α,α,α-trifluoro-3-tolyl isocyanate

Endpoint summary

Description of key information

2 in-vivo studies for skin irritation/corrosion and eye irritation from a secondary source were available.
Additionally for the evaluation of the skin corrosion/irritating properties of m-trifluoromethylphenylisocyanate (alpha,alpha,alpha-trifluoro-3-tolyl isocyanate) an artificial 3D-skin model test according to OECD TG 439 was used.
For assessing ocular irritation of compounds an in-vitro study using a human epithelial corneal cell model was conducted. The model used is standardized and commercially available (SkinEthic™ Human Corneal Epithelial Model (HCE); SkinEthic, France). Further m-trifluoromethylphenylisocyanate (alpha,alpha,alpha-trifluoro-3-tolyl isocyanate) was tested using the Hen's egg chorioallantoic membrane (HET-CAM) test according to the ICCVAM Test Method Evaluation Report: Appendix G: ICCVAM Recommended Protocol for Future Studies Using the Hen's Egg Test-Chorionallantoic Membrane (HET-CAM) Test method, November 2006.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study

Qualifier:

according to guideline

Guideline:

other: OECD TG 431

Qualifier:

according to guideline

Guideline:

other: EU Method B.40 (Skin Corrosion)

Principles of method if other than guideline:

The experiment was carried out on a reconstructed human epidermis EST-1000 (CeIiSystems, St. Katharinen, Germany)

GLP compliance:

yes

Species:

other: not applicable - in-vitro 3D skin corrosion test

Strain:

other: not applicable - in-vitro 3D skin corrosion test

Type of coverage:

other: not applicable - in-vitro 3D skin corrosion test

Preparation of test site:

other: not applicable - in-vitro 3D skin corrosion test

Vehicle:

other: not applicable - in-vitro 3D skin corrosion test

Controls:

other: not applicable - in-vitro 3D skin corrosion test

Duration of treatment / exposure:

After an exposure period of 3 or 60 minutes, followed by a post-treatment incubation period of about 3 hours, the cell viability was measured

Observation period:

not applicable - in-vitro 3D skin corrosion test

Number of animals:

not applicable - in-vitro 3D skin corrosion test

Irritation / corrosion parameter:

other: other: cell viability

Value:

93.6

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 3 min. Max. score: 100.0. Reversibility: other: not applicable - in-vitro 3D skin corrosion test. Remarks: non corrosive - scores in [%] viability.

Irritation / corrosion parameter:

other: other: cell viability

Value:

60.67

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 60 min. Max. score: 100.0. Reversibility: other: not applicable - in-vitro 3D skin corrosion test. Remarks: non corrosive - scores in [%] viability.

Compound                                   [%] Cell viability 3 min       [%] Cell viability 60 min      Classification*

m-Trifluoromethylphenylisocyanate              93.60                                      60.67               Non-corrosive                   

Negative control                                          100                                          100              Negative control

*: Classification was done in accordance with the existing guideline and

internationally accepted protocols, i.e. evaluation of LD50 values after 3 min. and/or less than 15% viability after a 60 min. incubation period.

Interpretation of results:

other: non corrosive

Executive summary:

This study for predicting non-specific, corrosive potentials of compounds by using reconstructed human skin (RHS) was performed in 2011. The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, St. Katharinen, Germany) for detection of topically applied skin corrosives with the test item m-trifluoromethylphenylisocyanate.

Corrosive skin effects of substances are defined as irreversible damage of skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test substance for up to four hours. In vivo corrosive reactions are typified by ulcers, bleeding, and bloody scabs.

A 100% concentration was tested on the skin/epidermal equivalents in triplets. For the determination of time related cytotoxic effects the incubation periods were 3 min. and 60 min., respectively. By this the study, was conducted in accordance with the OECD 431 guideline as well as with an EC guideline (amending Council Directive 67/548/EEC, B.40 Skin corrosion) using the test item concentrations and incubation periods recommended there. These tests are also related to the revised OECD 404 guideline "Acute Dermal Irritation/Corrosion".

To check the reliability of this test procedure a blinded positive/negative control study is conducted at regular intervals in the lab. This reliability check is always performed by two technicians, two laboratories in parallel using the same batches of the control test items.

The test item was applied at a 100% concentration, i.e. 50 µl per insert.

