Phenyl isocyanate

Endpoint summary

Description of key information

Skin irritation: in 2 valid studies phenyl isocyanate was irritant/corrosive to the skin and in another study phenyl isocyanate was not irritating to the skin.
Eye irritation: in one valid study phenyl isocyanate was highly irritating to the eye.

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

according to guideline

Guideline:

other: Code of Federal Regulations, Title 16, Section 1500.41

Principles of method if other than guideline:

500 µl of phenyl isocyanate was applied on a 2.5 x 2.5 cm² area at the shaved (one side) and scarified (other side) trunk of 6 rabbits and fixed for 24 h. Reading was carried out 24, 48 and 72 h after start of application.

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Type of coverage:

semiocclusive

Preparation of test site:

other: shaved and scarified

Vehicle:

unchanged (no vehicle)

Controls:

not required

Duration of treatment / exposure:

24 hours

Observation period:

8 days

Number of animals:

6 animals

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24, 72 h

Score:

>= 2

Max. score:

8

Reversibility:

not fully reversible within: 8 days

Remarks on result:

other: no erythema score available after 24 and 72 h due to white discoloration of the skin

Irritant / corrosive response data:

Erythema score = 4 (after 8 days), edema score = 4 (24, 72 hours and 8 days).

Other effects:

White discoloration of the skin within 24 hours. Dryness, folding and red-brownish discoloration of the skin after 72 hours. Dry eschar formation after 8 days and beginning of ablation. No hair growth under eschar.

Phenyl isocyanate is strong irritant/corrosive to the skin.

Interpretation of results:

Category 1 (corrosive) based on GHS criteria

Conclusions:

Phenyl isocyanate was regarded as strong irritant/corrosive to the skin. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Skin Corr. 1 is justified.

Executive summary:

500 µl of the phenyl isocyanate was applied on a 2.5 x 2.5 cm² area at the shaved (one side) and scarificed (other side) trunk of 6 rabbits and fixed for 24 h. Reading was carried out 24 and 72 h after start of application.

Within 24 hours a white discoloration of the skin occurs, followed by dryness, folding of the skin after 72 hours. A dry eschar formation after 8 days and beginning of ablation was observed. No hair growth under the eschar.

The primary irritation index was> 2.0. Phenyl isocyanate was regarded as strong irritant/corrosive to the skin.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye 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

Qualifier:

according to guideline

Guideline:

other: Code of Federal Regulations, Title 16, Section 1500.42

Principles of method if other than guideline:

100 µl phenyl isocyanate was applied into the conjunctival sac of the right eye of 6 rabbits. Reading was carried out 24, 48 and 72 h after start of application of the test substance.

GLP compliance:

not specified

Species:

rabbit

Strain:

New Zealand White

Vehicle:

unchanged (no vehicle)

Controls:

not required

Duration of treatment / exposure:

8 days (eye was not washed after application of the test substance)

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

6 animals

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24, 48, 72 h

Score:

49.8

Max. score:

110

Reversibility:

not fully reversible within: 8 days

Irritant / corrosive response data:

Eight days after application of the test substance, no repair of the eye damages was observed, with a trend for deterioration. Phenyl isocyanate is therefore highly irritant to the eyes.

Other effects:

No repair of the effects within 8 days, with a trend for further deterioration

Eight days after application of the test substance, no repair of the eye damages was observed, with a trend for deterioration.

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

Eight days after application of the test substance, no repair of the eye damages was observed, with a trend for deterioration. Phenyl isocyanate is therefore classified as highly irritant. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Eye Damage 1 is justified.

Executive summary:

100 µl phenylisocyanate was applied into the conjunctival sac of the right eye of 6 rabbits. Reading was carried out 24, 48 and 72 h after start of application of the test substance. A primary irritation score of 49.8 (of 110) was found. Eight days after application of the test substance, no repair of the eye damages was observed, with a trend for deterioration. Phenyl isocyanate is therefore classified as highly irritant.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

In a guideline study according Code of Federal Regulations, Title 16, Section 1500.41, phenyl isocyanate was found strong irritant/corrosive. In 2 other study phenyl isocyanate was found irritating to skin or not irritating to skin.

In a guideline study according Code of Federal Regulations, Title 16, Section 1500.41, phenyl isocyanate was strong irritant to eyes. These findings were supported by 2 other study where phenyl isocyanate was corrosive (5 minute exposure); corrosive and extremely irritant (24 h exposure)

In addition, several acute inhalation toxicity studies reported respiration irritating effects.

Justification for classification or non-classification

Skin irritation: in 2 valid studies phenyl isocyanate was irritant/corrosive to the skin and in another study phenyl isocyanate was not irritating to the skin. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Skin Corr. 1C is justified on a weight-of-evidence consideration.

Eye irritation: In one valid study phenyl isocyanate was highly irritating to the eye. Eight days after the application of the test substance, no repair of the eye damages was observed with a trend for deterioration. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as Eye Damage 1 is justified.

In addition, several acute inhalation toxicity studies reported respiration irritating effects. According to CLP classification criteria (Regulation (EC) No 1272/2008) a classification as STOT SE 3 ( H335: May cause respiratory irritation) is justified.