2,2'-bipyridyl

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1972

Report date:

1972

Reference 2

Reference Type:

other: method publication

Title:

A method for determining the dermal toxicity of pesticides

Author:

Noakes DN, Sanderson DM

Year:

1969

Bibliographic source:

Br J Ind Med. 1969, 26(1):59-64;

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The method according to Noakes and Sanderson was used (Noakes DN, Sanderson DM, Br J Ind Med. 1969, 26(1):59-64). Briefly, the test item was applied on a 6x8 cm area of the skin of albino rats (whose hair was previously clipped) and then occlusively covered by a double layer of plaster. Exposure time was 24 h after which the plaster was removed and the test item was washed away using water and detergent. Observation time was 7 days.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-bipyridyl

EC Number:

206-674-4

EC Name:

2,2'-bipyridyl

Cas Number:

366-18-7

Molecular formula:

C10H8N2

IUPAC Name:

2,2'-bipyridine

Details on test material:

- Name of test material (as cited in study report): 2,2'-bipyridyl
- Substance type: yellowish-fawn crystalline solid
- Physical state: solid

Test animals

Species:

rat

Strain:

other: Alderley Park SPF albino

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 170-240 g

Administration / exposure

Type of coverage:

occlusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: back
- Type of wrap if used: plaster, double-layered

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes with warm water and soap
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.625 - 5 g/kg bw
- Constant volume or concentration used: no data
- For solids, paste formed: yes

Duration of exposure:

24 h

Doses:

625, 1250, 2500, 5000 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days
- Other examinations performed: clinical signs, body weight

Statistics:

In the study report at hand, only a LD50 range was given.
The here reported LD50 was calculated as arithmetic mean between the 625 and the 1250 mg/kg bw dose group.

Results and discussion

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LD50

Effect level:

> 625 - < 1 250 mg/kg bw

Based on:

test mat.

Remarks on result:

other: data as given in the study report

Effect levels 2

Sex:

female

Dose descriptor:

LD0

Effect level:

625 mg/kg bw

Based on:

test mat.

Remarks on result:

other: data as given in the study report

Effect levels 3

Sex:

female

Dose descriptor:

LD100

Effect level:

1 250 mg/kg bw

Based on:

test mat.

Remarks on result:

other: data as given in the study report

Mortality:

At all but the lowest dose (625 mg/kg bw), animals died within 24-48 h (table 1).

Clinical signs:

other: Animals in the 625 mg/kg bw dose group were hunched with piloerection but showed no tremors. In all but the lowest dose group, animals showed marked tremors and excreted orange-colored urine. The site of application showed severe erythema after removal of

Any other information on results incl. tables

Table 1: Cumulative mortality amongst rats treated dermally with 2,2’-bipyridine:

Time after application [d]	Dose [mg/kg bw] and cumulative mortality
	625	1250	2500	5000
1	0/3	2/3	3/3	3/3
2	0/3	3/3	3/3	3/3
7	0/3	3/3	3/3	3/3

 

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

After dermal application of 2,2-bipyridine to rats under occlusive dressing, 0 rats died at a dose of 625 mg/kg bw (LD0) but all rats in the group died at 1250 mg/kg bw (LD100). The LD50 is therefore between 625 and 1250 mg/kg bw.

Executive summary:

Dermal toxicity of 2,2'-bipyridine to rats was assessed by applying the test item as aqueous paste to the clipped skin of female rats for 24 h under occlusive dressing. The test item was applied in concentrations of 625, 1250, 2500, and 5000 mg/kg bw to three animals per dose group. Subsequently, the dressing was removed, the application site was washed and the animals were observed for 7 d.

The study was neither performed according to a guideline nor under GLP. Also were no information on body weights/weight gain available.

In all but the lowest dose (625 mg/kg bw), all animals died within 48 h after application exhibiting orange-colored urine and marked tremor. None of the rats in the 625 mg/kg bw dose group died but hunched posture with piloerection and impaired weight gain was observed in these animals. In all rats, severe erythema were observed at the application site after removal of the dressing.

The LD50 was between 625 and 1250 mg/kg bw.