The MTT (Methylthiazoletetrazolium) method has determined the following values of viability after 3 min. or after 60 min. of incubation: 94% and 61% (rounded), respectively. Thus, the results show that no corrosive property of the test item was determined by the assay used.

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study

Qualifier:

according to guideline

Guideline:

other: EU Test Method B.46

Principles of method if other than guideline:

The experiment was carried out on a reconstructed human epidermis EST-1000 (CeIiSystems, St. Katharinen, Germany)

GLP compliance:

yes

Species:

other: not applicable - in-vitro 3D skin irritation test

Strain:

other: not applicable - in-vitro 3D skin irritation test

Type of coverage:

other: not applicable - in-vitro 3D skin irritation test

Preparation of test site:

other: not applicable - in-vitro 3D skin irritation test

Vehicle:

other: not applicable - in-vitro 3D skin irritation test

Controls:

other: not applicable - in-vitro 3D skin irritation test

Duration of treatment / exposure:

After an exposure period of 20 minutes, followed by a 42 hours post-treatment incubation period, the cell viability was measured

Observation period:

not applicable - in-vitro 3D skin irritation test

Number of animals:

not applicable - in-vitro 3D skin irritation test

Irritation / corrosion parameter:

other: other: cell viability

Value:

8.62

Remarks on result:

other:

Remarks:

Basis: mean. Time point: ca. 42 hours. Max. score: 100.0. Reversibility: other: not applicable - in-vitro 3D skin irritation test. Remarks: irritant - scores in [%] viability. (migrated information)

Compound                                    Cell viability [%]        Classification*

m-Trifluoromethylphenylisocyanate       8.62                       Irritant (I)

Positive control                                   4.06                       Irritant (I)

Negative control                            100.00                    Non irritant (NI)

*: Classification was done in accordance with EU Test Method B.46.

In vitro result                      In vivo prediction

mean tissue viability<50        Irritant (I)

mean tissue viability > 50       Non-irritant (NI)

(I): Irritant , R38 = Skin irritation category 2, H315

(NI): Non – irritant = no skin irritation category

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Executive summary:

This study which allows the hazard identification of irritant substances in accordance with UN GHS category 2, was performed in 2011. The experiment was carried out according to EU Test Method B.46 using commercially available reconstructed human epidermis (RHS) model EST-1000 (CellSystems, St.Katharinen, Germany).

Undiluted m-Trifluoromethylphenylisocyanate was applied topically to the RHS model, i.e. 30 µl per insert

After an exposure period of 20 minutes, followed by a 42 hours post-treatment incubation period, the cell viability was measured to be 9% (rounded) in the MTT (Methylthiazoletetrazolium) conversion assay.

The results of the concurrent negative control (NC, 0.9% NaCl) and positive control (PC, 5% SDS) demonstrated the viability (NC) and sensitivity (PC) of the test model.

Thus, the results show that m-Trifluoromethylphenylisocyanate is considered to have skin irritation category 2.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study

Principles of method if other than guideline:

In vitro study for assessing ocular irritation of compounds using a human epithelial corneal cell model. The model used is standardized and commercially available (SkinEthic™ Human Corneal Epithelial Model (HCE); SkinEthic, France).

GLP compliance:

yes

Species:

other: not applicable - human corneal epithelial model (HCE)

Strain:

other: not applicable - human corneal epithelial model (HCE)

Vehicle:

other: not applicable - human corneal epithelial model (HCE)

Controls:

other: not applicable - human corneal epithelial model (HCE)

Duration of treatment / exposure:

After an exposure period of 60 minutes, followed by a 16 hours post-treatment incubation period, the cell viability was measured

Observation period (in vivo):

not applicable - human corneal epithelial model (HCE)

Number of animals or in vitro replicates:

not applicable - human corneal epithelial model (HCE)

Irritation parameter:

other: cell viability

Run / experiment:

60 minutes followed by a 16 h post-treatment period

Value:

29.21

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: irritant - scores in [%] viability

A test substance is predicted to be an ocular irritant if the mean relative tissue viability (%) exposed to the test substance is<50%.

As can be seen from the information in the Table below the test substance

m-Trifluoromethylphenylisocyanate was detected as irritant to the cornea epithelium in this test model.

Compound                                   Cell viability [%] Evaluation

m-Trifluoromethylphenylisocyanate      29.21               irritant

Positive control                                   20.04              irritant

Negative control                               100.00             non-irritant

Interpretation of results:

irritating

Remarks:

Migrated information

Executive summary:

This in vitro study for assessing ocular irritation of compounds using a human epithelial corneal cell model was performed in 2011. The model used is standardized and commercially available (SkinEthicTM Human Corneal Epithelial Model (HCE); SkinEthic, France).

