Reaction mass of 2-ethylhexyl diphenyl phosphite and bis(2-ethylhexyl) phenyl phosphite and triphenyl phosphite

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence(P, vP)

There are no biodegradation studies on 2 -ethylhexyl diphenyl phosphite (2EHDPP); however, a study on triphenyl phosphite (TPP), which is a constituent of 2 -EHDPP and a close analog, showed rapid biodegradation in a recently OECD 301D study. This new data on TPP also supports the theorgy that these phosphites rapidly hydrolyze in the environment and that their hydrolysis products readily biodegrade.

Based on this related test data and the very short half-lives in water, 2EHDPP is not expected to meet the criteria for P or vP. The hydrolysis products of 2EHDPP (2-ethylhexanol, phenol and phosphorous acid) are readily biodegradable are also do not meet the criteria for P or vP.

Bioaccumulation (B, vB)

Bioaccumulation concentration factor (BCF) cannot not be measured for 2EHDPP due to its rapid hydrolysis. The BCF model estimates for 2EHDPP are likely to be of limited utility given their uncertainties in the model parameters and the fact that hydrolysis is not considered in the model. Given the rapid hydrolysis, the bioaccumulation potential of the hydrolysis products, 2-ethylhexanol, phenol and phosphorous acid, were considered. All are well below the criterion for B (bioaccumulative) or vB (very bioaccumulative). As such, it is concluded that 2EHDPP does not meet the criteria for B or vB.

Toxicity (T)

The primary toxicity effect is skin sensitisation; for which 2EHDPP is classified. Based on 2EHDPP’s low water solubility and rapid hydrolysis, it is not anticipated to cause aquatic toxicity based on the amount and relatively aquatic toxicity of its hydrolysis products. None of its hydrolysis products (2-ethylhexanol, phenol and phosphorous acid) are classified as dangerous to the environment.)

(Note Phenol recently self classified for the environement due to CLP criteria)

PBT/vPvB criteria and justification

2EHDPP is not classifiable as a PBT or a vPvB substance as it does not meet criteria for either persistence or bioaccumulation and toxicity effects are primarily related to its potential for skin sensitisation.

It should be noted that the ECB PBT Working Group review diisodecyl phenyl phosphite (DDPP), a related substance, and the conclusion from their assessment was that DDPP is not a PBT or vPvB substance based on hydrolysis. This conclusion should also be applicable to 2EHDPP.

NOTE C&L Update 2015

Update 2015

Diphenyl 2 -ethylhexyl phosphitePhosphite

Composition: multiconstituent substance with 2 moles phenyl to 1 mole 2 -ethylhexanol, contains ~ 10 -20% TPP

Maximum theoretical hydrolysis yield: ~55% phenol

 Phenol classification was recently updated as a consequence of the CLP rules

TPP content

Although the Annex VI classification of TPP may be contested on the basis of the phenol content and the rapid hydrolysis, the registrant has updated the classification of this phosphite to H411 on the basis of the TPP content

This is derived from <25% of TPP

Proposed Change:

H411 – Aquatic Chronic 2

Based on new classification of H411 for phenol, which is predominant hydrolysis product. Note that this classification would also address the fact that the substance contains approximately 15% TPP.