2-ethylhexanoic acid, iron salt

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

No toxicity data on adverse effects on reproduction with 2-ethylhexanoic acid, iron salt are available, thus the reproductive toxicity will be addressed with existing data on the individual assessment entities iron and 2-ethylhexanoic acid. Since the assessment entity 2-ethylhexanoic acid is legally classified for reproductive toxicity (Repro cat. 2, H361d, Index No. 607-230-00-6), 2-ethylhexanoic acid, iron salt is self-classified for Reproduction toxicity Category 2, with the Hazard statement H361d (suspected of damaging the unborn child). Both assessment entities have not shown to impair fertility in a number of animal studies.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Iron

Animal data

In a repeated dose toxicity study with reproductive and developmental screening (according to OECD 422 and under GLP), iron(II)sulfate was administered to rats at doses of 30, 100, 300 and 1000 mg/kg bw/day via gavage (Pharmaceutical and Food Safety Bureau 2002).

General observation revealed salivation in males and females in the ≥300 mg/kg bw/day groups. This was transient and only observed immediately after administration, and there were no neurological symptoms such as convulsion or morphological changes to the salivary glands, and so the salivation was attributed to irritation by the test substance, and was not deemed to be a symptom of toxicity.

With regard to the reproduction/development of the parent animals, no histopathological changes were observed in the testes, epididymis, seminal vesicles, prostate, ovaries, uterus, vagina or mammary glands at any dose level. Moreover, no changes due to administration were observed in the number of oestrus, copulation index, number of days required for copulation, conception index, gestation index, nursing, lactation, number of corpora lutea, number of implantations, implantation index or gestation period.

In the pups, no changes due to administration were observed in the total number of pups born, number of stillbirths, number of pups on lactation day 0, sex ratio on lactation day 0, delivery index, birth index, or live birth index. No changes due to administration were observed in the general condition of the pups. No changes due to administration were observed in the number of live pups on lactation day 4, sex ratio of the live pups on lactation day 4, or viability on lactation day 4. External observation revealed no changes due to administration. No changes due to administration were observed in the body weights. The necropsies of the pups revealed no changes due to administration.

In conclusion, a NOAEL for reproductive toxicity of 1000 mg/kg/day (equivalent to 201 mg Fe/kg bw/day) was concluded for the male and female rats due to the absence of any relevant toxicological effects. Also, a No Observed Adverse Effect Level (NOAEL) of 1000 mg/kg/day (equivalent to 201 mg Fe/kg bw/day) was concluded for the offspring (F1 generation) based on the absence of any relevant toxicological effect.

 

The National Institute of Environmental Research conducted a combined repeated dose toxicity study with reproductive and developmental toxicity screening in rats. Rats were exposed to ferrous chloridefor 42-54 days (males: 42 days, females: 42-54 days). Animals were divided into four treatment groups exposed to 0, 125, 250 and 500 mg/kg bw day. This study found no indication of any reproductive or developmental toxicity in parent animals and offspring at the maximum tested dose of 500 mg/kg bw/day (equivalent to 220 mg Fe /kg bw/day). Therefore, the NOAEL for reproductive toxicity was 500 mg/kg bw/day. The original reference could not be obtained and this study entry is based on an available study summary, but the study was approved by the OECD procedure on Mutual Acceptance of Data (MAD).

 

Human data

There is no evidence of any reprotoxic for (non-haem) iron compounds. Iron is abundantly available in the environment and in food, and is extensively distributed throughout the human body, which is contradictory to allegation of reprotoxic potential.

According to the European Food Safety Authority the EU population the reference intake is about 18–72 mg iron per day for the general population. During pregnancy, 450 mg Fe is needed to allow increased erythropoiesis, while 270-300 mg and 50-90 mg are transferred to the foetus and placenta, which gives a total extra demand of 770-840 mg. This demand corresponds to approx. 3 mg Fe/day and will be provided by an intake of 30 mg Fe/day and is the rationale for the recommended higher iron intake in pregnancy (FNB, 2001; Arbeitsgruppe “Referenzwerte für Nährstoffzufuhr, 2000).

Three main factors that affect iron balance are absorption (intake and bioavailability of iron), losses, and stored amount. The interrelationship among these factors has recently been described in mathematical terms, making it possible to predict, for example, the amount of stored iron when iron losses and bioavailability of dietary iron are known (Hallberg L et al., 1998). In states of increased iron requirement or decreased bioavailability, the regulatory capacity to prevent iron deficiency is limited (Hallberg L et al., 1995). However, the regulatory capacity seems to be extremely good in preventing iron overload in a state of increased dietary iron intake or bioavailability (Hallberg L et al., 1998).

