dichloromethane; methylene chloride

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:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Dichloromethane

EC Number:

200-838-9

EC Name:

Dichloromethane

Cas Number:

75-09-2

Molecular formula:

CH2Cl2

IUPAC Name:

dichloromethane

Details on test material:

- Name of test material (as cited in study report): dichloromethane
- Analytical purity: > 99.95%
- Composition of test material, percentage of components: stabilized with amylene (2 mg/kg)
- Storage condition of test material: packed in dark coloured glass bottles and stored at room temperature until use.
- Other: Due to the low levels of stabilizer added to the solvents degradation may occur in contact with light metals, especially aluminium. Contact of the test material with metals was prevented at all times, before and during the experiments.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: ENKI-Konijnenfarm, Someren, The Netherlands
- Weight at study initiation: 2.5 - 3.0 kg
- Housing: individually, suspended, galvanized cages, fitted with a wire-mesh floor and front.
- Diet: ad libitum
- Water: ad libitum
- Acclimatization period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 +/- 3
- Humidity (%): >40
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

other: stabilized with amylene

Controls:

not required

Amount / concentration applied:

Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:

4 hours

Observation period:

at 1, 24, 48, 72 hours, 9 and 16 days after the 4 hour exposure period

Number of animals:

Experiment 1 (dichloromethane tested individually): 3
Experiment 2 (dichloromethane examined simultaneously with three other solvents on separate skin areas): 3

Details on study design:

TEST SITE
- Area of exposure: 1 inch x 1 inch
- Type of wrap if used: patches fixed to the application sites by means of adhesive tape and the entire trunk of each rabbit was wrapped with an impervious material.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): with lukewarm water and soap
- Time after start of exposure: 4 hours

SCORING SYSTEM:
Method of Draize et al. (1944)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 4749

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

fully reversible within: 16 days

Results 2

Irritation parameter:

edema score

Basis:

animal: 4749

Time point:

24/48/72 h

Score:

1.33

Max. score:

4

Reversibility:

fully reversible within: 16 days

Results 3

Irritation parameter:

erythema score

Basis:

animal: 4750

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 16 days

Remarks:

score 1 on day 16

Results 4

Irritation parameter:

edema score

Basis:

animal: 4750

Time point:

24/48/72 h

Score:

1.67

Max. score:

4

Reversibility:

fully reversible within: 16 days

Results 5

Irritation parameter:

erythema score

Basis:

animal: 4751

Time point:

24/48/72 h

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 16 days

Remarks:

score 1 on day 16

Results 6

Irritation parameter:

edema score

Basis:

animal: 4751

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 16 days

Remarks:

score 1 on day 16

Irritant / corrosive response data:

Experiment 1: Generally the following skin reactions were observed at one or more observation time points, up to 72 hours after treatment: well-defined or moderate erythema, very slight or slight oedema, slight focal haemorrhages (not after 72 hours), very slight ischemic necrosis (not after 4 hours), slight or moderate scaliness (after 48 and 72 hours), and slight incrustation (after 72 hours only). After 9 days, very slight erythema and very slight oedema (in all three rabbits), moderate or severe scaliness and very slight or slight incrustation (in two rabbits), and some superficial scars (in one rabbit); after 16 days, very slight erythema with or without very slight oedema (in two rabbits).

Experiment 2: Generally the following skin reactions were observed at one or more observation time points, up to 72 hours after treatment: well-defined or moderate erythema, very slight or slight oedema and very slight ischemic necrosis (not after 4 hours). After 9 days, well-defined erythema and very slight oedema (in two rabbits), slight or slight to moderate scaliness (in all three rabbits) and very slight incrustation (in one rabbit); after 16 days no dermal effects.

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

According to the EEC-standards (as published in the Official Journal of the European Communities, L257, Volume 26, 16 September 1983) dichloromethane is irritating to skin but not corrosive