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No toxicity data on adverse effects on reproduction with 2-ethylhexanoic acid, copper salt are available, thus the reproductive toxicity will be addressed with existing data on the individual assessment entities copper 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, copper salt is self-classified for Reproduction toxicity Category 2, with the Hazard statement H361d (suspected of damaging the unborn child).

Endpoint conclusion:

no adverse effect observed

Endpoint conclusion:

no study available

Endpoint conclusion:

no study available

Copper

The two-generation study in the rat indicate that under the conditions of this study, the no-observed-adverse-effect level (NOAEL) for reproductive toxicity was 1500 ppm, the highest concentration tested. The NOAEL for P1 and F1 rats and F1 and F2 offspring during lactation was 1000 ppm, based on reduced spleen weight in P1 adult females, and F1 and F2 male and female weanlings at 1500 ppm however the transient reduced spleen weights are not considered a reproductive endpoint as it did not affect growth or fertility.

In compliance with the “Definition of reproductive toxicity”, OECD document ENV/JM/MONO(2001)6 the spleen effect cannot be considered a reproductive effect as this must include:

1) Adverse effects on sexual function and fertility in adult males and females

2) Developmental toxicity in the offspring

For a compound to be considered to be a reproductive toxin “data for animal studies ideally should provide clear evidence of specific reproductive toxicity in the absence of other, systemic, toxic effects”. Therefore as the results of this study do not indicate specific reproductive toxicity at the highest dose level tested, it is proposed that copper sulphate and, after read across, copper are not classified as reproductive compounds.

A further high quality study by Chung et al (2008) provides supportive evidence. This study is a combined repeat dose and reproduction/developmental screening test, which is intended to investigate effects of repeated exposure over a relatively limited time-period and to provide initial information on effects on male and female reproductive performance. The study was conducted according to OECD test guidances (no. 422) and is considered to be of high quality. In this study, male rats were treated with copper chloride two weeks prior to mating and during the mating period (total of 30 days). Female rats were treated two weeks prior to mating, throughout mating and gestation, and until day 3 of lactation (estimated duration ~50 days). Copper chloride was administered daily as an aqueous suspension by gavage at 1.3, 5, 20 and 80 mg/kg bw/d (calculated as 0.8, 3.2, 12.9 and 51.7 mg Cu/kg bw/d). With regard to general effects of repeated exposure, systemic toxicity was evident at 80 mg/kg bw/d, consisting of some altered haematological parameters (males and females), changes in some biochemical parameters (males only) and increased incidence of femoral marrow hyperplasia (males only). With regard to reproduction/developmental effects, there were no effects on any male or female reproductive parameters investigated in this study. Effects on two developmental parameters were reported: numbers of pups with gross (icteric) lesions and numbers of runt pups, both of which were significantly increased at 80 mg/kg bw/d (51.7 mg Cu/kg bw/d).

Squamous cell hyperplasia of the stomach showed a significant, dose-related increase in males at 20 mg/kg bw/d and above and in females at 5 mg/kg bw/d and above. These effects, which were considered to be a direct effect of the irritant properties of copper chloride, are not consider relevant for the hazard profile of copper metal.

In the developmental toxicity study (Munley 2003), groups of 22 female NZW rabbits were treated orally by gavage on days 7 to 28 of pregnancy with copper hydroxide (0, 6, 9 or 18 mg Cu/kg/bw/day). A preliminary range-finding test, conducted in non-pregnant rabbits, indicated there were no marked differences between several copper compounds (including copper hydroxide, copper (I) oxide and copper oxychloride) in terms of maternal toxicity.

In the main study, maternal toxicity was evident at 9 and 18 mg Cu/kg/bw/day. Initial weight loss and reduced food intake occurred at 9 and 18 mg/kgBW/day, followed by partial recovery during the middle/late pregnancy. At the end of the study, bodyweight gain in these two groups was 31% and 72% lower than controls and total food consumption 17% and 30% lower than controls, respectively. Three deaths and two abortions occurred at 18 mg/kgBW/day which appeared to be related to treatment; necropsy of decedents and one aborted animal showed haemorrhagic and/or ulcerative changes in the stomach lining. No deaths occurred at 9 or 6 mg/kg/bw/day. At 9 mg/kg/bw/day, there were no abortions. At 6 mg/kg/bw/day, there was a single abortion on day 27. This abortion was not considered to be treatment-related in view of the absence of abortions at the higher dose level and earlier occurrence of abortions at 18 mg/kg/bw/day. At 6 mg/kg/bw/day, and bodyweight gain and food intake were only marginally lower than controls. There was no difference between treatment groups and controls in the number of pregnant females, or the number of females showing total resorption or with live offspring. There was no difference between treatment and control groups in the number of corpora lutea, implantations, embryonic deaths, live young or percentage of males in litter. At 18 mg/kg/bw/day, mean foetal weight was slightly lower than in controls (9% less). Four malformed foetuses occurred in the study: one with fused ribs (control group); one with ectopic kidney (6 mg/kg/bw/day); two with hemivertebra (18 mg/kg/bw/day). These malformations were all considered to be unrelated to treatment. With regard to fetal skeletal abnormalities, retarded ossification of pelvis and skull showed a slightly increased incidence at 18 mg/kg/bw/day and occurrence of extra ribs was increased at 9 and 18 mg/kg/bw/day compared to controls. It was noted that the occurrence of extra ribs was a common finding in all treatment groups, including the control group (64%, 67%, 80% and 87% incidence at 0, 6, 9 and 18 mg/kg/bw/d, respectively). With regard to fetal visceral abnormalities, none were recorded for any treatment or control group. In conclusion, this study demonstrated maternal toxicity (initial weight loss and reduced food intake) and effects on the fetus (increased incidence of a common skeletal abnormality) following oral exposure of rabbits to copper hydroxide at 9 mg Cu/kg/bw/day and above during pregnancy. There were no indications of fetal abnormalities associated with treatment at up to maternally toxic levels. The NOAEL for maternal toxicity and developmental effects in rabbits in this study was 6 mg Cu/kg/bw/day. Effects on the fetus were considered to be secondary to maternal toxicity and consequently not a specific effect of copper on reproduction.