Reprotoxic potential of the abundantly available essential element iron are grossly implausible and can be safely excluded. Therefore, further testing should not be considered, inter alia for reasons of animal welfare. In conclusion, conduct of studies for reproductive toxicity on iron is considered to be scientifically unjustified (in accordance with regulation (EC) 1907/2006, Annex XI, Section 1.1.3 and 1.2).

 

2-ethylhexanoic acid

2-Ethylhexanoic acid was administered via drinking water to an unspecified number of male and female rats at 0, 100, 300, or 600 mg/kg–bw/day. There were no deaths. The relative epididymal weights in high-dose males were significantly increased, but no histologic changes were noted. A slight, but not statistically significant, increase in the number of abnormal sperm was noted in the highest two dose groups; however, the incidence per animal was not provided. Treated groups required more time to successfully complete mating, and the mean litter size in high-dose pregnant females was significantly reduced. The mean pup weights in the high-dose group were significantly lower on postnatal day 7 and 14.

Physical development of the eyes, teeth and hair appeared to be slightly later in the pups from the high-dose groups; the significance of this finding is unclear since no data were presented on the length of gestation in treated and control dams. The high-dose of 600 mg/kg–bw/day significantly reduced overall water consumption and body weights in female animals. The NOAEL for reproductive effects in parental animals was 300 mg/kg-bw/day; this effect occurred in the presence of maternal toxicity. The NOAEL for F1 offspring was 100 mg/kg-bw/day.

 

The developmental toxicity of 2-ethylhexanoic acid has been investigated in a standard study in rabbits [USEPA TSCA Health Effects Testing Guidelines CFR 798.4900 (similar to OECD TG 414)]. 2-Ethylhexanoic acid was administered (15/dose) via gavage at 0, 25, 125, or 250 mg/kg-bw/day on days 6 through 18 of gestation. One middose and one high-dose animal died on test. In addition, one mid-dose animal aborted prior to term. High-dose dams experienced hypoactivity, ataxia, and gasping. Body weights and food consumption of animals in this group were reduced. The NOAEL for maternal animals was 25 mg/kg–bw/day and the NOAEL for offspring was 250 mg/kg-bw/day (the highest dose tested). In a guideline study [OECD TG 414] 2-ethylhexanoic acid was administered via drinking water to an unspecified number of animals at 0, 100, 300, or 600 mg/kg-bw/day, for days 6-19 of gestation. No death was observed. Mean foetal weight per litter and mean placental weights were significantly reduced in the mid- and high-dose groups. Clubfoot was the only skeletal malformation; changes in skeletal variations were also noted (wavy ribs, reduced cranial ossification, and twisted hind legs). Corrected maternal body weights at termination and weight gains of high-dose females were significantly reduced. The NOAEL for maternal animals was 300 mg/kg-bw/day; the NOAEL for offspring was 100 mg/kg-bw/day. Based on these results, 2-ethylhexanoic acid is not likely to cause effects on fertility but is likely to be a developmental toxicant. The developmental toxicity of 2-ethylhexanoic acid is at least partially related to disruption of Zn metabolism and distribution in the mother, and that higher zinc levels in the mothers leads to lower developmental toxicity in offspring.

Classificiation according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 for Reproduction toxicity is required: Hazard Category 2, with the Hazard statement H361d (suspected of damaging the unborn child) (Annex VI).

 

2-ethylhexanoic acid, iron salt

Since no reproductive toxicity study is available for 2-ethylhexanoic acid, iron salt, information on the individual moieties iron and 2-ethylhexanoic acid will be used for the hazard assessment and, when applicable, for the risk characterisation. Both assessment entities do not impair fertility in animal studies available for assessment. For further information on the toxicity of the individual moieties, please refer to the relevant sections in the IUCLID and CSR.

Effects on developmental toxicity

Description of key information

No toxicity data on adverse effects on reproduction with 2-ethylhexanoic acid, iron salt are available, thus the reproductive toxicity will be addressed with existing data on the individual assessment entities iron and 2-ethylhexanoic acid. Since the assessment entity 2-ethylhexanoic acid is legally classified for reproductive toxicity (Repro cat. 2, H361d, Index No. 607-230-00-6), 2-ethylhexanoic acid, iron salt is self-classified for Reproduction toxicity Category 2, with the Hazard statement H361d (suspected of damaging the unborn child). Both assessment entities have not shown to impair fertility in a number of animal studies.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

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

Iron

Animal data

In a repeated dose toxicity study with reproductive and developmental screening (according to OECD 422 and under GLP), iron(II)sulfate was administered to rats at doses of 30, 100, 300 and 1000 mg/kg bw/day via gavage (Pharmaceutical and Food Safety Bureau 2002).

