Ethanol, 2-methoxy-, manufacture of, by-products from, esters with boric acid

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

1992-08-18 to 1993-02-02

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study is well documented and performed according to Charnoff and Kavlock screening method. In combination with the 28-day toxicity study (Shell, 1993), first indications on reproductive toxicity are avaialable.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Charnoff and Kavlock protocol

Deviations:

not applicable

Remarks:

10 dams per group - dosing GD 7-17, pups followed to post partum day 5 of lactation.

Principles of method if other than guideline:

Charnoff, N. and Kavlock, R.J. (1981). A potential in vivo screen for the determination of teratogenic effects in mamals. Teratology, 21, 34A.
The method uses smaller numbers of litters, and no skeletal or visceral examination, but follow pups post-partum to day 5 of lation at which time dams and pups are necropsied for gross pathological lesions.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Brake Fluid DOT 4 (lot 4200) containing B-TTEGME

IUPAC Name:

Brake Fluid DOT 4 (lot 4200) containing B-TTEGME

Details on test material:

- Name of test material (as cited in study report): Brake fluid 500 Dot 4
- Substance type: Borated Glycol Ether
- Physical state: Clear colourless liquid
- Analytical purity: 17% B-TEGME; Confidential details on test material
- Impurities (identity and concentrations): Confidential details on test material
- Composition of test material, percentage of components: Confidential details on test material
- Isomers composition: Not applicable
- Purity test date: Not provided
- Lot/batch No.:4200 (SNC sample No.); Indent 9450/9486; toxicology Ref. No. ST91/267
- Expiration date of the lot/batch: Not provided
- Stability under test conditions: Room temperature

Test animals

Species:

rat

Strain:

other: Crl:CD(SD)BR

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Manston, UK
- Age at study initiation: 8-9 weeks
- Weight at study initiation: No data
- Housing: polypropylene cages (pattern RB3R); single housing from day 7-17 of pregnancy and with pups during lactation
- Diet: certified pelleted diet (Expanded, Special Diets Services), ad libitum: initially LAD1; later LAD2
- Water: public supply, ad libitum
- Acclimation period: at least 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23
- Humidity (%): 45-70 (at one occasion, it rose up to 74%).
- Air changes (per hr): Air conditioning
- Photoperiod (hrs dark / hrs light): 12/12
- No indications of bacterial contamination (each week a blood agar plate was exposed to air for one hour)

IN-LIFE DATES: From: 1992-08-18 To: 1992-09-27

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

Once daily via oral gavage, sham dosed controls

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

The test article was dosed as supplied, without formulation. The test article was analytically verified prior to start of the study.

Details on mating procedure:

- Impregnation procedure:
- M/F ratio per cage: 1 male with 2 females were co-housed
- Length of cohabitation: 3 days
- After 3 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: No data
- Verification of same strain and source of both sexes: No data
- Proof of pregnancy: vaginal plug referred to as day 1 of pregnancy
- Any other deviations from standard protocol: no

Duration of treatment / exposure:

Gestation day 7-17

Frequency of treatment:

Once daily

Duration of test:

Study was terminated on lactation day 5.

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0 - 25 - 150 - 1000 mg/kg bw/day
Basis:
other: brake fluid - oral gavage

Doses / concentrations 2

Remarks:

Doses / Concentrations:
0- 9.5 - 57 - 380 mg/kg bw/day
Basis:
other: B-TTEGME

No. of animals per sex per dose:

10 pregnant dams/dose

Control animals:

yes, sham-exposed

Details on study design:

A positive control group consisting of 10 dams treated with ethylene glycol diethyl ether (EGDE) at 1000 mg/kg/day was included in the study.

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least twice daily on weekdays and once daily at week-ends or public holidays.
- Cage side observations: clinical alterations to skin, eyes, fur and visible mucous membranes, for abnormal patterns of behavior, disturbances of major body systems (e.g. respiratory, alimentary, urinary and nervous systems) and for gross deviation in food and water consumption.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Preganacy: vaginal plugs. Parturition: as soon as possible after parturition the number of live pups born and the number found dead in each litter were recorded. Particular attention was paid to impaired maternal care by the dams (e.g. inadequate construction and cleaning of the nest, pups left scattered and cold).

