Reaction mass of propylidynetrimethanol and 2-ethylpropane-1,3-diol and 5-ethyl-1,3-dioxane-5-methanol

Endpoint summary

Description of key information

There are no reliable studies available for the assessment of the skin irritation and eye irritation endpoints with the target substance, Polyol TD. Therefore, data from suitable read-across partners , 2 -ethylpropane-1,3 -diol (DMP) and 5 -ethyl-1,3 -dioxane-5 -methanol (CTF) was used to assess the skin and eye irritation potential of Polyol TD.

Only very slight skin irritation reactions were seen in a rabbit skin irritation study (according to OECD Guideline 404) performed with CTF. In addition, DMP was negative in an EpiSkin in vitro skin irritation assay performed according to OECD Guideline 439. Therefore, using the weight of evidence approach, Polyol TD is considered not irritating to the skin. Thus classification for skin irritation according to the CLP regulation 1272/2008 is not warranted.

An in vivo eye irritation study (according to OECD Guideline 405) with CTF indicates that this component is an eye irritant. Therefore, no additional testing is proposed for animal welfare reasons and it is assumed that Polyol TD is an eye irritant and therefore classification as Eye Irrit.2, H319 according to the CLP Regulation 1272/2008 is warranted.

For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

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:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Mean of three replicates after 15 minutes

Value:

87.91

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

The results of the assay were similar for the three viable EpiSkin® units dosed with DMP Tech. Exposure to DMP Tech resulted in a mean EpiSkin® viability of 87.91% ± 11.33% of the negative control value.

OTHER EFFECTS: No other effects reported.
- Visible damage on test system: After arrival at Charles River, the EpiSkin® kits were inspected for quality. The pH and temperature indicators were both acceptable.
- Direct-MTT reduction: The test was scored by visual assessment of the formation of the purple-coloured formazan. The positive control (eugenol) reduced the MTT solution to formazan almost immediately, generating a dark purple colour before incubation. The negative control (sterile, ultra-pure water) and DMP Tech did not reduce MTT to formazan after ca 3 h incubation.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The negative control results were within the acceptance criteria defined in the ECVAM validation SOP.
- Acceptance criteria met for positive control: The positive control results were within the acceptance criteria defined in the ECVAM validation SOP.

Interpretation of results:

GHS criteria not met

Conclusions:

In conclusion, DMP Tech is non-irritant (“no category” in accordance with CLP classification) when tested within the EpiSkin® in vitro skin irritation assay.

Executive summary:

In an in vitro skin iritation study performed according to OECD Guideline 439 (Reconstructed Human Epidermis Test Method), Dimethylolpropane Tech (DMP Tech) was tested in the EpiSkin® model for dermal irritation. Cell viability served as a parameter for irritation potential and was determined by the specific reduction of methylthiazoldiphenyl-tetrazolium bromide (MTT) to its formazan metabolite, which was measured spectrophotometrically. Irritant materials are identified by their ability to reduce cell viability below a threshold of 50% of the negative control value.

A volume of 10 µL DMP Tech was applied unchanged onto the exposed surface (ca. 0.38 cm²) of three viable EpiSkin® reconstructed human epidermis units derived from mammary/abdominal samples of healthy at an application rate was ca 26.3 μL/cm² for 15 minutes. DMP Tech was then washed from the surface of the EpiSkin® and the units returned to the incubator for a recovery period of ca 42 h.

After the recovery period, the skin units were transferred to assay medium containing MTT (0.3 mg/mL) and returned to the incubator for ca 3 h. Biopsies of the EpiSkin® membranes were then removed and extracted with acidic isopropanol.

Formazan production was assessed by measuring the optical density of the extract at 550 nm and the viability of each individual tissue was calculated as a percentage of the mean negative control viability. Exposure to DMP Tech resulted in an EpiSkin® viability of 87.91% ± 11.33% of the negative control value. The positive and negative controls, conducted in parallel, were within the defined acceptance criteria and demonstrated the efficacy of the test system.