General observation revealed salivation in males and females in the ≥300 mg/kg bw/day groups. This was transient and only observed immediately after administration, and there were no neurological symptoms such as convulsion or morphological changes to the salivary glands, and so the salivation was attributed to irritation by the test substance, and was not deemed to be a symptom of toxicity.

With regard to the reproduction/development of the parent animals, no histopathological changes were observed in the testes, epididymis, seminal vesicles, prostate, ovaries, uterus, vagina or mammary glands at any dose level. Moreover, no changes due to administration were observed in the number of oestrus, copulation index, number of days required for copulation, conception index, gestation index, nursing, lactation, number of corpora lutea, number of implantations, implantation index or gestation period.

In the pups, no changes due to administration were observed in the total number of pups born, number of stillbirths, number of pups on lactation day 0, sex ratio on lactation day 0, delivery index, birth index, or live birth index. No changes due to administration were observed in the general condition of the pups. No changes due to administration were observed in the number of live pups on lactation day 4, sex ratio of the live pups on lactation day 4, or viability on lactation day 4. External observation revealed no changes due to administration. No changes due to administration were observed in the body weights. The necropsies of the pups revealed no changes due to administration.

In conclusion, a NOAEL for reproductive toxicity of 1000 mg/kg/day (equivalent to 201 mg Fe/kg bw/day) was concluded for the male and female rats due to the absence of any relevant toxicological effects. Also, a No Observed Adverse Effect Level (NOAEL) of 1000 mg/kg/day (equivalent to 201 mg Fe/kg bw/day) was concluded for the offspring (F1 generation) based on the absence of any relevant toxicological effect.

 

The National Institute of Environmental Research conducted a combined repeated dose toxicity study with reproductive and developmental toxicity screening in rats. Rats were exposed to ferrous chloridefor 42-54 days (males: 42 days, females: 42-54 days). Animals were divided into four treatment groups exposed to 0, 125, 250 and 500 mg/kg bw day. This study found no indication of any reproductive or developmental toxicity in parent animals and offspring at the maximum tested dose of 500 mg/kg bw/day (equivalent to 220 mg Fe /kg bw/day). Therefore, the NOAEL for reproductive toxicity was 500 mg/kg bw/day. The original reference could not be obtained and this study entry is based on an available study summary, but the study was approved by the OECD procedure on Mutual Acceptance of Data (MAD).

 

Human data

There is no evidence of any reprotoxic for (non-haem) iron compounds. Iron is abundantly available in the environment and in food, and is extensively distributed throughout the human body, which is contradictory to allegation of reprotoxic potential.

According to the European Food Safety Authority the EU population the reference intake is about 18–72 mg iron per day for the general population. During pregnancy, 450 mg Fe is needed to allow increased erythropoiesis, while 270-300 mg and 50-90 mg are transferred to the foetus and placenta, which gives a total extra demand of 770-840 mg. This demand corresponds to approx. 3 mg Fe/day and will be provided by an intake of 30 mg Fe/day and is the rationale for the recommended higher iron intake in pregnancy (FNB, 2001; Arbeitsgruppe “Referenzwerte für Nährstoffzufuhr, 2000).

Three main factors that affect iron balance are absorption (intake and bioavailability of iron), losses, and stored amount. The interrelationship among these factors has recently been described in mathematical terms, making it possible to predict, for example, the amount of stored iron when iron losses and bioavailability of dietary iron are known (Hallberg L et al., 1998). In states of increased iron requirement or decreased bioavailability, the regulatory capacity to prevent iron deficiency is limited (Hallberg L et al., 1995). However, the regulatory capacity seems to be extremely good in preventing iron overload in a state of increased dietary iron intake or bioavailability (Hallberg L et al., 1998).

Reprotoxic potential of the abundantly available essential element iron are grossly implausible and can be safely excluded. Therefore, further testing should not be considered, inter alia for reasons of animal welfare. In conclusion, conduct of studies for reproductive toxicity on iron is considered to be scientifically unjustified (in accordance with regulation (EC) 1907/2006, Annex XI, Section 1.1.3 and 1.2).

