potassium (oxido-NNO-azoxy)cyclohexane; cyclohexylhydroxydiazene 1-oxide, potassium salt; [K-HDO]

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1971

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1971

Report date:

1971

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

Before OECD guideline 404 was established, eye initiation was tested using an internal method (BASF test). However the method is comparable to OECD 405.

Principles of method if other than guideline:

- Principle of test: in vivo skin irritation / corrosion test
- Short description of test conditions: The skin of the back of the rabbit was exposed for 1, 5 and 15 minutes and 20 hours to a test patch (about 2.5 x 2.5 cm) impregnated with the test substance (patch test). Following the short exposure (time test), the treated areas of skin were first washed with undiluted Lutrol 9 and then with a 50 % strength aqueous solution of Lutrol, while the skin was untreated after exposure for 20 hours. On the rabbit ear, cotton carriers impregnated with 1-2 ml of test substance were fixed inside the external ear with gauze dressings for 20 hours. In each case, the findings were recorded on removal of the dressing and after 1, 3 and 8 days.
- Parameters analysed / observed: local irritant effect, signs of toxicity due to absorption

GLP compliance:

no

Remarks:

GLP was not compulsory at the time the study was performed

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexylhydroxydiazene 1-oxide, potassium salt

EC Number:

613-953-8

Cas Number:

66603-10-9

Molecular formula:

C6H11KN2O2

IUPAC Name:

Cyclohexylhydroxydiazene 1-oxide, potassium salt

Test material form:

liquid

Details on test material:

Xyligen 30F is a 30% aqueous solution of K-HDO.

Test animals

Species:

rabbit

Strain:

Vienna White

Details on test animals or test system and environmental conditions:

- Source: obtained commercially
- Sex: male / female
- Weight at study initiation: 2.75 kg (mean value)
- Diet: ad libitum
- Water: ad libitum

Test system

Type of coverage:

not specified

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

The product was applied undiluted to the skin of the back and ears of the rabbit.

Duration of treatment / exposure:

1, 5 and 15 minutes and 20 hours

Observation period:

8 days

Number of animals:

3 male / 1 female animal

Details on study design:

TEST SITE
- Area of exposure: 2.5 x 2.5 cm

REMOVAL OF TEST SUBSTANCE
- Washing (if done): First washed with undiluted Lutrol 9 and then with a 50 % strength aqueous solution of Lutrol
- Time after start of exposure: Dorsal skin: 1, 5, 15 min and 20 hours; rabbit ear: 20 hours

OBSERVATION TIME POINTS
(indicate if minutes, hours or days): 24 hours and 8 days

SCORING SYSTEM:
- BASF scoring system:
Explanation of signs:
0 = non-irritant
+ = slight
++ = severe
R = reddening
S = scaling

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: erythema and eschar formation on the back of the test animal

Basis:

mean

Time point:

24 h

Score:

4

Reversibility:

not reversible

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

24 h

Score:

2

Reversibility:

fully reversible

Results 3

Irritation parameter:

erythema score

Basis:

mean

Time point:

24 h

Score:

2

Reversibility:

fully reversible

Irritant / corrosive response data:

The undiluted product was non-irritant on exposure of the very sensitive dorsal skin for short periods (1, 5 and 15 minutes). On exposure for 20 hours, Xyligen 30 F led to moderately severe overlapping reddening, which was spotty in some cases, and to slight swelling; there was formation of coarse scars after 8 days. Only a slight reddening, which disappeared within 8 days, was observed in the 20-hour test on the skin of the ear.

Other effects:

No signs of toxicity due to absorption were observed.

Any other information on results incl. tables

The conditions of 20h exposure without washing after exposure are more severe compared to the conditions recommended by the OECD guideline (4h exposure, washing after exposure). However, without a more adequate test the reported results have to be used for hazard assessment as worst case situation. The average score for 24h, 48h and 72h cannot be calculated, since no results are documented for 48h and 72h. Therefore, the 24h score has to be used instead.

Applicant's summary and conclusion

Conclusions:

After translation to OECD scores the 24h average scores are: For the back for erythema and eschar formation 4 and not reversible and for edema 2 (reversible); for the ear the erythema formation score is 2 (reversible). Therefore 30% K-HDO is considered to be irritating to skin.

Executive summary:

The primary irritant effect of Xyligen 30F on rabbit skin and mucosa has been tested. The undiluted product was non-irritant on exposure of the very sensitive dorsal skin for short periods (1, 5 and 15 minutes). On exposure for 20 hours, Xyligen 30F led to moderately severe overlapping reddening, which was spotty in some cases, and to slight swelling; there was formation of coarse scales after 8 days. Only a slight reddening, which disappeared within 8 days, was observed in the 20-hour test on the skin of the ear.