Propanoic acid, 2-hydroxy-, ammonium salt (1:1), (2S)-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2003-07-25 to 2003-10-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Propanoic acid, 2-hydroxy-, ammonium salt (1:1), (2S)-

EC Number:

604-012-2

Cas Number:

137296-15-2

Molecular formula:

C3H9O3N

IUPAC Name:

Propanoic acid, 2-hydroxy-, ammonium salt (1:1), (2S)-

Specific details on test material used for the study:

- Name of test material (as cited in study report): Ammonium-S-Lactate
- Physical state: clear colourless liquid
- Analytical purity: ca. 70 %
- Composition of test material, percentage of components: ca. 70 % ammonium lactate, ca. 30 % water
- Lot/batch No.: 2991200039
- Expiration date of the lot/batch: 2005-02-10
- Stability under test conditions: stable
- Storage condition of test material: at room temperature in the dark

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Kisslegg, Germany
- Age at study initiation: at least 6 weeks
- Weight at study initiation: at least 1.0 kg
- Housing: individually in labelled cages with perforated floors
- Diet: standard laboratory rabbit diet approx. 100 g per day; in addition, pressed hay was provided twice a week, ad libitum
- Water: tap-water (quarterly analysis of quality available at test site), ad libitum
- Acclimation period: at least 5 days before start of treatment under laboratory conditions

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.1-23.9 °C
- Humidity (%): 44-81 %; according to the test laboratory cleaning procedures in the room might have caused the temporary fluctuations above the optimal level of 70 % for relative humidity. Based on laboratory historical data these conditions were considered not to have affected the study integrity.
- Air changes (per hr): 15 per hour
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): 70 %

Duration of treatment / exposure:

4 h

Observation period:

1, 24, 48 and 72 h

Number of animals:

3 males

Details on study design:

TEST SITE
- Area of exposure: 2 × 3 cm (6 cm²)
- Type of wrap if used: the test substance was applied to the skin of one flank, using a metalline patch (2 x 3 cm); the patch was mounted on Micropore tape, which was wrapped around the abdomen and secured with Coban elastic bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the dressing was removed and the skin was cleaned of residual test substance using water
- Time after start of exposure: 4 hours

SCORING SYSTEM:
The irritation was assessed according to the following numerical scoring system. At each observation, the highest scores given were recorded:

Erythema and eschar formation:
No erythema .......................................................................................................................... 0
Very slight erythema (barely perceptible) .............................................................................1
Well-defined erythema ......................................................................................................... 2
Moderate to severe erythema ............................................................................................. 3
Severe erythema (beet redness)* ....................................................................................... 4
* Where signs of necrosis or corrosion (injuries in depth) prevent erythema scoring, the maximum grade for erythema(= 4) is given.

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 millimeter) .................................................................. 3
Severe oedema (raised more than 1 millimeter and extending beyond the area of exposure) 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible within:

Remarks:

24 h

Remarks on result:

probability of weak irritation

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 5

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

Irritation (please refer to Table 1 in box " Any other information on results incl. tables"):
Four hours exposure to 0.5 mL of the test item resulted in very slight erythema in the treated skin-area of one rabbit, which had resolved within 24 hours.

Corrosion:
There was no evidence of a corrosive effect on the skin.

Other effects:

Colouration:
No staining of the treated skin by the test substance was observed.

Toxicity/mortality:
No symptoms of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Any other information on results incl. tables

Table 1: Individual skin irritation scores

Animal #	513 (sentinel)			537			538
Time after exposure	Erythema	Oedema	comments	Erythema	Oedema	comments	Erythema	Oedema	comments
1 hour	1	0	-	0	0	-	0	0	-
24 hours	0	0	-	0	0	-	0	0	-
48 hours	0	0	-	0	0	-	0	0	-
72 hours	0	0	-	0	0	-	0	0	-

 

 Table 2: Mean value irritation scores

Animal #	Mean 24 - 72 hrs
	Erythema	Oedema
513	0	0
537	0	0
538	0	0

 

Table 3: Animal specifications

Animal #	Sex	Age at start (weeks)	Body weights (g)
			prior to application	at termination
513	M	8-10	1883	1998
537	M	7-9	1407	1509
538	M	7-9	1481	1601

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute dermal irritation/corrosion study conducted according to OECD 404, the test item was found to be non-irritating.

Executive summary:

In a primary dermal irritation study (OECD guideline 404), three male New Zealand white rabbits were dermally exposed to 0.5 mL of the test item (70% solution) for 4 hours to a body surface area of 6 cm² under semi-occlusive conditions. Animals then were observed for 1, 24, 48 and 72 hours after removal of the dressings and test substance. The test item did not cause any skin effects, except a very slight erythema in the treated skin-area of one rabbit, which had resolved within 24 hours. Based on the results, the test item is considered to be non-irritating.