1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates

Endpoint summary

Description of key information

Acute toxicity: Oral LD50 (rat, m/f): > 2000 mg/kg bw (WoE, analogue approach)
Acute toxicity: Inhalation LC50 (rat, m/f): > 5.0 mg/L air (WoE, analogue approach)
Acute toxicity: Dermal LD50 (rat, m/f): > 2000 mg/kg bw (WoE, analogue approach)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 2) studies from reference substances with similar structure and intrinsic properties. Read-across is justified based on common origin, common precursors and breakdown products of hydrolysis and consistend trends in environmental fate, ecotoxicological and toxicological profile (refer to endpoint discussion for further details).
Taken together, the information from these independent sources is consistent and provides sufficient weight of evidence for hazard assessment leading to an endpoint conclusion in accordance with Annex XI, 1.2, of Regulation (EC) No 1907/2006. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 2) studies from reference substances with similar structure and intrinsic properties. Read-across is justified based on common origin, common precursors and breakdown products of hydrolysis and consistent trends in environmental fate, ecotoxicological and toxicological profile (refer to endpoint discussion for further details).
Taken together, the information from these independent sources is consistent and provides sufficient weight of evidence for hazard assessment leading to an endpoint conclusion in accordance with Annex XI, 1.2, of Regulation (EC) No 1907/2006. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 2) studies from reference substances with similar structure and intrinsic properties. Read-across is justified based on common origin, common precursors and breakdown products of hydrolysis and consistent trends in environmental fate, ecotoxicological and toxicological profile (refer to endpoint discussion for further details).
Taken together, the information from these independent sources is consistent and provides sufficient weight of evidence for hazard assessment leading to an endpoint conclusion in accordance with Annex XI, 1.2, of Regulation (EC) No 1907/2006. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Additional information

Justification for grouping of substances and read-across

There are no data available for the acute inhalation and dermal toxicity of 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates (CAS 85711-80-4). In order to fulfil the standard information requirements set out in Annex VIII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances was conducted.

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 whereby substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity, the substances Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5), Pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids (CAS 68424-31-7), 3,5,5-trimethylhexanoic acid mixed tetraesters with PE and valeric acid (CAS 131459-39-7), and 2,2-dimethyl-1,3-propanediyl dioleate (CAS 42222-50-4) are selected as source for risk assessment.

Acute toxicity: oral

In addition to the acute oral toxicity study performed with the target substance 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates (CAS 85711-80-4), a reliable study available for the structural analogue Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5), was considered for hazard assessment.

CAS 85711-80-4

An acute oral toxicity study with 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates is available (Bouffechoux, 1995). No information is given on the guideline followed or on GLP compliance. Five female Swiss mice were orally exposed to the test item via gavage at a limit dose of 2000 mg/kg bw. During the 14-day observation period the animals were subjected to clinical observations and weighing. No necropsy was performed after terminal sacrifice. No mortality occurred and no clinical signs of toxicity were observed during the study period. No effects on body weights were noted. The oral LD50 value in mice was determined >2000 mg/kg bw.

CAS 68855-18-5

An acute oral toxicity study with Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5) was performed according to OECD Guideline 401 (standard acute method) and GLP (Doyle, 1996). In a preliminary study, the test item was administered by gavage to two Alderley Park albino rats (Alpk: APfSD) per sex at 2000 mg/kg bw (limit test). Five further animals per sex were then treated with the same dose for the main study. The animals were subjected to daily observations and determinations of body weights on test Days -1 (prior to fasting), 1, 3, between Days 4 and 6, and on Day 8 and 15. Macroscopic examination was performed after terminal sacrifice. No mortality occurred and no clinical signs of toxicity were observed during the study period. No effects on body weights were noted and necropsy revealed no treatment-related findings. The oral LD50 value in rats was determined >2000 mg/kg bw.

Acute toxicity: inhalation

Since no studies are available investigating the acute inhalation toxicity of 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 read-across to the structurally related analogue substances Pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids (CAS 68424-31-7) and Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5) was conducted.

CAS 68424-31-7

An acute inhalation toxicity study (limit test) was performed with Pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids (CAS# 68424-31-7) according to OECD guideline 403 (Parr-Dobrzanski, 1994). Five rats per sex were exposed (nose only) to an aerosol of the test material with an analytical concentration of 5.10 mg/L air (nominal concentration was 5.0 mg/L) for an exposure duration of four hours. No mortality occurred during the 14 day study period. Some clinical signs were noticed, which consisted of hunched position, chromodacryorrhea, piloerection, staining around nose and wet fur. These signs however occurred during or just after exposure and were clearly consistent with the use of restraint for exposure. No effect on body weight was noted. Finally necropsy and histopathological examination revealed no substance-related findings. Thus, the Fatty acids, C5-10, esters with pentaerythritol (CAS# 68424-31-7) in male and female rats was found to be greater than 5.1 mg/L air.

