Glycine

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

β-alanine

EC Number:

203-536-5

EC Name:

β-alanine

Cas Number:

107-95-9

Molecular formula:

C3H7NO2

IUPAC Name:

beta-alanine

Test material form:

solid: crystalline

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Animals and Animal Husbandry
Two New Zealand White rabbits were supplied by Harlan Laboratories U.K. Ltd., Loughborough, UK. At the start of the study the animals weighed 2.09 or 2.16 kg and were twelve to twenty weeks old. After an acclimatisation period of at least five days each animal was given a number unique within the study which was written with a black indelible marker-pen on the inner surface of the ear and on the cage label.

The animals were individually housed in suspended cages. Free access to mains drinking water and food (2030 Teklad Global Rabbit diet supplied by Harlan Laboratories U.K. Ltd., Oxon, UK) was allowed throughout the study. The diet and drinking water were considered not to contain any contaminantof a level that might have affected the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 17 to 23°C and 30 to 70% respectively. Any occasional deviations from these targets were considered not to have affected the purpose or integrity of the study. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

other: test material was moistened with 0.5 mL of distilled water.

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied:
0.5 g

- Concentration:
Not applicable.

VEHICLE
- Amount(s) applied:
0.5 g of test material was moistened with 0.5 ml of distilled water.

- Concentration:
Not applicable.

- Lot/batch no.:
Not given in study report.

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

2

Details on study design:

Preparation of Test Material
For the purpose of the study the test material was used as supplied.
The absorption of the test material was not determined.

Measurement of pH
The pH of the test material (10% w/w aqueous preparation of the test material) was determined prior to commencement of the study and found to be as follows: Measurement immediately, after 10 minutes and after 20 minutes: 6.8, 6.1 and 6.4.

Procedure
On the day before the test each of a group of two rabbits was clipped free of fur from the dorsal/flank area using veterinary clippers. Only animals with a healthy intact epidermis by gross observation were selected for the study.
On the day of the test a suitable test site was selected on the back of each rabbit. At each test site a quantity of 0.5 g of the test material, moistened sufficiently with 0.5 ml of distilled water to achieve a dry paste, was introduced under a 2.5 cm x 2.5 cm cotton gauze patch. The patch was secured in position with a strip of surgical adhesive tape. To prevent the animals interfering with the patches, the trunk of each rabbit was wrapped in an elasticated corset and the animals were returned to their cages for the duration of the exposure period.
Four hours after application the corset and patches were removed from each animal and any residual test material removed by gentle swabbing with cotton wool soaked in distilled water.
Immediately following removal of the patches and approximately 1, 24, 48 and 72 hours later, the test sites were examined for evidence of primary irritation and scored according to the following scale:

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: mean over 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Irritant / corrosive response data:

The individual scores for erythema/eschar and oedema are given in remarks on results including tables and figures.
No evidence of skin irritation was noted during the study.

Any other information on results incl. tables

The individual scores for erythema/eschar and edema are given in the following table.

Individual Skin Reactions

Skin Reaction	Observation Time (following patch removal)	Individual Scores – Rabbit Number and Sex		Total
		Male #1	Male #2
Erythema/Eschar Formation	Immediately	0	0	(0 )
	1 Hour	0	0	( 0 )
	24 Hours	0	0	0
	48 Hours	0	0	( 0 )
	72 Hours	0	0	0
Oedema Formation	Immediately	0	0	( 0 )
	1 Hour	0	0	( 0 )
	24 Hours	0	0	0
	48 Hours	0	0	( 0 )
	72 Hours	0	0	0
Sum of 24 and 72-HourReadings(S)      :          0
Primary Irritation Index (S/4)                   :          0/4 = 0.0

Bodyweight

Individual bodyweights and bodyweight changes are given in Table 2.

Both animals showed expected gain in bodyweight during the study.

Table 2              Individual Bodyweights and Bodyweight Changes

Rabbit Number and Sex	Individual Bodyweight (kg)		Bodyweight Change (kg)
	Day 0	Day 3
Male #1	2.16	2.22	0.06
Male #2	2.09	2.19	0.10

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

CLP: not classified
DSD: not classified