Lysozyme, hydrochloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 28 to December 07, 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test conducted following internationally accepted testing guidelines and performed according to the GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Lysozyme, hydrochloride

EC Number:

232-954-0

EC Name:

Lysozyme, hydrochloride

Cas Number:

9066-59-5

Molecular formula:

C616H963N193O182S10 x HCl

IUPAC Name:

Lysozyme, hydrochloride

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Justification of Species: the rabbit is preferred by the various regulatory agencies for use in primary dermal irritation testing.
- Source: Ray Nichols Rabbitry; Lumberton, TX.
- Age at study initiation: approx. 2.5-3 months.
- Weight at study initiation: males 2.300-2.525 kg; females 2.250-2.675 kg.
- Housing: suspended, wire bottom, stainless steel; one per cage.
- Diet: PMI Feeds, Inc.TM Lab Rabbit Diet #5321, in measured amounts.
- Water: municipal water supply analyzed by TNRCC Water Utilities Division; available ad libitum from automatic water system.
- Quarantine period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 3 °C
- Humidity: 30-70 %
- Air changes: 10-12 air change per hour
- Photoperiod: 12 hours cycle dark/light

IN-LIFE DATES
Animlas born in September 09, 2001. They were received by the laboratory at November 28 and were treated with the test substance on December 04. The in-life portion of the study was termined on December 07, 2001.

No contaminants were expected to have been present in the feed or water which would have interfered with or affected the results of the study.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

other: corn oil

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 g of the test substance were moistened with 0.5 ml of com oil

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3 males and 3 females

Details on study design:

TEST SITE
- Area of exposure: 8 x 8 cm
- Type of wrap if used: the test substance was applied to each test site and covered with 4 ply, 2.5 x 2.5 cm surgical gauze patch. Each patch was secured in place with a strip of non-irritating adhesive tape. The entire trunk of each animai was loosely wrapped with a semi-permeable dressing (orthopedic stockinette) which was secured an both edges with strips of tape to retard evaporation of volatile substances and to prevent possible ingestion of the test substance.

REMOVAL OF TEST SUBSTANCE
- Washing: the test site was gently washed with room temperature tap water and a clean cloth to remove as much residual test substance as possible.
- Time after start of exposure: 4 hours.

SCORING SYSTEM
The test sites were observed for erythema and edema formation, and any other dermal defects or irritation at 1, 24, 48 and 72 hours after unwrap.
The scoring scale used to rate dermal irritation is reported below.
For each animal, all of the erythema and oedema scores throught 7 hours were added, and the sum was divided by 4 to obtain an individual irritation score. The primary irritation index was determined by calculating the mean of the irritation scores for all the animals and was used to obtain a rating for the test substance.
Evaluation of the skin reactions
Erythema Formation
No erythema: 0
Very slight erythema (barely perceptible): 1
Well defined erythema: 2
Moderate to severe erythema: 3
Severe erythema (beef redness) to slight eschar formation (injuries in depth): 4
Maximum possible: 4

Oedema Formation
No oedema: 0
Very slight oedema (barely perceptible): 1
Slight oedema (edges of area well defined by definite raising): 2
Moderate oedema (raised approximately 1 mm): 3
Severe oedema (raised more than 1 mm and extending beyond area of exposure): 4
Maximum possible: 4

Classification of the test substance
Primary irritation index
0.0: non-irritant
0.1 - 1.9: slightly irritant
2.0 - 5.0: moderately irritant
5.1 - 8.0: severe irritant

Dermal irritation toxicity categories (per proposed rule, FR Vol. 49, No 188)
Toxicity category I: corrosive
Toxicity category II: severe irritation at 72 hours
Toxicity category III: moderate irritation at 72 hours
Toxicity category IV: non-irritating, mild, or slight irritation at 72 hours

Results and discussion

In vivo

Irritant / corrosive response data:

Primary irritation index: 0.1; based on the 72 hours observations the toxicity category IV was assigned.
Very slight erythema was present in three animals only at the 1 hour observation.
Oedema was not detected at any throughout the study.
No other signs of irritation were observed during the study.

Any other information on results incl. tables

Reaction	Observation time	Animal number-Sex
		3590 -M	3592 -M	3594 -M	3591-F	3593-F	3595-F
Erythema	1-h	1	1	0	0	1	0
	24-h	0	0	0	0	0	0
	48-h	0	0	0	0	0	0
	72-h	0	0	0	0	0	0
	Mean 24, 48 and 72 hrs	0.0	0.0	0.0	0.0	0.0	0.0
Oedema	1-h	0	0	0	0	0	0
	24-h	0	0	0	0	0	0
	48-h	0	0	0	0	0	0
	72-h	0	0	0	0	0	0
	Mean 24, 48 and 72 hrs	0.0	0.0	0.0	0.0	0.0	0.0
Primary irritation scores		0.25	0.25	0.0	0.0	0.25	0.0

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information according to the CLP Regulation Criteria used for interpretation of results: EU

Conclusions:

Not irritating

Executive summary:

A primary dermal irritation study was conducted on six albino rabbits. There was one intact test site per animal. Each test site was treated with 0.5 g of test substance moistened with 0.5 ml of corn oil and covered with a semi-permeable dressing. The test substance was maintained in contact with the skin for 4 hours. Observations for dermal irritation and defects were made at 1, 24, 48 and 72 hours after removal of the dressings.

Very slight erythema was present in three animals only at the 1 hour observation; on the contrary, oedema was not detected at any throughout the study. No other signs of irritation were observed during the study.

The primary irritation index: was stated at 0.1 and, based on the 72 hours observations, the toxicity category IV was assigned.

Conclusion

Not irritating.

The scoring system criteria used to record the hardness of the skin reactions followed in the current test are the same as those reported into the OECD guideline (404), therefore it is possible to re-evaluate the results according to the CLP Regulation (EC 1272/2008), because the raw tables are included into the study report.

Mean values from gradings at 24, 48 and 72 hours after patch removal were lower than 2.3 in all animals for both erythema/eschar and oedema reactions, thus the test item is out of the classification criteria for skin irritation potential, according to the CLP Regulation (EC 1272/2008).