BODY WEIGHT: Yes
- Time schedule for examinations: days 1, 7 and 21 of gestation and again on day 5 on lactation.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes (GD 1-7, GD 7-17, GD 17 – LD1, LD 1-5)
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

POT-MORTEM EXAMINATIONS: Yes /
- Sacrifice on gestation day 5 of lactation or day 25 of gestation
- Organs examined: uterus (number of implantation sites)

OTHTER: no

Ovaries and uterine content:

The uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No (not applicable)
- Number of corpora lutea: No
- Number of implantations: Yes
- Number of early resorptions: yes
- Number of late resorptions: Yes
- Other: No

Fetal examinations:

- External examinations: Yes: visible external abnormalities (all per litter)
- Time schedule: at least twice daily on weekdays and once daily at week-ends or public holidays.
- Soft tissue examinations: No
- Skeletal examinations: No
- Head examinations: No
- Gross pathology: presence or absence of milk in the stomach

Statistics:

No statistical analysis was performed. Group mean comparisons were deemed sufficent ot form critical conclusions.

Indices:

Birth index, Live birth index and Viability index were calculated.

Historical control data:

Not provided

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
No effects on clinical signs, food or water inatke were observed with Brake fluid 500 Dot 4.
Dam treated with the positive control exhibited enlarged livers and spleens.

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

2

Dose descriptor:

NOAEL

Effect level:

>= 380 mg/kg bw/day (actual dose received)

Based on:

act. ingr.

Basis for effect level:

other: developmental toxicity

3

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

4

Dose descriptor:

NOAEL

Effect level:

>= 380 mg/kg bw/day (actual dose received)

Based on:

act. ingr.

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
No treatment-related effects on post-implantation loss were seen.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Table 2. Maternal findings

parameter	Control	Positive control 1000 mg/kg EGDE	25 mg/kg brake fluid	150 mg/kg   brake fluid	1000 mg/kg   brake fluid
No. pregnant	10	9	10	10	9
Duration of pregnancy - 21 days - 22 days - 23 days Mean duration (days)	3 7 0 22	- - - -	3 7 0 22	3 7 0 22	0 7 2 22
Mean Body weight (g) - day 1 - day 7 - day 21	249 289 430	254 295 322	246 290 424	247 291 437	249 289 430
Mean Food intake (g/animal/day) - GD 1-7 - GD 7-17 - GD17 – LD1 - LD1 – LD5	25 29 31 34	25 22 24 *	27 29 29 28	25 30 29 35	25 28 29 38

* No animals littered, killed day 25 of gestation

 

Table 3. Foetal findings

parameter	Control	Positive control 1000 mg/kg EGDE	25 mg/kg	150 mg/kg	1000 mg/kg
Mean implantation sites	16	16	15	18	16
Mean No. of life pups - LD 1 - LD 5	15 15	- -	13 12	17 16	15 14
Mean birth index Mean live birth index Mean viability index	95 98 98	0 - -	85 100 96	94 99 94	95 99 98
Group mean litter weight (g) - LD 1 - LD 5	90 133	- -	79 109	101 138	97 150

GD: gestation day  LD: lactation day

Applicant's summary and conclusion

Conclusions:

Brake Fluid containing 38% B-TTEGME did not show any reproductive or developmental toxicity up to the maximal dose of 1000 mg/kg bw/day in the Charnoff Kavlock reproductive/developmental screening study in rats.

Executive summary:

Brake Fluid DOT 4 is considered to have a similar toxicological profile as B-TTEGME. Brake fluid containing 38% B-TTEGME (of wich 17% B-TEGME) was administered to groups of 10 mated female CD-1 rats from gestation days 7 -17 at doses of 0, 25, 150, or 1000 mg brake fluid/kg bw/day, corresponding with  0, 9.5, 57 and 380 mg B-TTEGME/kg bw/day.  Dams were allowed to litter and the pups observed and weighed on days 1 and 5 post-partum, at which point the study was terminated. No treatment related effects on birth, live birth, or viability indices were found. No treatment-related clinical effects were seen on dams or pups, and there were no gross abnormalities seen in the pups. The NOAEL for this study was at least 1000 mg brake fluid /kg bw/day for systemic, reproductive, and developmental toxicity, corresponding with 380 mg B-TTEGME/kg bw/day.