Ethylene diformate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 2) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on structural similarity between the source and target substance, the source substance being a product of the hydrolysis of the target substance (refer to endpoint discussion for further details).
The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII-IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Justification for grouping of substances and read-across

There are no data available on the toxicity to reproduction of Ethylene diformate. In order to fulfil the standard information requirements set out in Annex IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances is 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 physicochemical, toxicological and ecotoxicological properties may be predicted from data for reference substance(s) by interpolation to other substances on the basis of structural similarity, ethane-1,2-diol (ethylene glycol) (CAS 107-21-1), formic acid (CAS 64-18-6) and sodium formate (CAS 141-53-7) are selected as reference substances for assessment of toxicity to reproduction.

The read-across is based on the metabolism of Ethylene diformate, in particular on the fact that the substance undergoes enzymatic ester hydrolysis resulting in the formation of ethylene glycol and formic acid. Sodium formate is the sodium salt of formic acid, anticipated to dissociate into the corresponding ions upon contact with (tissue) water. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Overview of in vitro genetic toxicity

CAS#	Chemical name	Molecular weight	Toxicity to reproduction – fertility	Toxicity to reproduction – (pre-natal) development
629-15-2 (a)	Ethylene diformate	118.09	WoE: RA: CAS 107-21-1 RA: CAS 64-18-6	WoE: RA: CAS 107-21-1 RA: CAS 141-53-7
107-21-1 (b)	Ethane-1,2-diol (Ethylene glycol)	62.07	Experimental result: NOAEL fertility (rat, P/F1/F2) ≥ 1000 mg/kg bw/day (three-generation study)	Experimental result: NOAEL (pre-natal) development (rabbit) ≥ 2000 mg/kg bw/day
64-18-6	Formic acid	46.03	NOAEC effects on reproductive organs (rat, m/f) ≥ 244.7 mg/m³	--
141-53-7	Sodium formate	69.01	--	Experimental result: NOAEL (pre-natal) development (rabbit) ≥ 1000 mg/kg bw/day

(a) The substance subject to registration is indicated in bold font.

(b) Reference (read-across) substances are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

 

Toxicity to reproduction – fertility

CAS 107-21-1

Ethylene glycol was tested in a three-generation reproduction study in rats similarly to OECD 416 and in a dominant lethal mutagenesis study (DePass, 1986).

Groups of 10 male and 20 female Fischer 344 rat were exposed to 40, 200 and 1000 mg/kg bw/day of ethylene glycol in the diet during three generations of reproduction. In the dominant lethal mutagenesis study, the F2 males from the reproduction study were bred to three consecutive lots of untreated females at weekly intervals. Concomitantly, a further group of untreated F2 males that received a single injection of 0.50 mg/kg bw triethylenemelamine (TEM) were bred similarly to serve as a positive control group. Dominant lethal effects in the triethylenemelamine group confirmed the susceptibility of the rats to a known mutagen. Two concurrent control groups receiving the untreated diet were included in the testing.

Examination of the parental animals revealed no effects on the reproductive performance of the parental generations. In addition, no effects on clinical signs, mortality, body weight, organ weights or during gross necropsy and histopathological examination of the parental animals were observed. Slight apparent increases in the dominant lethal mutation index, observed during the Week 2 mating for the high-dose (1000 mg/kg bw/day) group and during the Week 3 mating for the low-dose (40 mg/kg bw/day) group, were probably random occurrences unrelated to treatment. This interpretation is consistent with the absence of a dose-response relationship and the fact that a negative index of similar magnitude was observed for the low-dose group in the Week 2 mating. When compared to the combined control groups, significant decreases were observed as a result of TEM treatment for the number of females with implants, the total number of implants and the number of live implants. In the offspring, no changes on viability, clinical signs, body weight, fertility indices and organ weights were observed. In addition, during gross pathology and histopathological examination of F2 and F3 animals no treatment-related effects were apparent. The fertility index for male and female offspring, the days from first mating to parturition, the gestation index and the fraction of pregnancies that resulted in litters with live pups were not affected by treatment in any dose group.

Thus, under the conditions of the study, ethylene glycol had no effect on reproductive performance and the NOAEL for reproduction toxicity of the parental and the F1 and F2 generation is considered to be ≥ 1000 mg/kg bw/day (m, f).

CAS 64-18-6

In the subchronic inhalation toxicity test with formic acid, possible effects on reproductive tissue were evaluated as well (National Toxicology Program, 1992). The study was performed similarly to OECD guideline 413 and in compliance with GLP. Groups of 10 Fischer 344 rats were exposed whole body to 8 – 128 ppm formic acid (15.3 – 244.7 mg/m³), 6 h/day, 5 days/week, for 13 weeks.

