Piperazine

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 November - 31 December 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Evaluation of skin sensitization and cross-reaction of 9 alkylene amines

Author:

Leung HW, Auletta CS

Year:

1997

Bibliographic source:

J Toxicol Cut & Ocular Tox 16:189-195

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Principles of method if other than guideline:

Magnusson Kligman Assay

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The original Test Guideline for the determination of skin sensitization in the mouse, the Local Lymph Node Assay (LLNA; TG 429) was adopted in 2002, and this study was carried out in 1989 and published in 1997.

Test material

Test material information

Constituent 1

Reference substance name:

Piperazine

EC Number:

203-808-3

EC Name:

Piperazine

Cas Number:

110-85-0

Molecular formula:

C4H10N2

IUPAC Name:

piperazine

Specific details on test material used for the study:

White solid; clear liquid when melted
Date of receipt: September 19, 1989
From: Union Carbide Corporation
Storage: Room temperature
Vehicle: distilled water

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

Housing individually in suspended stainless steel cages.
Temperature monitored and recorded twice daily.
Humidity monitored and recorded daily.
Light Cycle: 12 hours light, 12 hours
Feed and water ad libitum
Concentrations based on prelimiinary testing.
dark (controlled by an automatic
timer).

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

Intradermal induction 5%, Epicutaneous induction 50%

Challenge

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Epicutaneous challenge 25%

No. of animals per dose:

10 male and 10 female

Details on study design:

Groups of 10 male and 10 female guinea pigs each received 0.1 ml intradermal induction injections into 2 sites each of the clipped shoulder skin as follows: 50% (v/v) Freund's complete adjuvant (FCA) water emulsion, the test material or vehicle, and the test material in FCA/water emulsion or FCA/water emulsion. Epicutaneous inductions were conducted 7 days later. The test material was applied to a 2 x 4 cm filter paper, which was then placed on the test site and secured with tape. The patches were left in place for 48 h, after which they were removed and the skin wiped free of any excess test material. Epicutaneous challenge was undertaken by applying 2 x 2 cm filter paper squares soaked in the ethylenediamine solution to a previously untreated site (right flank) 14 days after epicutaneous induction (i.e., 21 days from the start of the study). Patches were left in place for 24 h, and the sites inspected for signs of irritation 24-48 h after removal of the occlusive dressings.
Seven days later (day 28) the animals were rechallenged. Dermal responses were scored 24 and 48 h after each challenge.

Challenge controls:

Irritation control animals, five male and five female guinea pigs, received the same challenge procedures as in the definitive sensitization study, but did not have preceding intradermal and/or epicutaneous induction procedures

Positive control substance(s):

no

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

19

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

1

Total no. in group:

19

Results 3

Reading:

rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

3

Total no. in group:

19

Results 4

Reading:

rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

1

Total no. in group:

19

Results 5

Reading:

other: challenge, rechallenge, all time points

Group:

negative control

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Results 6

Group:

positive control

Remarks on result:

not measured/tested

Any other information on results incl. tables

One Piperazine-treated animal, a female, was found dead on Day l7 of the study. Gross postmortem observations revealed red fluid in the intestines and adhesions of the kidneys to the abdominal wall. The relationship of the death of this single animal to test material administration is considered questionable.

The majority of surviving animals gained weight during the study.

A summary of dermal responses is presented in Tables II and III (attached).

Redness or edema at the challenge site at any of the observations which is greater than that seen in the irritation control animals is considered an allergic response. In general, dermal scores of l or greater (in the absence of dermal response in irritation control animals) are considered clearly indicative of sensitization. Scores of 0.5 (barely perceptible erythema) are considered equivocal, although a high percentage of scores of 0.5 in treated animals with no dermal response in irritation control animals is considered suggestive of sensitization. Number (percentages) of animals reacting, rather than intensity of reactions, is the criterion for categorizing materials as sensitizers and assessing sensitization potency. Only one of the nineteen animals challenged with Piperazine (Group IA) exhibited clear dermal responses (scores of l or higher) 24 and 48 hours after challenge; three additional animals exhibited scores of 0.5 at one or both intervals. No dermal responses occurred in any of the ten irritation control animals (Group 1B).

Because of the questionable nature of this response, a second challenge was performed. Three of the nineteen animals exhibited clear responses; four additional animals had questionable responses. No response was seen in the ten control animals. Based on these responses in three of the nineteen animals (16%), Piperazine would be considered to be a mild sensitizer under the conditions of this study.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the responses in three of the nineteen animals (16%) following a second challenge, piperazine would be considered to be a mild sensitizer under the conditions of this study.

Executive summary:

In a Guinea Pig maximisation test according to Magnusson-Kligmann, groups of 10 male and 10 female guinea pigs received intradermal, of 0,1 ml 5% Piperazine solution and epicutaneous induction of 50 % solution, for 48 h. Epicutaneous challenge (25%) was undertaken after 14 days. 5 males and 5 females serving as a control received the same treatment as in challenge procedure. One animal (5%) showed signs of sensitization.

Because of the questionable nature of this response, a second challenge was performed. Three of the nineteen animals exhibited clear responses; four additional animals had questionable responses. No response was seen in the ten control animals. Based on these responses in three of the nineteen animals (16%), Piperazine would be considered to be a mild sensitizer under the conditions of this study.