Potassium 2-ethylhexanoate

Endpoint summary

Description of key information

Potassium 2-ethylhexanoate  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.

 

Potassium 2-ethylhexanoate is the potassium metal salt of 2-ethylhexanoic acid, which readily dissociates to the corresponding monovalent potassium cation and 2-ethylhexanoic acid anions. The potassium cation and the 2-ethylhexanoic acid anion are considered to represent the overall toxicity of the potassium 2-ethylhexanoate 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.

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 potassium 2-ethylhexanoate 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 potassium 2-ethylhexanoate and the individual constituents.

	potassium substances	2-ethylhexanoic acid (CAS# 149-57-5)	Potassium 2-ethylhexanoate (CAS# 3164 -25 -0)
Acute oral toxicity	not acutely toxic in humans   LD50(rat)>2,000 mg/kg bw (supporting data)	LD50(rat)= 2,043 mg/kg bw	LD50>2,000 mg/kg bw (calculated)
Acute inhalation toxicity		LD0= 0.11 mg/L air (nominal)	waived, since the substance is used and placed on the market in a non-inhalable form
Acute dermal toxicity		LD50> 2,000 mg/kg bw	LD50>2,000 mg/kg bw (calculated)

 

Signs of acute oral or acute dermal toxicity are not expected for potassium 2-ethylhexanoate, since the two constituents potassium and 2-ethylhexanoic acid have not shown signs of acute oral or acute dermal toxicity. Under the assumption that the constituents of potassium 2-ethylhexanoate show their toxicological profile individually upon dissolution, the acute oral and dermal (systemic) toxicity of potassium 2-ethylhexanoate 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 potassium 2-ethylhexanoate 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 potassium 2-ethylhexanoate 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 potassium 2-ethylhexanoate is not required.