In the study, no systemic adverse effects were observed up to the highest dose tested. Additional examinations on the reproductive tissue showed no effects on sperm motility, density, or testicular or epididymal weights. Furthermore, no changes were seen in the length of the estrous cycle.

Therefore the NOAEC for effects on reproductive organs is estimated to be ≥ 244.7 mg/m³

Conclusions for toxicity to reproduction – fertility

There are no data available on the toxicity to reproduction (fertility) of Ethylene diformate.

Ethylene diformate is anticipated to undergo enzymatic ester hydrolysis within the body resulting in the formation of ethylene glycol and formic acid, as indicated by an in vitro hydrolysis test (Butler, 2013). Thus, the available data on the hydrolysis products was used for assessment by means of read-across applying an analogue approach.

Ethylene glycol has been tested for toxicity to reproduction in a three-generation study also including a dominant lethal mutagenesis study. No effects were observed in any of the reproductive parameters examined as well as in the dominant lethal mutagenesis study up to the highest dose level tested. Therefore, the NOAEL for reproduction was ≥ 1000 mg/kg bw/day in the P, F1 and F2 generations.

In a subchronic inhalation toxicity study with formic acid, no effects on reproductive organs were observed up to the highest concentration tested. Thus, the NOAEC for effects on reproductive organs was ≥ 244.7 mg/m³.

Based on read-across from the anticipated products of ester hydrolysis, the available data do not provide any evidence for toxic effects to reproduction after exposure to Ethylene diformate.

Short description of key information:
Based on read-across from ethylene glycol (CAS No. 107-21-1) and formic acid (CAS No. 64-18-6), and in a weight of evidence approach, no hazard was identified.
The available long-term study on toxicity to reproduction resulted in a NOAEL ≥ 1000 mg/kg bw/day.

Justification for selection of Effect on fertility via oral route:
Hazard assessment is conducted by means of read-across from structural analogues/surrogates. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between source and target substance and overall assessment of quality, duration and dose descriptor level (refer to the endpoint discussion for further details).

Effects on developmental toxicity

Description of key information

Based on read-across from ethylene glycol (CAS No. 107-21-1) and sodium formate (CAS No. 141-53-7), and in a weight of evidence approach, no hazard was identified.
All available studies on developmental toxicity and teratogenicity resulted in NOAELs ≥ 1000 mg/kg bw/day.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises adequate and reliable study (Klimisch score 2) from reference substances with similar structure and intrinsic properties. Read-across is justified based on structural similarity between the source and target substances, the source substances being the products of the hydrolysis of the target substance (refer to endpoint discussion for further details).
The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII-IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Justification for grouping of substances and read-across

There are no data available on the toxicity to reproduction of Ethylene diformate. In order to fulfil the standard information requirements set out in Annex IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances is 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 physicochemical, toxicological and ecotoxicological properties may be predicted from data for reference substance(s) by interpolation to other substances on the basis of structural similarity, ethane-1,2-diol (ethylene glycol) (CAS 107-21-1), formic acid (CAS 64-18-6) and sodium formate (CAS 141-53-7) are selected as reference substances for assessment of toxicity to reproduction.

The read-across is based on the metabolism of Ethylene diformate, in particular on the fact that the substance undergoes enzymatic ester hydrolysis resulting in the formation of ethylene glycol and formic acid. Sodium formate is the sodium salt of formic acid, anticipated to dissociate into the corresponding ions upon contact with (tissue) water. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Overview of in vitro genetic toxicity

CAS#	Chemical name	Molecular weight	Toxicity to reproduction – fertility	Toxicity to reproduction – (pre-natal) development
629-15-2 (a)	Ethylene diformate	118.09	WoE: RA: CAS 107-21-1 RA: CAS 64-18-6	WoE: RA: CAS 107-21-1 RA: CAS 141-53-7
107-21-1 (b)	Ethane-1,2-diol (Ethylene glycol)	62.07	Experimental result: NOAEL fertility (rat, P/F1/F2) ≥ 1000 mg/kg bw/day (three-generation study)	Experimental result: NOAEL (pre-natal) development (rabbit) ≥ 2000 mg/kg bw/day
64-18-6	Formic acid	46.03	NOAEC effects on reproductive organs (rat, m/f) ≥ 244.7 mg/m³	--
141-53-7	Sodium formate	69.01	--	Experimental result: NOAEL (pre-natal) development (rabbit) ≥ 1000 mg/kg bw/day

(a) The substance subject to registration is indicated in bold font.