Maternal toxicity, reported in this study at 9 mg/kg/bw/day, was represented by initial weight loss. These effects are considered to be local effects on the stomach in rabbits which result from gavage administration of copper hydroxide. Consequently, it is considered inappropriate to use data on maternal toxicity from this study as the basis of a repeat-dose NOAEL for copper.

The two generation oral reproduction study, performed in accordance with OECD test guideline 416, provides information on the effects of repeated exposure to the substance during all phases of the reproductive cycle including gestation. In particular, the study provides information on the reproductive parameters, and on development, growth and survival of offspring.

The NOAEL for reproductive toxicity was 1500 ppm, the highest concentration tested. The NOAEL for P1 and F1 rats and F1 and F2 offspring during lactation was 1000 ppm, based on reduced spleen weight in P1 adult females, and F1 and F2 male and female weanlings at 1500 ppm. However the transient reduced spleen weights were not considered a reproductive endpoint as it did not affect growth and fertility.

In compliance with the “Definition of reproductive toxicity”, OECD document ENV/JM/MONO(2001)6 the spleen effect cannot be considered a reproductive effect as this must include:

• Adverse effects on sexual function and fertility in adult males and females

• Developmental toxicity in the offspring

For a compound to be considered to be a reproductive toxin “data for animal studies ideally should provide clear evidence of specific reproductive toxicity in the absence of other, systemic, toxic effects”

The dietary concentration of 1000 ppm was equivalent to mean daily intakes of copper of 15.2-23.5 mg/kg body weight/day for male rats during premating and 17.0-35.2 mg/kg body weight/day for female rats during premating, gestation and the first 2 weeks of lactation.

Although the principal aim of this study was to investigate reproduction toxicity it also provides important information on the developmental toxicity potential of the test substance. Notably, investigation of F1 and F2 litters showed no test substance related effects on the following parameters:

• pups survival, sex ratio, and survival indices during the lactation period, body weights and clinical observations during lactation,

• macroscopic examination of pups that died during the lactation period, of weanlings with external abnormalities or clinical signs and of randomly selected weanlings,

• microscopic observations of any gross findings and of liver and brain from randomly selected high-dose and control weanlings.

It is therefore considered that all major manifestations of developmental toxicity (including mortality, structural abnormality, altered growth and functional deficiency) are adequately investigated in this study.

The results of the multigeneration study should also be interpreted in conjunction with the rest of the toxicology data base for copper. The following findings are considered relevant when evaluating the reproductive and developmental toxicity potential of the test substance:

• Subchronic and chronic studies show no adverse effects on reproductive organs or endocrine functions,

• Copper salts show no indication of genotoxicity,

It is also important to consider that copper is an essential element and many countries recommend an increased dietary intake of copper during pregnancy. This increased recommendation is because a foetus requires copper levels up to 10 times adult levels. The copper is absorbed across the placenta and is required for healthy growth and development, especially in blood maturation, bone development, heart development and function, brain development and function and the function of 20 key enzymes (Ralph & McArdle, 2001).

The existing toxicology data package therefore supports the conclusion that copper has no reproductive or developmental toxicity potential.

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, copper salt

Since no reproductive toxicity study is available for 2-ethylhexanoic acid, copper salt, information on the individual assessment entities copper and 2-ethylhexanoic acid will be used for the hazard assessment and, when applicable, also 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.

No toxicity data on adverse effects on reproduction with 2-ethylhexanoic acid, copper salt are available, thus the reproductive toxicity will be addressed with existing data on the individual assessment entities copper 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, copper salt is self-classified for Reproduction toxicity Category 2, with the Hazard statement H361d (suspected of damaging the unborn child).

Endpoint conclusion:

adverse effect observed