Trichloroethylene

Endpoint summary

Description of key information

Human experience and limited animal experimental data indicate that liquid trichloroethylene is a skin and eye irritant.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

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:

other: Guideline study, GLP status not reported, available as unpublished report, fully adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

not specified

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

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

other: stabilized with thymol

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
- Concentration (if solution): 10 mg/l

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 (trichloroethylene tested individually): 3
Experiment 2 (trichloroethylene 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)

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48, 72 hours after application

Score:

4

Max. score:

4

Reversibility:

other: at day 16, the mean score was 0.3

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48, 72 hours after application

Score:

1.4

Max. score:

4

Reversibility:

fully reversible within: 16 days

Irritation parameter:

overall irritation score

Basis:

other: The Primary Irritation Index was calculated by combining the scores for erythema/eschar formation and oedema after 24, 48 and 72 hours.

Time point:

other: 24, 48 and 72 hours after application

Score:

5.5

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48, 72 hours after application

Score:

3.8

Max. score:

4

Reversibility:

other: At day 16, the mean score was 0.3

Remarks on result:

other: trichloroethylene examined simultaneously with three other solvents on separate skin areas

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48, 72 hours after application

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 16 days

Remarks on result:

other: trichloroethylene examined simultaneously with three other solvents on separate skin areas

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

other: The Primary Irritation Index was calculated by combining the scores for erythema/eschar formation and oedema after 24, 48 and 72 hours.

Time point:

other: 24, 48 and 72 hours after application

Score:

5.4

Remarks on result:

other: trichloroethylene examined simultaneously with three other solvents on separate skin areas

Irritant / corrosive response data:

Experiment 1 (rabbits treated with only one test substance):
Generally the following skin reactions were observed at one or more obervation time points, up to 72 hours afer treatment: well-defined erythema, very slight or slight ischemic necrosis (not after 4 hours) and very slight incrustation (after 72 hours only).
After 9 days, very slight erythema (in two rabbits) and very slight oedema, slight or severe scaliness and very slight, slight or moderate incrustation (in all three rabbits); after 16 days, very slight erythema (in one rabbit).

Experiment 2 (rabbits treated with four test substances at the same time):
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, very slight ischemic necrosis (not after 4 hours) and slight scaliness or slight incrustation (mainly after 72 hours).
After 9 days, very slight or well-defined erythema (in two rabbits), very slight or slight oedema (in all three rabbits), severe scaliness (in one rabbit) and moderate incrustation (in all three rabbits). After 16 days: very slight erythema (in one rabbit) and decreased hair growth (in two rabbits).
After five weeks all effects had cleared completely.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

A reliable skin irritation study is available with positive results. Furthermore, there are indications from human experience and studies in animals that both single and repeated dermal exposure to trichloroethylene can be irritating to the skin, as is to be expected given the defatting properties of the substance, and that it should therefore be classified for skin irritation.

Limited human and animal data is available on eye irritating properties, however, the data provide sufficient basis to consider the substance an eye irritant.

Justification for selection of eye irritation endpoint:
No specific study is available, however based on human experience trichloroethylene is classified as an eye irritant.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

From the data available, it is apparent that trichloroethylene should be classified for skin irritation according to Directive 67/548/EEC (Xi; R38) and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 (H315 – Skin Irrit. 2).

Also, from the data which are available, it can be concluded that trichloroethylene should be classified for eye irritation according to Directive 67/548/EEC (Xi; R36) and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 (H319 – Eye Irrit. 2).