Urea, reaction products with formaldehyde

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-06-24 2008-07-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The GLP study was conducted according to an internationally accepted guideline. All study parameters are based on the specific guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Urea, reaction products with formaldehyde

EC Number:

271-898-1

EC Name:

Urea, reaction products with formaldehyde

Cas Number:

68611-64-3

Molecular formula:

not available

IUPAC Name:

Urea, reaction products with formaldehyde

Test material form:

other: liquid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Approximately 24 hours before application the fur on the dorsal area of the trunk was removed by close clipping (area 6 x 6 cm). Only animals with healthy intact skin were used. After clipping the fur the animals were weighed.

Test system

Type of coverage:

occlusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

4 hours

Observation period:

Rabbits were examined for signs of erythema and oedema at 1, 24, 48 and 72 hours after patch removal.

Number of animals:

3

Details on study design:

The test substance in the dose of 0.5 g was applied on intact skin and then it was covered by gauze patch, foil and cellulose cotton and held in place with non-irritating tape -Spotaplast. At the end of each exposure period the patch was removed and remaining sample was washed with water.

In initial test three patches were applied sequentially to one animal. The first patch was removed after three minutes. No serious skin reaction was observed, so the second patch was applied for one hour. The observations at this stage indicated that exposure can humanely be allowed to extend to four hours, so the third patch was applied for four hours. After removing the patch, a response was graded. Because no corrosive or irritant effect was observed after a 4-hour exposure, the response was verified in confirmatory test using two additional animals, cach with one patch for an exposure period of 4 hours.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

4

Reversibility:

no data

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72 hours

Score:

0

Max. score:

4

Reversibility:

no data

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

No skin irritation was caused by 4-hour exposure to Weikoform (Urea, reaction products with formaldehyde).

Executive summary:

The test substance, Weikoform (Urea, reaction products with formaldehyde), was tested in the study for acute dermal irritation/corrosion. Rabbits (New Zealand Albino breed) were used for the test. Fest was performed according to Method B.4 - Acute Toxicity: Dermal Irritation/Corrosion, Council Regulation (EC) No.440/2008, published in O.J. L 142, 2008. Three rabbits were exposed to 0.5 g of test substance, applied onto clipped skin for 4 hours using a semi-occlusive dressing. Skin reactions were evaluated after patch removal and observations were made at 1, 24,48 and 72 hours after exposure. At first the test substance was applied on the skin of one rabbit (test animal No. 7). Rabbit No. 7 was investigated 3 minutes, 1 hour and 4 hours after application of the test substance. No symptoms of irritation were observed on the skin. In confirmatory test, two others rabbits (rabbit No. 8 and No. 9) were used with 4-hour exposition period. No evidence of a corrosive effect or symptoms of irritation were observed on the skin. No skin irritation was caused by 4-hour exposure to Weikoform (Urea, reaction products with formaldehyde). No other signs of intoxication were observed.