 425) Statistical Program (Weststat, version 1.0, May 2001) was used for all data analyses including: dose progression selections, stopping criteria determinations and/or LD50 and eonfidence limit calculations.

Results and discussion

Effect levels
Sex:
female
Dose descriptor:
LD50
Effect level:
ca. 1 500 mg/kg bw
Mortality:
470: 0/2
1,500: 1/4
5,000: 3/3; All died within five hours of the test substance administration
Clinical signs:
470: There were no adverse pharmacologic effects, or abnormal behavior.
1,500: One female died within six hours of the test substance administration. Prior to death, this animal was hypoactive. Following administration, all survivors were hypoactive and one female exhibited piloerection. However, the survivors recovered by Day l and appeared active and healthy for the
remainder of the study.
5,000: Prior to death, animals were hypoactive and one exhibited hunched posture and piloerection.
Body weight:
470: Both animals gained body weight and appeared active and healthy during the study.
1,500: Survivors recovered by Day l and appeared active and healthy for the remainder of the study, gaining body weight over the entire 14-day
observation period.
5,000: All died
Gross pathology:
470: No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.
1,500: Gross necropsy of the decedent revealed a red discoloration of the intestines. No gross abnormalities were noted for any of the euthanized
animals when necropsied at the conclusion of the 14-day observation period.
5,000: Gross necropsy of the decedents revealed a red discoloration of the intestines.

Applicant's summary and conclusion

Conclusions:
Under the conditions of this study, the acute oral LD50 of 2,2,4,4-tetramethyl-1,3-cyclobutanediol is estimated to be 1,500 mg/kg of body weight in female rats with a 95% confidence interval of I ,043 mg/kg (lower) to 4,350 mg/kg (upper).
Executive summary:

An acute oral toxicity test (Up and Down Procedure) was conducted with rats to determine the potential for

2,2,4,4 -tetramethyl-1 ,3 -cyclobutanediol to produce toxicity from a single dose via the oral route. Under the conditions of this study, the acute oral LD50 of the test substance is estimated to be 1,500 milligrams per kilogram of body weight in female rats with a 95% confidence interval of 1,043 mg/kg (lower) to 4,350 mg/kg (upper). Based on the estimated LD50 of the test substance supplied by the sponsor (1,500 mg/kg), a Main Test was conducted using a default starting dose level of 470 mg/kg, which was administered to one healthy female rat by oral gavage. Following the Up and Down procedure, eight additional animals were dosed at levels of 470, 1,500, or 5,000 mg/kg. Females were selected for the test because they are frequently more sensitive to the toxicity of test compounds than males. All animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once

daily for up to 14 days after dosing. Body weights were recorded prior to administration and again on Days 7 and 14 (termination) following dosing or after death. Necropsies were performed on all animals. All low dose animals were healthy and active with no evidence of toxicity. Animals dosed with 1,500 mg/kg showed hypoactivity with one of four dying. No gross abnormalities were noted accept for red intestines in the one dead animal. All animals died at the 5,000 mg/kg dose showing clinical signs of hypoactivity with one exhibiting a hunched posture and piloerection, and all exhibited red colored intestines.