 

2-ethylhexanoic acid

2-Ethylhexanoic acid was administered via drinking water to an unspecified number of male and female rats at 0, 100, 300, or 600 mg/kg–bw/day. There were no deaths. The relative epididymal weights in high-dose males were significantly increased, but no histologic changes were noted. A slight, but not statistically significant, increase in the number of abnormal sperm was noted in the highest two dose groups; however, the incidence per animal was not provided. Treated groups required more time to successfully complete mating, and the mean litter size in high-dose pregnant females was significantly reduced. The mean pup weights in the high-dose group were significantly lower on postnatal day 7 and 14.

Physical development of the eyes, teeth and hair appeared to be slightly later in the pups from the high-dose groups; the significance of this finding is unclear since no data were presented on the length of gestation in treated and control dams. The high-dose of 600 mg/kg–bw/day significantly reduced overall water consumption and body weights in female animals. The NOAEL for reproductive effects in parental animals was 300 mg/kg-bw/day; this effect occurred in the presence of maternal toxicity. The NOAEL for F1 offspring was 100 mg/kg-bw/day.

 

The developmental toxicity of 2-ethylhexanoic acid has been investigated in a standard study in rabbits [USEPA TSCA Health Effects Testing Guidelines CFR 798.4900 (similar to OECD TG 414)]. 2-Ethylhexanoic acid was administered (15/dose) via gavage at 0, 25, 125, or 250 mg/kg-bw/day on days 6 through 18 of gestation. One middose and one high-dose animal died on test. In addition, one mid-dose animal aborted prior to term. High-dose dams experienced hypoactivity, ataxia, and gasping. Body weights and food consumption of animals in this group were reduced. The NOAEL for maternal animals was 25 mg/kg–bw/day and the NOAEL for offspring was 250 mg/kg-bw/day (the highest dose tested). In a guideline study [OECD TG 414] 2-ethylhexanoic acid was administered via drinking water to an unspecified number of animals at 0, 100, 300, or 600 mg/kg-bw/day, for days 6-19 of gestation. No death was observed. Mean foetal weight per litter and mean placental weights were significantly reduced in the mid- and high-dose groups. Clubfoot was the only skeletal malformation; changes in skeletal variations were also noted (wavy ribs, reduced cranial ossification, and twisted hind legs). Corrected maternal body weights at termination and weight gains of high-dose females were significantly reduced. The NOAEL for maternal animals was 300 mg/kg-bw/day; the NOAEL for offspring was 100 mg/kg-bw/day. Based on these results, 2-ethylhexanoic acid is not likely to cause effects on fertility but is likely to be a developmental toxicant. The developmental toxicity of 2-ethylhexanoic acid is at least partially related to disruption of Zn metabolism and distribution in the mother, and that higher zinc levels in the mothers leads to lower developmental toxicity in offspring.

Classificiation according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008 for Reproduction toxicity is required: Hazard Category 2, with the Hazard statement H361d (suspected of damaging the unborn child) (Annex VI).

2-ethylhexanoic acid, iron salt

Since no reproductive toxicity study is available for 2-ethylhexanoic acid, iron salt, information on the individual moieties iron and 2-ethylhexanoic acid will be used for the hazard assessment and, when applicable, for the risk characterisation. Several studies with rats have demonstrated developmental toxicity in response to oral exposure to 2-ethylhexanoic acid. Adverse foetal effects included reduced body weight, and skeletal malformations and variations. The NOAEL was determined to be 100 mg/kg bw/day. Mechanistic studies indicated that the developmental toxicity of 2-ethylhexanoic acid is at least partially related to disruption of zinc metabolism and distribution in the mother. Developmental effects in the one-generation reproduction study occurred at the same levels, also with a NOAEL of 100 mg/kg bw/day.

Justification for classification or non-classification

No toxicity data on adverse effects on reproduction with 2-ethylhexanoic acid, iron salt are available, thus the reproductive toxicity will be addressed with existing data on the individual moieties iron and 2-ethylhexanoate. Since the moiety 2-ethylhexanoic acid of 2-ethylhexanoic acid, iron salt carries a legal classification for reproductive toxicity (Repro cat. 2, H361d, Index No. 607-230-00-6), 2-ethylhexanoic acid, iron salt is self-classified for toxicity to reproduction category 2, with the Hazard statement H361d (suspected of damaging the unborn child). The toxicological data on the assessment entity iron does support the conclusion that iron has no reproductive or developmental toxicity potential.