2,2-dimethylpropane-1,3-diyl cyclohex-4-ene-1,2-dicarboxylate

Endpoint summary

Description of key information

The substance was considered to be non-irritant to the skin  based on the results of an in vitro assay performed according to OECD 439 and due to the fact that no evidence of skin irritation was observed in a OECD guideline acute dermal rat study with a 24-hour semi-occlusive exposure.
An in vitro Bovine Corneal Opacity and Permeability Test was performed according to OECD 437 as well as an In vivo OECD 405 acute eye irritation study to determine to irritation potential to the eye.  

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD test guideline, “In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method” (TG 439).

Deviations:

no

GLP compliance:

yes

Species:

other: Study was in vitro.

Strain:

not specified

Details on test animals or test system and environmental conditions:

Study was conducted in vitro.

Controls:

no

Amount / concentration applied:

30 ul neat test substance

Duration of treatment / exposure:

60 minutes

Observation period:

42 +/- 2 hr

Number of animals:

None, study conducted in vitro.

Details on study design:

The EpiDerrn human skin model tissues were stored at 2-8°C until use. On the day prior to testing, EpiDermTM Maintenance Medium was set to room temperature prior to use. Nine-tenths mL of Maintenance Medium were aliquotted into the appropriate wells of 6-well plates. Each 6-well plate was labeled with the test article, positive control, or negative control. The EpiDermTM tissues were incubated at 37±1°C in a humidified atmosphere of 5±t% CO2 in air (standard culture conditions) for 18 ±3 hours to acclimate the tissues.

The definitive assay included a negative control and a positive control. The negative control was 30 uL of sterile, Calcium and Magnesium Free Dulbecco’s Phosphate Buffered Saline (CMF-DPBS) and the positive control was 30 uL of 5% Sodium Lauryl Sulfate (SLS). After the overnight incubation for 18 ±3 hours, the 6-well plates containing the EpiDermT’ tissues were removed from the incubator and placed at room temperature for at least 5 minutes prior to dosing.

The EpiDermTM tissues were treated in triplicate with the test substance, negative control and positive control for 60 ±1 minutes. All of plates were transferred to the incubator for 35 ± 1 minutes at standard culture conditions. After 35 minutes, all of the plates were removed from the incubator, placed into the laminar flow hood and kept at room temperature until the exposure period was completed for the first dosed tissue. After 60 ± 1 minutes of of treatment, the tissues were rinsed with sterile, CMF-DPBS.

The tissue inserts were transferred to new 6-well plates containing 0.9 mL of flesh warmed (to 37°C) Maintenance Medium. The tissue surface was carefully blotted with sterile cotton-tipped applicators to remove any excess moisture, and the tissue surface was visually observed for residual test substance using a dissecting scope. Since residual test substance was observed, sterile cotton-tipped applicators pre-moistened with CMF-DPBS were used to attempt to remove any residual test substance from the tissue surface. A minimal amount of residual test substance remained after attempting to remove with the cotton swab. The tissues were then placed into the incubator at standard culture conditions for a post-treatment expression incubation of 42 ± 2 hours.

After the total 42 ± 2 hours post-exposure expression incubation, the 6-well plates were removed from the incubator. Each tissue was blotted on a sterile paper towel and transferred to an appropriate well containing 0.3 mL of MTT (3-[4,5 - dirnethylthiazol-2-ylj - 2,5 - diphenyltetrazolium bromide)’ solution. The 24-well MTT plates were incubated at standard culture conditions for 3 +/- 0.1 hours.

After the 3 ± 0.1 hour incubation, the EpiDermTM tissues were submerged, gently swirled, and rinse media decanted in a beaker containing approximately 150 mL of CMF-DPBS three times. The tissue was then blotted on absorbent paper, and transferred to a prelabelled 24-well plate containing 2.0 mL of isopropanol in each designated well. The plates were covered with parafllm and shaken for at least 2 hours at room temperature to extract the MMT. The absorbance at 570 nm (0D570) of each extract was measured with a Molecular Devices Vmax plate reader with the AUTOMIX function selected.

Irritation / corrosion parameter:

% tissue viability

Value:

6.7

Remarks on result:

other:

Remarks:

Basis: mean. Time point: One hr.. Reversibility: no data Study was conducted in vitro.. Remarks: The test substance treated EpiDerm tissue relative percent viability was 6.7%. . (migrated information)

Other effects / acceptance of results:

Mean relative test substance treated EpiDerm tissue viability was 6.7%.

Interpretation of results:

not irritating

Remarks:

Migrated information Due to technical difficulties in removal of the test substance from the EpiDerm tissue the results do not support a conclusion of irritation. Criteria used for interpretation of results: other: published

Conclusions:

The mean relative percent viability of the test substance treated EpiDerm tissue was 6.7%. However, due to technical difficulties in the removal of the test substance from the tissue the exposure was prolonged. Furthermore, physical trama to the tissues may have occured when attempting to remove test substance from the exposed tissue. These two confounding factors are likly to have contiributed to the reduced viabilty of test substance treated EpiDerm tissues. Therefore, the data are not useful for accessing the potential skin irritating potential of the test substance.

