2,2'-methylenebis(6-nonyl-p-cresol)

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 March 1957 - 27 December 1957

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study pre-dates GLP and the standard guidelines; nevertheless, data is well reported and the experiment is conducted in accordance with generally accepted scientific principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1957

Report date:

1957

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-methylenebis(6-nonyl-p-cresol)

EC Number:

232-092-5

EC Name:

2,2'-methylenebis(6-nonyl-p-cresol)

Cas Number:

7786-17-6

Molecular formula:

C33H52O2

IUPAC Name:

2-[(2-hydroxy-5-methyl-3-nonylphenyl)methyl]-4-methyl-6-nonylphenol

Test material form:

liquid: viscous

Test animals

Species:

rat

Strain:

other: Albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: young adult.
- Weight at study initiation: 175 - 225 g.
- Fasting period before study: 18 ± 2 hours.
- Housing: Individually caged after dosing.
- Diet: ad libitum.
- Water: ad libitum.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

cotton seed oil

Details on oral exposure:

Dosed as a 50 percent solution in cottonseed oil.

Doses:

16.38, 22.62 and 32.72 g/kg bw

No. of animals per sex per dose:

10 animals per sex per dose level.

Control animals:

no

Details on study design:

PROCEDURE
Following the fasting period, the animals were divided into pairs and dosed with the appropriate amount of test material. The highest dose represents the maximum feasible dose for intra-gastric administration.

After dosing, the animals were observed daily for appearance and behaviour. Bodyweight and mortality records were made over a 14 day period.

Rats that died, as well as survivors sacrificed at the end of the experiment, were examined for evidence of gross pathology.

Statistics:

The LD50 was computed according to the method of Miller and Tainter (1944).

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 32.7 other: g/kg bw

Based on:

test mat.

Mortality:

Mortality did not increase in proportion to the dosage.
- 4 deaths (20 %) occurred in the 16.38 g/kg dose group.
- 5 deaths (25 %) occurred in the 22.62 g/kg dose group.
- 3 deaths (15 %) occurred in the 32.72 g/kg dose group.

Clinical signs:

other: All rats showed evidence of abdominal pain, excessive laxation and urinary incontinence.

Gross pathology:

No gross evidence of pathology was seen at necropsy among the survivors sacrificed after 14 days. In the examination of those that died throughout the observation period, the gastric mucosa was observed to be hyperaemic.

Any other information on results incl. tables

Table 1 Summary of Results

Dose (g/kg)	No. of Rats	Average Bodyweight* (g)		Symptoms (No. of rats exhibiting symptom)				Number of Deaths				Mortality (%)
		Days						Days
		0	14	A	E	U	P	1	2	3	Over 3
16.38	20	199.0 (198.5)	230.5	20	20	20	2	0	2†	0	2	20
22.62	20	203.0 (203.4)	236.4	20	20	20	5	0	3	0	2	25
32.72	20	197.0 (198.8)	234.3	20	20	20	3	0	0	1	2	15

*Parenthetical figures show the average initial weights of the survivors.

†This value was not legible in the original study report. However the value was easily inferred from the percentage mortality figure.

A = abdominal pain

E = excessive laxation

U = urinary incontinence

P = prostration

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study, the LD50 value was greater than 32.7 g/kg bw. The test material is not classified in accordance with EU criteria.

Executive summary:

An acute oral study was carried out to access the toxic potential of the test material, broadly in accordance with OECD guideline 401.

The test material was administered as a 50 percent solution in cottonseed oil to groups of young adult albino rats at dose levels of 16.38, 22.62 and 32.72 g/kg bw (with ten animals per sex per dose). The animals were observed for 14 days before being subjected to necropsy.

Whilst some mortality was seen, it did not increase in proportion to the dosage. Clinical signs exhibited by all animals were abdominal pain, excessive laxation and urinary incontinence.

No gross evidence of pathology was seen at necropsy among the survivors sacrificed after 14 days. In the examination of those that died throughout the observation period, the gastric mucosa was observed to be hyperaemic.

Under the conditions of this study, the LD50 value was greater than 32.7 g/kg bw. The test material is not classified in accordance with EU criteria.