Malonic acid

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Study was conducted prior to GLP and OECD guideline implementation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1974

Report date:

1974

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: US DOT (Transport-Classification) Guidelines

Principles of method if other than guideline:

The study was performed before GLP- and OECD-testing guidelines were available and in force. The intact and abraded skin of 120 albino rabbits was employed for this study. A series of 6 rabbits was used for testing each substance.

GLP compliance:

no

Remarks:

Study carried out prior to introduction of GLP

Test material

Test material information

Constituent 1

Reference substance name:

Malonic acid

EC Number:

205-503-0

EC Name:

Malonic acid

Cas Number:

141-82-2

Molecular formula:

C3H4O4

IUPAC Name:

propanedioic acid

Test material form:

solid: crystalline

Details on test material:

Batch No: 20160723Purity: 99.5 %

Test animals

Species:

rabbit

Strain:

not specified

Test system

Type of coverage:

occlusive

Preparation of test site:

abraded

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5g

Duration of treatment / exposure:

4 hours

Observation period:

4, 24 and 48 hours

Number of animals:

6

Details on study design:

A series of 6 rabbits was used for testing this substance. Hair was clipped using angora clippers. Four areas of the back, placed approximately 10 cm apart, were designated for the application of the patches. Areas 2 and 3 were abraded by making 4 epidermal incisions (two perpendicular to two others). The patches consisted of 1.5 inch x 1.5 inch 12 ply gauze squares. The patches were secured to the area by thin bands of adhesive tape (occlusive application). The material to be tested (0.5 g) was introduced beneath the patch. The entire trunks of the animals were then wrapped in clear plastic trunk bands. Upon removal of the pactches, the resulting reactions were evaluated on the basis of weighted scores.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Score:

1.3

Reversibility:

fully reversible within: 48 hours

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48 h

Score:

0.6

Max. score:

2

Reversibility:

fully reversible within: 48 hrs

Results 3

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48 h

Score:

0

Max. score:

0

Any other information on results incl. tables

Primary Irritation Study

		Erythema-Eschar observation			Edema observation
Rabbit #	Skin	4 hr	24 hr	48 hr	4 hr	24 hr	48 hr	Average
1	Intact	2	1	0	0	0	0	1.17
	Abraded	2	1	0	1	0	0
2	Intact	2	1	0	0	0	0	1.33
	Abraded	2	1	0	1	1	0
3	Intact	2	1	0	0	0	0	1.0
	Abraded	2	1	0	0	0	0
4	Intact	2	2	0	0	0	0	2.0
	Abraded	2	2	1	1	1	1
5	Intact	2	1	0	0	0	0	1.0
	Abraded	2	1	0	0	0	0
6	Intact	2	1	0	0	0	0	1.17
	Abraded	2	1	0	1	0	0
Primary Irritation Index of Compound 1.3 (Mild primary irritant)

		Individual Scores – rabbit no
Skin Reaction	Reading (hours)	1	2	3	4	5	6
Erythema/Eschar	4	2	2	2	2	2	2
	24*	1	1	1	2	1	1
	48*	0	0	0	0	0	0
	72
Total of *		1	1	1	2	1	1
Mean values of *		0.5	0.5	0.5	1.0	0.5	0.5
Edema	4	0	0	0	0	0	0
	24*	0	0	0	0	0	0
	48*	0	0	0	0	0	0
	72	0	0	0	0	0	0
Total of *		0.0	0.0	0.0	0.0	0.0	0.0
Mean values of *		0.0	0.0	0.0	0.0	0.0	0.0

 

Overall mean of * for Erythema/Eschar = 0.6

Overall mean of * for Edema = 0.0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Only erythema (score 2) was noted in all 6 animals 4h hours after removal of the patch. After 24 hours, score 1 and 2 were still noted in the animals after removal of the patch. These findings were completely reversible within 48 hours. No oedema were observed during the test period. Therefore, Malonic acid is mildly irritating to rabbit skin (primary irritation index 1.3).

Executive summary:

Malonic acid is mildly irritating to rabbit skin, but not sufficient for CLP classification.