Tetrahydromethylphthalic anhydride

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

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Code of federal regulations, Title 16, Section 1500.41 (USA)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Tetrahydromethylphthalic anhydride

EC Number:

234-290-7

EC Name:

Tetrahydromethylphthalic anhydride

Cas Number:

11070-44-3

Molecular formula:

C9H10O3

IUPAC Name:

3a-methyl-3a,4,5,6-tetrahydro-2-benzofuran-1,3-dione

Details on test material:

- Name of test material (as cited in study report): methyl tetrahydrophthalic anhydride (grade A)(HN-2200)
- Lot/batch No.: 1852

Test animals

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

no details given

Test system

Type of coverage:

occlusive

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

no details given

Duration of treatment / exposure:

24 h treatment, patch test, 0.5 mL of test substances

Observation period:

24 hours and 72 hours

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: 1 inch x 1 inch
- Type of wrap if used: rubberized cloth
SCORING SYSTEM:
erythema and eschar formation
0: no erythema, 1: very slight erythema (barely perceptible), 2: Well-defined erythema, 3: moderate to severe erythema,
4: severe erythema (beet redness) to slight eschar formation (injuries in depth)
oedema formation
0: no oedema, 1: very slight oedema (barely perceptible), 2: slight oedema (edges of area well-defined by definite raising),
3: moderate oedema (raised approximately 1 millimeter),
4: severe oedema (raised more than 1 millimeter and extending beyond the area of exposure)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

3.5

Max. score:

8

Reversibility:

no data

Remarks on result:

other: time points: 24/72 h

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

no data

Remarks on result:

other: time points: 24/72 h (intact skin)

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

1.58

Max. score:

4

Reversibility:

no data

Remarks on result:

other: time points: 24/72 h (abraded skin)

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

1.92

Max. score:

4

Reversibility:

no data

Remarks on result:

other: time points: 24/72 h (intact skin)

Results 5

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

1.5

Max. score:

4

Reversibility:

no data

Remarks on result:

other: time points: 24/72 h (abraded skin)

Irritant / corrosive response data:

no details given

Other effects:

no details given

Any other information on results incl. tables

 

Rabbit no.	Reaction	24 hours		72 hours
		LEFT intact	RIGHT abraded	LEFT intact	RIGHT abraded
1	Erythema	2	2	2	2
	Oedema	2	2	2	2
2	Erythema	2	2	2	2
	Oedema	2	2	2	2
3	Erythema	2	2	3	1
	Oedema	2	2	3	1
4	Erythema	2	2	2	1
	Oedema	2	2	2	1
5	Erythema	2	2	2	0
	Oedema	2	2	2	0
6	Erythema	2	2	1	1
	Oedema	2	2	0	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Tetrahydromethylphthalic anhydride (MTHPA) is based on the available information (erythema score 2.00, oedema score 1.92) not a dermal irritant according to CLP (1272/2008/EEC).
In addition, the substance is also not classified according to ANNEX VI table 3.1 (GHS) and table 3.2 (DSD) of Regulation (EC) No 1272/2008 with regard to skin irritation.
The conditions of the available study are more stringed, in particular the 24 hour exposure period compared with 4 hours of current test methods (described in OECD TG 404), and are thus regarded as worst case scenario. In conclusion the substance is not classified skin irritating based on DSD and CLP.

Executive summary:

In a primary dermal irritation study, rabbits were dermally exposed to 0.5 ml of Methyl tetrahydrophthalic anhydride (MTHPA) for 72 hours to 1 inch x 1 inch of body surface area. Then animals were observed for 3 days. Irritation was scored by the method of patch test, code of Federal regulations, Title 16, Section 1500. 41 (Draize scaling).

A mean erythema score (24/72 h) calculated over all 6 animals for intact skin of 2 and for abraded skin of 1.58 was observed. The oedema score was determined to be 1.92 for intact skin and 1.50 for abraded skin.

Taking the test conditions into account, in particular the 24 hour exposure period compared with 4 hours of current test methods described in OECD TG 404, MTHPA has not to be classified and labelled as dermal irritant according to CLP (1272/2008/EEC), and according to 67/548/EEC (DSD).