In conclusion, DMP Tech is non-irritant (“no category” in accordance with GHS classification) when tested within the EpiSkin® in vitro irritation assay.

This information is used in a read-across approach in the assessment of the target substance. For justification of read-across please refer to the attached read-across report (see IUCLID section 13).

Reference 2

Endpoint:

skin irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0.3

Max. score:

4

Reversibility:

not reversible

Remarks on result:

other: Slight erythema seen in one animal from 24 hours onwards, still observed after 72 hours.

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

Very slight erythema was seen on one rabbit which persisted for the duration of the observation period; no signs of erythema or oedema were seen in any of the other three rabbits.

Other effects:

No other effects reported.

Table 2: Mean scores for skin irritation

Observation	0.5h	24h	48h	72h	Mean (24-72h)
Erythema	0.00	0.3	0.3	0.3	0.3
Oedema	0.00	0.00	0.00	0.00	0.00

Interpretation of results:

GHS criteria not met

Conclusions:

Under the given conditions, the test item is not irritating to the skin.

Executive summary:

In a primary dermal irritation study performed according to OECD Guideline 404, four female albino rabbits, weighing between 2.3 and 2.5 kg were dermally exposed to 0.5 ml of unchanged cyclic trimethylolpropane (5-Ethyl-1,3-dioxane-5-methanol) at the back of the animals to a clipped surface of 2.5 x 2.5 cm. Test sites were covered with a semi-occlusive dressing for 4 hours. Animals were then observed shortly after the removal of the test substance and 24, 48, and 72 hours after exposure. Irritation was scored by the method specified in OECD Guideline 404. Very slight erythema was seen on one rabbit which persisted for the duration of the observation period (24 -72 hours). No signs of erythema or oedema were seen in any of the other three rabbits.

Based on these results, it was concluded that the test item is not irritating to the skin of rabbits and therefore should not be classified as irritating to the skin according to CLP Regulation 1272/2008.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the attached read-across report (see IUCLID section 13).

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:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

1.75

Max. score:

4

Reversibility:

fully reversible within: 14 days

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0.08

Max. score:

2

Reversibility:

fully reversible within: 72 hours

Irritation parameter:

chemosis score

Remarks:

(Oedema of conjunctivae)

Basis:

mean

Time point:

24/48/72 h

Score:

2.08

Max. score:

4

Reversibility:

fully reversible within: 14 days.

Irritation parameter:

conjunctivae score

Remarks:

(Redness)

Basis:

mean

Time point:

24/48/72 h

Score:

2.83

Max. score:

3

Reversibility:

fully reversible within: 14 days

Irritant / corrosive response data:

At the 1 hour reading slight reactions were observed in the cornea and well defined reactions of the coujunctiva (chemosis, redness and discharge) in all the rabbits. The iris were not affected in any of the rabbits. At the 24 hour reading the reactions of conjucntiva had slightly aggravated and the reactions of conjunctiva were unchanged. At the following 48 and 72 hour readings slight to well defined reactions were observed in the cornea and slight to moderate reactions were observed in the conjunctiva. A slight reaction was observed in the iris of one rabbit at the 48 hour readiug. On day 7 slight reactions were observed in the cornea of all the rabbits and slight reactions were observed in the conjunctiva of three rabbits. In one rabbit the conjunctiva appeared normal.
On day 14, the eyes of all 4 rabbits appeared normal.It was therefore concluded that the eye changes induced by the treatment were reversible, and the study was terminated.

Other effects:

conjunctival discharge was seen in all aninals at up to 72 hours.

