Feropur

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

NaOH is not expected to be systemically available in the body under normal handling and use conditions and for this reason it can be stated that the substance will not reach the foetus nor reach male and female reproductive organs (EU RAR of sodium hydroxide (2007), section 4.1.2.8, page 73). It can be concluded that a specific study to determine the toxicity to reproduction is not necessary.

Additional information

When in contact with water, the constituents of Feropur will be degraded within seconds to Na⁺,OH^-and H₂. Consequently, Na₂O and NaH are considered to be too short-living and hence irrelevant for the assessment of environmental and toxicological effects. Based on the very quick and complete degradation of Na₂O and NaH to NaOH, the risk assessments for the environment and humans are based on the properties of NaOH and Na₂CO₃.

This approach was discussed with ECHA (see attached document: "Strategy paper Feropur ECHA 090813.pdf"). ECHA agreed on this approach (see attached document "reply ECHA 090902.pdf").

The hazards of NaOH and Na₂CO₃ for the environment are caused by the hydroxyl ion and carbonate ion, respectively, and hence by an effect on the pH, i.e., both ions will increase the pH. However, the impact on the pH-effect of the carbonate ion is much weaker than the impact of the hydroxyl ion. In the SIDS dossier of sodium carbonate (SIDS dossier for sodium carbonate, 2002, Table 1, page 10, see attached document) it is outlined that 603 mg sodium carbonate/L are needed to increase the pH of distilled water to a pH of 11. To cause the same effect with sodium hydroxide, only 40 mg sodium hydroxide/L is needed (SIDS dossier for sodium hydroxide, 2002, Table 1, page 10, see attached document). Hence, the effects of sodium carbonate are about 15 times weaker than for sodium hydroxide. In addition, the concentration of sodium carbonate is only about 5% in Feropur. When in contact with water, the degradation products consists to about 95 % of sodium hydroxide and about 5% of sodium carbonate (see attached document "Strategy paper Feropur ECHA 090813.pdf"). When multiplying the concentration with the efficiency of sodium carbonate relative to sodium hydroxide (1/15th), i.e., 5%*1/15, the impact of sodium carbonate in Feropur would be about 0.3% when compared to the effect of sodium hydroxide in Feropur. Na₂CO₃ is registered as food additive E500i and may be added quantum satis to food and is therefore considered to be a substance of “low priority".

Based on the same mode of action and the much weaker effect of sodium carbonate in combination with the much lower content of sodium carbonate in Feropur when compared to sodium hydroxide, it can be concluded that the risk of Feropur is sufficiently described by the risk resulting from sodium hydroxide alone.

No valid studies were identified regarding developmental toxicity nor toxicity to reproduction in animals after oral, dermal or inhalation exposure to NaOH (EU RAR, section 4.1.2.8, page 73).

It is not useful to do a reproduction or developmental toxicity test with NaOH in rats because the hazard of sodium for humans has been characterized sufficiently (e.g. Fodor et al., 1999). It is also not useful to study the reproduction/developmental toxicity of hydroxide via an oral study because at high concentrations the substance is corrosive or irritating, while at low concentrations the hydroxide will be neutralized in the stomach by gastric juice, which has a very low pH. Furthermore, oral exposure to NaOH is negligible under normal handling and use conditions and therefore an oral reproduction/developmental toxicity study is inappropriate.

NaOH is not expected to be systemically available in the body under normal handling and use conditions and for this reason it can be stated that the substance will not reach the foetus nor reach male and female reproductive organs. It can be concluded that a specific study to determine the developmental toxicity or the toxicity to reproduction is not necessary.

This is also true for Feropur.

Short description of key information:
NaOH is not expected to be systemically available in the body under normal handling and use conditions and for this reason it can be stated that the substance will not reach the foetus nor reach male and female reproductive organs (EU RAR of sodium hydroxide (2007), section 4.1.2.8, page 73). It can be concluded that a specific study to determine the developmental toxicity or the toxicity to reproduction is not necessary.

Effects on developmental toxicity

Description of key information

NaOH is not expected to be systemically available in the body under normal handling and use conditions and for this reason it can be stated that the substance will not reach the foetus nor reach male and female reproductive organs (EU RAR of sodium hydroxide (2007), section 4.1.2.8, page 73). It can be concluded that a specific study to determine the developmental toxicity or the teratogenicity is not necessary.

Justification for classification or non-classification

Classification for reproductive or developmental toxicity is not necessary since NaOH is not expected to be systemically available in the body under normal handling and use conditions and the substance will not reach the foetus nor reach male and female reproductive organs (EU RAR of sodium hydroxide (2007), section 4.1.2.8, page 73).

This non-classification is also relevant for Feropur.