(b) Reference (read-across) substances are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

Toxicity to reproduction – (pre-natal) development

CAS 107-21-1

A study investigating the developmental toxicity of ethylene glycol in rabbits is available. Ethylene glycol was tested in an oral prenatal developmental toxicity study similar to OECD 414 (Tyl, 1993).

Groups of 11-12 female New Zealand white rabbits were administered ethylene glycol by gavage on Gestational Days (GD) 6 through 19 at doses of 100, 500, 1000 and 2000 mg/kg bw/day. Concurrent negative control groups receiving the vehicle water alone were included. At the high-dose group, maternal toxicity and an increase in early deliveries and one abortion was observed. The pregnancy rate was slightly lower (81.8 %) in this group as well. Maternal body weight changes and water consumption were equivalent across all groups for all intervals evaluated. No treatment-related clinical signs of toxicity were observed up to 1000 mg/kg bw/day. Maternal absolute kidney weight was slightly increased and showed histological lesions at 2000 mg/kg bw/day. The lesions were limited to the cortical renal tubules and included intraluminal crystals, epithelial necrosis and tubular dilatation and degeneration. The cause of death in these animals was determined to be renal failure. No significant effects of treatment on corrected maternal gestational weight change, gravid uterine weight, liver weight or kidney weight at any dose were observed. There were no treatment-related effects on any gestational parameters, including prenatal mortality, or for prenatal toxicity and no treatment-related alterations in incidence of malformations, pooled as external, visceral or skeletal, or as total malformations or variations. Thus, under the condition of the study, the NOAEL for maternal toxicity in rabbits was 1000 mg/kg bw/day based on renal injury in the high-dose animals. No indications of embryotoxicity or teratogenic effects were observed resulting in a NOAEL for developmental toxicity ≥ 2000 mg/kg bw/day in rabbits (m, f).

CAS 141-53-7

A study investigating the developmental toxicity of sodium formate in rabbits is available (Schneider, 2008). In general, formate salts are used as test material in studies requiring repeated dose administration, due to the corrosivity of formic acid. Thus, formate salt was used as structurally related substance. Sodium formate was tested in an oral prenatal developmental toxicity study similarly to OECD 414. Groups of 25 female Himalayan rabbits were administered sodium formate by gavage on Gestational Days (GD) 6-28 at doses of 100, 300 and 1000 mg/kg bw/day. Concurrent negative control groups receiving the vehicle water alone were included.

No clinical signs of toxicity and no treatment-related mortalities were observed. Food consumption and body weights showed no substance-related changes. In addition, no findings during gross necropsy were apparent in maternal animals. There were no treatment-related effects in developmental parameters. Foetal weight at birth, sex distribution, placenta weight, pre- and post-implantation loss was not affected. There were no unusual or increased incidences of external, soft tissue or skeletal malformations attributable to the treatment.

Thus, under the condition of the study, the NOAEL for maternal toxicity in rabbits was ≥ 1000 mg/kg bw/day. No indications of embryotoxicity or teratogenic effects were observed resulting in a NOAEL for developmental toxicity ≥ 1000 mg/kg bw/day in rabbits (m,f).

Conclusions for toxicity to reproduction – (pre-natal) development

There are no data available on the toxicity to reproduction ((pre-natal) development) of Ethylene diformate.

Ethylene diformate is anticipated to undergo enzymatic ester hydrolysis within the body resulting in the formation of ethylene glycol and formic acid, as indicated by an in vitro hydrolysis test (Butler, 2013). Thus, the available data on the hydrolysis products was used for assessment by means of read-across applying an analogue approach.

Ethylene glycol has been tested in a pre-natal developmental toxicity study in rabbits. Maternal toxicity effects were observed at the highest dose of 2000 mg/kg bw/day. However, no embryotoxic or teratogenic effects were observed up to and including this dose level. Therefore, the NOAEL for maternal toxicity was 1000 mg/kg bw/day, and the NOAEL for pre-natal development was ≥ 2000 mg/kg bw/day

The sodium salt of formic acid has also been tested in a pre-natal development study in rabbits. No effects were observed in any of the parameters examined. Therefore, the NOAEL values for maternal toxicity and pre-natal development were both ≥ 1000 mg/kg bw/day.

Based on read-across from the anticipated products of ester hydrolysis, the available data do not provide any evidence for toxic effects on intrauterine development after exposure to Ethylene diformate.

Justification for selection of Effect on developmental toxicity: via oral route:
Hazard assessment is conducted by means of read-across from structural analogues/surrogates. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between source and target substances and overall assessment of quality, duration and dose descriptor level (refer to the endpoint discussion for further details).

Justification for classification or non-classification

Based on read-across following an analogue approach, the available data on the reproductive toxicity of Ethylene diformate do not meet the classification criteria according to Regulation (EC) 1272/2008 or according to Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.