Table 2: Individual irritation scores

Observation		1h	24h	48h	72h	Mean (24-72h)	7d	14d
Cornea	Opacity	2,1,1,1	2,2,2,2	2,1,2,2	2,1,1,2	1.75	1,1,1,1	0,0,0,0
Iris	Lesion	00,0,0,	0,0,0,0	0,0,0,1	0,0,0,0	0.08	0,0,0,0	0,0,0,0
Conjunctivae	Erythema	3,2,2,3	3,3,3,3	3,2,3,3	3,2,3,3	2.83	1,0,1,1	0,0,0,0
	Chemosis	2,2,2,3	3,2,2,2	3,2,2,2	2,1,2,2	2.08	1,0,1,1	0,0,0,0

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

Based on the results from this in vivo eye irritation study according to OECD Guideline 405, it was concluded that the test substance CTF is irritating to the eyes and therefore should be classified as an eye irritant (Category 2) under CLP Regulation 1272/2008 .

Executive summary:

In a primary eye irritation study performed according to OECD Guideline 405, 0.1 mL of cyclic trimethylolpropane (5-Ethyl-1,3-dioxane-5-methanol, CTF) was instilled as supplied into the conjunctival sac of the left eye of four female albino rabbits. The eyes were not washed. Animals were then examined after 1 hour, 24, 48 and 72 hours and 7 days following instillation and further observed until day 14. Irritation was scored as indicated in OECD Guideline 405. Slight to moderate reactions on cornea and conjunctivae were observed after 24, 48, and 72 hours, while slight reaction persisted up to day 7, and no reactions were seen at 14 days.

Based on the results from this study, it was concluded that the test substance is irritating to the eyes.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There are no reliable studies available for the assessment of the skin irritation and eye irritation endpoints with the target substance, Polyol TD. Therefore, data from suitable read-across partners , 2 -ethylpropane-1,3 -diol (DMP) and 5 -ethyl-1,3 -dioxane-5 -methanol (CTF) was used to assess the skin and eye irritation potential of Polyol TD.

In an in vivo skin irritation study (according to OECD Guideline 404) with CTF (Dyring Jacobsen, 2010), very slight erythema was seen on one rabbit which persisted for the duration of the observation period (24 -72 hours); no signs of erythema or oedema were seen in any of the other three rabbits. It was concluded that CTF should not be classified as irritating to skin under the CLP Regulation 1272/2008. A negative response (87.91% viability) is reported in an EpiSkin in vitro skin irritation assay (according to OECD Guideline 439) performed with DMP (Blackstock, 2010), furthermore supporting the negative skin irritation potential.

The available information therefore demonstrates that the components CTF, DMP and TMP (by read-across from DMP) are not skin irritants and it can be concluded that Polyol TD, which is the reaction mass of 2-ethylpropane-1,3-diol (DMP) and 5-ethyl-1,3-dioxane-5-methanol (CTF) and propylidynetrimethanol (TMP) is not a skin irritant.

 

In a GLP in vivo eye irritation study, conducted according to OECD 405, with rabbits (Dyring Jacobsen, 2010). Slight to moderate reactions were seen at 24, 48, and 72 hours, slight reactions were observed at 7 days, and no reactions were seen at 14 days. It was concluded that the test substance CTF is irritating to the eyes and therefore should be classified as an eye irritant (Category 2) under CLP Regulation 1272/2008 . As CTF is classified as an eye irritant, further testing with the reaction mass of 2-ethylpropane-1,3-diol (DMP) and 5-ethyl-1,3-dioxane-5-methanol (CTF) and propylidynetrimethanol (TMP) or its components is not proposed for reasons of animal welfare and it is assumed that the target substance will also be an eye irritant.

 

Justification for classification or non-classification

Skin irritation/corrosion:

Based on the results available the target substance is not considered as irritant to the skin.Therefore, classification in accordance with CLP Regulation 1272/2008 is not warranted..

.

Eye irritation:

Based on the results available the target substance can be considered as irritant to the eyes. Therefore, classification as Eye Irrit.2, H319 is warranted in accordance with CLP Regulation 1272/2008.