Fatty acids, C9-13-neo-, zinc salts

Endpoint summary

Description of key information

Fatty acids, C9-13-neo-, zinc salt is not expected to show acute toxic effects via oral and dermal route.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Introduction to read-across matrix

A comprehensive data gap analysis was conducted for the entire substance portfolio of the Metal carboxylates REACH Consortium (MCRC), covering 10 metal carboxylates in total. This literature screening effort included:

 

• all available proprietary studies from the Metal carboxylates REACH Consortium (MCRC)
• detailed literature searches in online databases
• screening of human health review articles
• rigorous quality and reliability screening according to Klimisch criteria, where those criteria apply

 

During the literature search and data gap analysis it became obvious that the overall database on substance-specific human health hazard data for the metal carboxylates is too scant to cover all REACH endpoints. Therefore, the remaining data gaps had to be covered by either experimental testing or read-across from similar substances.

 

Selected endpoints for the human health hazard assessment are addressed by read-across, using a combination of data on the organic acid counterion and the metal (or one of its readily soluble salts). This way forward is acceptable, since metal carboxylates dissociate to the organic anion and the metal cation upon dissolution in aqueous media. No indications of complexation or masking of the metal ion through the organic acid were apparent during the water solubility tests (please refer to the water solubility data in section of the IUCLID and chapter of the CSR). Once the individual constituents of the metal carboxylate become bioavailable (i.e. in the acidic environment in the gastric passage or after phagocytosis by pulmonary macrophages), the “overall” toxicity of the dissociated metal carboxylate can be described by the toxicity of the “individual” constituents. Since synergistic effects are not expected for this group of metal carboxylates, the human health hazard assessment consists of an individual assessment of the metal cation and the organic anion.

 

The hazard information of the individual constituents was obtained from existing REACH registration dossiers via a license-to-use obtained by the lead registrant. These registration dossiers were submitted to ECHA in 2010 as full registration dossiers, and are thus considered to contain relevant and reliable information for all human health endpoints. All lead-registrant dossiers were checked for completeness and accepted by ECHA, i.e. a registration number was assigned.

 

Fatty acids, C9-13-neo-, zinc salts is the zinc metal salt of fatty acids, C9-13-neo, which readily dissociates to the corresponding divalent zinc cation and fatty acids, C9-13-neo anions. The zinc cation and the fatty acids, C9-13-neo anion are considered to represent the overall toxicity of the Fatty acids, C9-13-neo-, zinc salts in a manner proportionate to the free acid and the metal (represented by one of its readily soluble salts). Based on the above information, unrestricted read-across is considered feasible and justified.

 

Introduction to the neo acids hazard assessment

The carboxylic acids “fatty acids, C9-13-neo” and “neodecanoic acid” are considered similar in their toxicological profile and are therefore grouped together. Both neo acids originate from the same production process in which a branched olefin is reacted with carbon monoxide and water at elevated temperature and pressure in the presence of an acid as catalytic component. The dossiers for fatty acids, C9-13-neo and neodecanoic acid contain human health hazard information on both substances indicating that the toxicological profile is similar. This approach was also used and accepted in the US EPA HPV programme, even for a wider range of neo-acid substances (US EPA, April 2009: http://www.epa.gov/chemrtk/pubs/summaries/neoc528/c13335tc.htm).

Based on the above information “fatty acids, C9-13-neo” and “neodecanoic acid” will be assessed for their hazardous properties, using the same dataset for both substances.

Although the term „constituent“ within the REACH context is defined as substance (also being part of a mixture), the term constituent within this hazard assessment is meant to describe either part of the metal carboxylate salt, i.e. anion or cation.

Acute toxicity

No acute toxicity studies with Fatty acids, C9-13-neo-, zinc salts are available, thus the acute toxicity will be addressed with existing data on the dissociation products as detailed in the table below. Further details on the acute toxicity of the individual constituents within the framework of regulation (EC) 1907/2006 are given below.

 

Table: Summary of acute toxicity data of Fatty acids, C9-13-neo-, zinc salts and the individual constituents.

	(slightly soluble) zinc substances	Fatty acids, C9-13-neo (CAS# 68938-07-8)	Fatty acids, C9-13-neo-, zinc salts (CAS# 92044-84-3)
Acute oral toxicity	LD50(rat)>2,000 mg/kg bw	LD50(rat)=2,066 mg/kg bw (read-across from neodecanoic acid)	LD50(rat)>2,000mg/kg bw (calculated)
Acute inhalation toxicity	LC50>5.7mg/L	LC50(mice and rats)> 3mg/L air (nominal, 6h exposure)   (read-across from neodecanoic acid)	waived, since the substance is used and placed on the market in a non-inhalable form
Acute dermal toxicity	LD50(rabbit)> 2,000 mg/kg bw	LD50(rat)>3,640 mg/kg (read-across from neodecanoic acid)	LD50(rat)> 2,000 mg/kg (calculated)

 

Signs of acute oral or acute dermal toxicity are not expected for Fatty acids, C9-13-neo-, zinc salts, since the two constituents zinc and fatty acids, C9-13-neo have not shown signs of acute oral or acute dermal toxicity in experimental testing (both LD50>2000mg/kg). Under the assumption that the constituents of Fatty acids, C9-13-neo-, zinc salts show their toxicological profile individually upon dissolution, the acute oral and dermal (systemic) toxicity of Fatty acids, C9-13-neo-, zinc salts can be calculated using the equation given in regulation (EC) 1272/2008, Annex I, Section 3.1.3.6.1. The calculated oral and dermal LD50 for Fatty acids, C9-13-neo-, zinc salts is > 2000mg/kg, hence the substance is not to be classified according to regulation (EC) 1272/2008 for acute oral and dermal toxicity as well as for specific target organ toxicity, single exposure (STOT SE). Further testing is not required. For further information on the toxicity of the individual constituents, please refer to the relevant sections in the IUCLID and CSR.

Justification for selection of acute toxicity – oral endpoint
Read-across information.

Justification for selection of acute toxicity – dermal endpoint
Read-across information.

Justification for classification or non-classification

The calculated oral and dermal LD50 for fatty acids, C9-13-neo-, zinc salts

is > 2000mg/kg, hence the substance is not to be classified according to regulation (EC) 1272/2008 for acute oral and dermal toxicity as well as for specific target organ toxicity, single exposure (STOT SE).

Furthermore, according to Directive 67/548 EC, a classification and labelling for acute oral and dermal toxicity of fatty acids, C9-13-neo-, zinc salts

is not required. Further testing is not required. For further information on the toxicity of the individual constituents, please refer to the relevant sections in the IUCLID and CSR.