Hexadecyl 3,5-bis-tert-butyl-4-hydroxybenzoate

Toxicity to reproduction

Administrative data

Endpoint:

one-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 7, 1980 through September 12, 1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Insufficient documentation of experimental methods and examination procedures. In general, this study was performed according to the SOPs, which are in conformity with the FDA GLP Regulations. Deviations were limited, listed below, and are believed not to impact the reliability of the test result.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Breeding/Reproductive Study

Deviations:

yes

Remarks:

See Below

Principles of method if other than guideline:

a. The first amendment was made to comply with the Sponsor's request to collect blood from rats at various stages of the study and to perform analysis on the quantity of compound absorbed.

b. The second amendment does not apply to this phase of the study,

c. The third amendment was made to specify the final report date,

d. The fourth amendment was made to modifv the final report date, and

e. The fifth amendment was made to document that feed assays were performed by the Sponsor.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hexadecyl 3,5-bis-tert-butyl-4-hydroxybenzoate

EC Number:

267-342-2

EC Name:

Hexadecyl 3,5-bis-tert-butyl-4-hydroxybenzoate

Cas Number:

67845-93-6

Molecular formula:

C31H5403

IUPAC Name:

hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

UV-2908 is a candiilate light stabilizer of thermoplastics manufactured by American Cyanamid Company. PRL received the test substance in a satisfactory condition in three shipments, for studies on rats and dogs, as follows: a. 70.9 kilograms in two cardboard drums were received on 3-21-80; b. 10 Kilograms in a cardboard container were received on 4-25-80; c. 45 kilograms in a cardboard drum were received on 5-21-80. All three shipments were from Lot #PP80-2 with a stated purity of 97.9% + or - 0.22%. The compound is a white powder which is odorless. It has been stored in a locked cabinet.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington Mass.
- Age at study initiation: weanling (35 days old)
- Housing: The animals in both phases of the study were individually housed in wire mesh suspended cages, except during breeding and weaning, when the dams and their offspring were kept in plastic cages.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period:Quarantinen for 14 day upon arrival.

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 73 + or - 2
- Humidity (%): 45% to 70% except during weekly hosing of tile floor for cleaning.
- Air changes (per hr): 10 times

Administration / exposure

Route of administration:

oral: feed

Vehicle:

other: First 20 days of Phase I of the study: Certified Rodent Chow, No. 5002 from Purina Company, St. Louis, Missouri.; May 27, 1980 until the end of the study: Charles River R-M-H 3200 Certified Meal, manufactured by Agway of Syracuse, N.Y.

Details on exposure:

The diets were prepared weekly by mixing the appropriate amount of UV-2908 with the appropriate amount of the basic diet with a Patterson-Kelley
2 cubic feet V-shaped mixer. Fresh diets were prepared weekly bassed on the feed consumption data obtained two weeks before. Feed consumption for each animal was measured weekly during the quarantine and for the next ten weeks on test during Phase 1. Feed and water was provided ad libitum.

Details on mating procedure:

Beginning the first day of the 11th week on test the rats were pair-mated within their respective groups. The males were rotated to the next female up on the 6th and 12th day of mating, with the last male in each group mated with the first female of the same group. The male rats were removed on the 18th day of
breeding and euthanized soon thereafter and the testes saved in 10% buffered formalin, in case it became necessary to perform histopathological examination on the reproductive organs of any of these rats. The females were allowed to deliver their young.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

The dose levels were set in advance by the Sponsor. Mixing Analyses: These analyses were performed by the Sponsor. Results sent to the lab indicated that the test article was properly mixed in the feed.

Duration of treatment / exposure:

18 Weeks

Frequency of treatment:

Daily thoroughly mixed in the feed.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

5 000 ppm

Remarks:

The low dose group received daily, thoroughly mixed in the feed, 5000 parts of UV-2908 per million parts of feed PPM corresponding to 0.5%.

Doses / concentrations 2

Dose / conc.:

10 000 ppm

Remarks:

The mid-dose group received daily, thoroughly mixed in the feed, 10000 parts of UV-2908 per million parts of feed PPM corresponding to 1.0%.

Doses / concentrations 3

Dose / conc.:

50 000 ppm

Remarks:

The high-dose group received daily, thoroughly mixed in the feed, 50000 parts of UV-2908 per million parts of feed PPM corresponding to 5%.

No. of animals per sex per dose:

High Dose: 20 female and 20 male
Mid Dose: 20 female and 20 male
Low Dose: 20 female and 20 male
Control: 20 female and 20 male

Control animals:

yes, plain diet

Positive control:

The control group of animals received the basic ration of feed for the duration of the study.

Examinations

Parental animals: Observations and examinations:

All rats were inspected daily by the Animal Caretakers and/or by the study coordinators. Positive findings were documented as they occurred while negative findings were documented once a week. Any abnormal findings observed were immediately followed. Pertinent signs were called to the attention of the Study Director and all data were reviewed regularly by him.

Litter observations:

All rats were inspected daily by the Animal Caretakers and/or by the study coordinators. Positive findings were documented as they occurred while negative findings were documented once a week. Any abnormal findings observed were immediately followed. Pertinent signs were called to the attention of the Study Director and all data were reviewed regularly by him.

Postmortem examinations (parental animals):

The gonads were preserved in 10% buffered formalin in case it became necessary to perform histological examination of the reproductive organs of any of the rats.

Statistics:

The following determinations were statistically evaluated by PRL using the independent, two sided Students t-test at the 9S% confidence level:
a. Feed consumption data
b. Body weight data

Scheffe, H.: Analysis of Variance, Wiley &: Sons, New York, N.Y., 1959.

Snedecor, G.W. an. Cochran, W.G.: Statistical Analysis, 6th ed., Iowa State Univ. press, Ames, La, 1967.

Reproductive indices:

Fertility Index: No. of pregnancies - No. of matings; Viability Index: No. of live pups at 4 days - No. of liveborn pups; Lactation Index: No. of weaned pups - (No. of live pups at day 4 - No. of pups discarded at day 4); Gestation Index: No. of litters born alive - No. of females pregnant

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Histopathological findings: non-neoplastic:

not examined

Description (incidence and severity):

The gonads were preserved in 10% buffered formalin in case it became necessary to perform histological examination of the reproductive organs of any of the rats.

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

It is clear that the reproductive process was very successful and that the compound at all dose levels appeared to have no detrimental effect.

Effect levels (P0)

Dose descriptor:

NOEL

Effect level:

50 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: All indices (fertility, viability, lactation, and gestation) were very high, indicating that the reproductive process was successful and that the compound at all dose levels did not influence the reproduction process.

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Details on results (F1)

No abnormalities were observed during the course of breeding, hence, the authors made the conclusion that the compound did not influence reproduction/teratogenicity.

Effect levels (F1)

Dose descriptor:

NOEL

Generation:

F1

Effect level:

50 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No effects on reproduction were seen at the highest dose level

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

All indices fertility, viability, lactation, and gestation were very high, indicating that the reproductive process was successful and that the compound at all dose levels did not influence the reproduction process.

Executive summary:

Reproductive process was successful and the compound at all dose levels did not influence the reproduction process. GLP compliance was followed. Test substance doses used in the study were as follows: low dose group received daily, thoroughly mixed in the feed, 5000 parts of UV-2908 per million parts of feed PPM 0.5%; mid-dose group received daily, thoroughly mixed in the feed, 10000 parts of UV-2908 per million parts of feed PPM 1.0%; high-dose group received daily, thoroughly mixed in the feed, 50000 parts of UV-2908 per million parts of feed PPM 5%.