Undiluted m-trifluoromethylphenylisocyanate was applied topically to the HCE tissue, i.e. 30 mg per insert. (plus 30 µl PBS to moisten and ensure good contact with the skin; three replicates)

After an exposure period of 60 minutes, followed by a 16 hours post-treatment incubation period, the cell viability was 2% (rounded) as measured by a MTT conversion assay.

The results of the concurrent negative (NC, PBS) and positive control

(PC, 1H-1,2,4-Triazole-3-thiol) demonstrated the viability (NC) and sensitivity (PC) of the test model.

The results show that m-trifluoromethylphenylisocyanate is predicted as ocular irritant under the conditions of this test method.

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study

Qualifier:

according to guideline

Guideline:

other: ICCVAM Test Method Evaluation Report: Appendix G: ICCVAM Recommended Protocol for Future Studies Using the Hen's Egg Test-Chorionallantoic Membrane (HET-CAM) Test method, November 2006

Principles of method if other than guideline:

The hen's egg test was modified as an alternative to the rabbit's eye irritation/corrosion test. The extra-embryonal blood vessel system of the incubated chicken egg is used to observe the acute toxicological effects of irritant/corrosive test substances. This test was performed by using the chorionallantoic membrane (HET-CAM, 8d incubation) of chicken eggs

GLP compliance:

yes

Species:

other: not applicable (in vitro study)

Strain:

other: not applicable (in vitro study)

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable (in vitro study)

Duration of treatment / exposure:

single treatment

Observation period (in vivo):

Effects are measured by the onset of haemorrhage, vessel lysis or coagulation during the first 300 seconds after application

Number of animals or in vitro replicates:

not applicable - in vitro study (4 eggs were used)

Irritation parameter:

other: irritation score

Run / experiment:

IS = 5 x (301-sec H)/300 + 7 x (301- sec L)/300 + 9 x (301- sec C)/ 300

Value:

1

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: H= observed start in seconds of haemorrhage reactions L= observed start in seconds of vessel lysis, strong haemorrhage C= observed start in seconds of blood - coagulation, albumen - coagulation

                                                       HET-CAM        Index

Negative Control NaCl 0.9%              0              Non irritant

Positive Control SDS 1%                    9              Strong irritant

m-Trifluoromethylphenylisocyanate       1               Slight irritant

Interpretation of results:

irritating

Remarks:

Migrated information

Executive summary:

Hen`s egg tests are used to determine the potential irritant/corrosive property of a test compound using an in vitro alternative to the Draize methodology (OECD405).

m-Trifluormethylphenylisocyanat was tested by observing possible adverse changes after application onto the chorioallantoic membrane (HET-CAM).

After the application of the test item blood vessels and albumen were examined and scored for the following irritant effects: vasodilation, slight haemorrhage; vessel lysis, strong haemorrhage; blood coagulation, albumen coagulation for a period of 300 seconds.

300 µl of the test item was applied per egg directly on the chorioallantoic membrane.

m-Trifluormethylphenylisocyanat was identified as “slight irritant” to the chorioallantoic membrane (Irritation Score (IS) = 1) under the conditions of this assay.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

In an occlusive patch test with an exposure period of 24 hours and an eye irritation study according an unspecified FDA guideline alpha,alpha,alpha-trifluoro-3-tolyl isocyanate was irritatiant to the skin and eyes. From these studies no score values are availabe.

In the in-vitro 3D skin irritation test m-trifluoromethylphenylisocyanatewas irritating - but not corrosive.

In the reconstituted human ocular epithelia (SkinEthic™ Human Corneal Epithelial Model (HCE); SkinEthic, France) m-trifluoro-methylphenylisocyanate was irritant. Also in the HET-CAM test using the chorionallantoic membrane (HET-CAM, 8d incubation) of chicken eggs m-trifluoromethylphenylisocyanate was irritant.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

Due to the results of the skin irritation studies Skin Irrit. 2; H 315 is justified.

Due to the results of the eye irritation study Eye Dam. 1; H 318 is adequate.

In addition, respiration irritational effects were reported. Therefore STOT Single Exp. 3 ( H335: May cause respiratory irritation) is applicable.