CAS 68855-18-5

An acute inhalation toxicity study was performed with Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5) according to OECD Guideline 436 (acute toxic class method) under GLP conditions. Three RccHanTM:WIST rats per sex were exposed for 4 h to 5.22 mg/L (mean achieved concentration) test substance aerosol by nose only inhalation (Griffiths, 2012). The test concentration was chosen based on the outcome of a preliminary test with two rats at a dose of 2.14 mg/L. In the main study, the animals were subjected to daily observations for clinical signs, and twice daily for morbidity and mortality. Body weights were determined prior to treatment and afterwards on test Days 1, 3, 7, and 14. After terminal sacrifice the animals were submitted to full external and internal observation. Detailed macroscopic examination of the respiratory tract was performed to determine signs of irritancy or local toxicity. No mortality occurred throughout the study period. Signs of hunched posture and piloerection were commonly seen in animals for short period on removal from the chamber following 4-h inhalation studies. Wet fur was commonly recorded both during and for a short period after exposure. These observations were considered to be associated with the restraint procedure and, in isolation, were not indicative of toxicity. In addition, an increased respiratory rate was noted in all animals. On removal from the chamber and 1 h post-exposure, all animals exhibited increased respiratory rate and ataxia. One day after exposure, all animals still showed increased respiratory rate and also hunched posture as well as occasional instances of piloerection. All animals recovered to appear normal from Days 5 to 8 post-exposure. All animals showed the expected body weight gain during the study, except for one female which not gained weight during the final week of the 14-day observation period. In addition, one male exhibited a slight loss in body weight on the first day of exposure. Necropsy revealed no treatment-related findings. The inhalation LC50 value in rats was determined >5.22 mg/L.

Acute toxicology: dermal

Since no studies are available investigating the acute dermal toxicity of 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates (CAS 85711-80-4), in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 read-across to the structurally related analogue substance 3,5,5-trimethylhexanoic acid mixed tetraesters with PE and valeric acid (CAS 131459-39-7) and 2,2-dimethyl-1,3-propanediyl dioleate (CAS 42222-50-4) was conducted.

CAS 131459-39-7

The acute dermal toxicity potential of 3,5,5-trimethylhexanoic acid mixed tetraesters with pentaerythritol and valeric acid (CAS 131459-39-7) was investigated in a limit test performed according to OECD guideline 402 (Allen, 1999) under GLP conditions. The back and flanks regions of five male and female Sprague-Dawley rats were treated with 2000 mg/kg bw test material under semiocclusive conditions. 24 h after the dosing the treated area of skin was cleaned with distilled water and cotton wool. No mortality occurred and no clinical signs of toxicity were observed in any of the animals during the 14-day observation period. Necropsy and histopathological examination revealed no substance-related findings. The test substance had no effect on body weight.

Thus, the dermal LD50 after treatment with 3,5,5-trimethylhexanoic acid mixed tetraesters with pentaerythritol and valeric acid in male and female rats was found to be greater than 2000 mg/kg bw.

CAS 42222-50-4

An acute dermal toxicity study was performed with 2,2-dimethyl-1,3-propanediyl dioleate (CAS 42222-50-4) according to OECD Guideline 402 (standard acute method, limit test) and GLP (Haferkorn, 2012). Five WiCD/Crl:CD(SD) rats per sex were dosed 2000 mg/kg bodyweight for 24 hours on the back skin under occlusive conditions. The animals were subjected to daily observations and body weights were determined prior to test material administration and weekly thereafter. Skin reactions (erythema and oedema) were observed and scored 24, 48, 72 and 96 h after test substance application (Days 2-5), as well as on Days 8-12 during the 14-day observation period. Macroscopic examinations were performed after terminal sacrifice. No mortality occurred and no clinical signs of systemic toxicity were observed during the study period. No skin erythema and edema (scores 0) were observed 24, 48 and 72 h after substance application and up to the end of the 14-day observation period. No effects on body weights were noted and necropsy revealed no treatment-related findings. The dermal LD50 value in rats was determined >2000 mg/kg bw.

In addition, only a low dermal absorption potential is predicted for 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates (CAS 85711-80-4) based on QSAR analysis. Calculated dermal absorption values in the range of 8.40*10E-7 to 5.84*E-5 mg/cm²/event (low) predict a low potential for dermal absorption for 1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates (Dermwin v.2.01, 2011).

 

Conclusion for acute toxicity

In summary, two studies conducted with the target substance and the structurally similar analogue substance Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5)are available for acute oral toxicity. Both studies resulted in oral LD50 values greater than 2000 mg/kg bw. For acute inhalation toxicity, two studies are available for the substances Pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids (CAS 68424-31-7) and Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS 68855-18-5). From these studies, a LC50 value for male and female rats greater than 5.0 mg/L air was evaluated. Furthermore, two acute dermal toxicity studies conducted with the analogue substances 3,5,5-trimethylhexanoic acid mixed tetraesters with pentaerythritol and valeric acid (CAS 131459-39-7) and 2,2-dimethyl-1,3-propanediyl dioleate (CAS 42222-50-4) showed no effects at the limit dose 2000 mg/kg bw.

Thus, the available data indicate a very low level of acute toxicity for the tested substances and thus, no hazard for acute oral, inhalation, and dermal toxicity was identified.

Justification for selection of acute toxicity – oral endpoint
Hazard assessment is conducted means of read-across based on structural analogues. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between source and target substances and overall quality assessment (refer to the endpoint discussion for further details).

Justification for selection of acute toxicity – inhalation endpoint
Hazard assessment is conducted means of read-across based on structural analogues. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between source and target substances and overall quality assessment (refer to the endpoint discussion for further details).

Justification for selection of acute toxicity – dermal endpoint
Hazard assessment is conducted means of read-across based on structural analogues. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between source and target substances and overall quality assessment (refer to the endpoint discussion for further details).

Justification for classification or non-classification

Based on the information received for the test substance and read-across from structurally similar substances, the available data on acute oral, inhalation and dermal toxicity do not meet the classification criteria according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.