Nitroethane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 Nov 1979 - 31 Dec 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

An intradermal sensitization test was conducted by injecting nitroethane solution (P-1355) into male guinea pigs according to Landsteiner and Jacobs procedure (Landsteiner, K., and J. Jacobs. "Studies on Sensitization of Animals with Simple Chemical Compounds. J. Exp. Med. 61:643-656, 1935).

GLP compliance:

no

Type of study:

other: Landsteiner and Jacobs

Justification for non-LLNA method:

This study was conducted before the LLNA method became available,

Test material

Test material information

Constituent 1

Reference substance name:

Nitroethane

EC Number:

201-188-9

EC Name:

Nitroethane

Cas Number:

79-24-3

Molecular formula:

C2H5NO2

IUPAC Name:

nitroethane

Details on test material:

The test material consisted of 97.70% nitroethane, 0.13% nitromethane, 1.80% 2-nitropropane and 0.024% water.

In vivo test system

Test animals

Species:

guinea pig

Strain:

not specified

Sex:

male

Details on test animals and environmental conditions:

Thirty male guinea pigs weighing 250 to 300 g were divided into three groups of 10 each. The animals' backs and flanks were shaved free of hair.

Results and discussion

Positive control results:

In the positive control (Group II) at 24 h, eight animals with 0.03% and ten animals with 0.3% solution of DNCB showed skin reactions. At 48 hours all the animals challenged with 0.3% DNCB solution showed skin reactions.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

1% test substance

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1% test substance

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 3

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.3% DNCB

No. with + reactions:

10

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Results 4

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

0.3% DNCB

No. with + reactions:

10

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Results 5

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0.9% saline, challenge with 1% of test substance

No. with + reactions:

2

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Results 6

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0.9% saline, challenge with 1% of test substance

No. with + reactions:

1

Total no. in group:

10

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

During the induction phase the guinea pigs in Group I showed some skin reactions when injected with 10% (first two injections) and 5% (third injection) solution, so the last seven injections were made with a 1% solution of P-1355. None of the animals in Group III showed any skin reactions. The animals in Group II showed mild to necrotic skin reactions during the entire induction period. At challenge, Group I (treatment group) and Group III (negative control) guinea pigs were intradermally injected with 1.0% solution of P-1355, and none of the animals in Group I showed any skin reactions, but two animals at 24 h and one animal at 48 h in Group III showed mild reactions.

Table 1 P-1355 Intradermal Sensitization Challenge Skin Reactions Scores in Guinea Pigs

Description	Group I Test Material		Group II Positive Control				Group III Negative Control
Material injected	P-1355		DNCB				Saline
Number of animals	10		10				10
Induction dose % conc.	10 to 1		0.3				0.9
Challenge material	P-1355		DNCB				P-135		DNCB
% Conc./site	1		0.3		0.03		1		0.3		0.03
Reaction scored at (h)	24	48	24	48	24	48	24	48	24	48	24	48
No. reacted/No. challenged	0/10	0/10	10/10	10/10	8/10	10/10	2/10	1/10	0/10	0/10	0/10	0/10

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Nitroethane (P-1355) was a non-sensitiser to the guinea pigs under the conditions of this test. The positive control DNCB gave an expected positive response.

Executive summary:

The dermal sensitization potential of nitroethane was examined using the method of Landsteiner and Jacobs. Nitroethane (P-1355) was a non-sensitiser to the guinea pigs under the conditions of this test. The positive control DNCB gave an expected positive response.