Executive summary:

The test substance, 1,2,3,6 -Tetrahydrophthalic anhydride, oligomeric reaction products with 2,2 -dimethylpropane-1,3 -diol, when tested in an O.E.C.D. test guideline 439 Human skin irritation model was reported to have a mean relative tissue viability of 6.7%. However, due to technical difficulties in the removal of test substance from the exposed tissue surface, the data are not reliable for prediciting the skin irritating potential of the test substance.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye 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

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

The animals were acquired from Myrtle’s Rabbitry; Thompsons Station, Wills Point, TX and weighted 2.525-3.400 kg upon reciept. Each animal was housed in a suspended, wire bottom, stainless steel cage. The animal room maintained a 12-hour light/dark cycle, 10-12 air changes/hour
a temperature range of 18-25°C and relative humidity of 24-92%. The animals were offered PMI Feeds, Inc.TM Lab Rabbit Diet #532 1, ~8 oz. daily and Municipal water supply analyzed by TCEQ Water Utilities Division available ad libitum from automatic water system.

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.1 mL

Duration of treatment / exposure:

24 hr

Observation period (in vivo):

17 days, one animal only.

Number of animals or in vitro replicates:

3

Details on study design:

On Day 0, a dose of 0.1 mL of the undiluted test substance was placed into the conjunctival sac of the right eye of each animal by gently pulling the lower lid away from the eyeball to form a cup into which the test substance was dropped. The lids were gently held together for one second to prevent loss of material. The untreated left eyes served as comparative controls.

The grades of ocular reaction were recorded at 1, 24, 48 and 72 hours, at 4 and 7 days (all animals), as well as 10, 14 and 17 days (initial animal only) after treatment. The corneas of all treated eyes were examined immediately after the 24-hour observation with a fluorescein sodium ophthalmic solution. Any of the corneas that exhibited fluorescein staining at the 24-hour observation were re-examined with the fluorescein sodium ophthalmic solution at each consecutive observation until fluorescein staining of the cornea no longer occurred. All treated eyes were washed with room temperature DI water for one minute immediately after recording the 24-hour observation.

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24/48/72 h

Score:

ca. 37

Reversibility:

fully reversible within: 17 days.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.3

Reversibility:

not reversible

Remarks on result:

probability of moderate irritation

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.6

Reversibility:

fully reversible

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Reversibility:

fully reversible

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

10

Reversibility:

not reversible

Remarks on result:

probability of moderate irritation

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

10

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

10

Irritation parameter:

iris score

Basis:

animal #4

Time point:

24/48/72 h

Score:

0

Max. score:

10

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.66

Max. score:

3

Reversibility:

fully reversible

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

3

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible

Irritant / corrosive response data:

One animal had corneal opacity scores of 2-4 from days 7-14. This animal also exhibited Conjuntivae Chemosis and Discharge scores of 3 beginning at 24 hr and extending out to day 7. A second animal exhibited corneal opacity from 24 hr to day 4 with complete clearing by day 7. This animal also had Conjunctivae Redness scores of 2 ay 24-72 hr. The third animal exhibited some corneal opacity at 24-72 hr.

Interpretation of results:

moderately irritating

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

The test substance is a moderate eye irritant and requires Classification and Labeling in the EU.

Executive summary:

The test substance, 1,2,3,6-Tetrahydrophthalic anhydride, oligomeric reaction products with 2,2-dimethylpropane-1,3-diol, was evaluated for eye irritation potential in rabbits in an O.E.C.D. test guideline 405 study. Based upon the study results the test substance is judged to be a moderate eye irritant and requires Classification and Labeling in the EU.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

When evaluated in an OECD test guideline rat acute dermal study with a 24 -hour semi-occlusive exposure, the test substance caused no evidence of skin irritation. In an OECD test guideline 405 rabbit eye irritation study the test substance induced moderate to severe eye irritation. This findings is supported by the results of an in vitro BCOP study with a mean in viro score of 186 that predicts the test substance to be a severe eye irritant.

Effects on eye irritation: highly irritating

Justification for classification or non-classification

Based on the above stated assessment of the skin irritation potential the substance does not have to be classified for skin irritation according to Council Directive 2001/59/EC and according to CLP (Regulation (EC) No 1272/2008 Of the European parliament and of the Council.

Base on the above assessment of the eye irritation potential, the substance does have to be classified as R36 irritating to eye according to Council Directive 2001/59/EC and Category 2A ( H319: Causes serious eye irritation) according to CLP (Regulation (EC) No 1272/2008 Of the European parliament and of the Council.