Phenol, mono- + distyrenated (MSP+DSP)

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

11.5 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

13.5 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

1.15 µg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

10 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

1.564 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.156 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.305 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Deduction of PNECs is based on the Guidance Document 'Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment" (TGD R.10) published by the European Chemicals Agency, 2008.

 

The substance phenol, mono- & distyrenated (LS 500) consists essentially of three constituents: 2-(1-phenylethyl)phenol (2-MSP), 4-(1-phenylethyl)phenol (4-MSP), and 2,4-bis(1-phenylethyl)phenol (DSP) in a ratio of approx. 2:4:3. The portion of monostyrenated phenols in LS 500 amounts to approx. 50 - 70 percent. A minor component (ca. 0.2 to 5 %) is 2,4,6-tris(1-phenylethyl)phenol (TSP). PNECs for phenol, mono- & distyrenated were derived using the parameters specified in the endpoint summaries related to phenol, mono- & distyrenated. For sediment freshwater and marine water and for soil, PNECs were estimated using the equilibrium partioning method (see below).

 

When using the equilibrium partitioning method, values for Koc and Henry's Law Constant (HLC) are required in calculating the PNECs. As measured values for theses parameters are not available for LS 500, calculated/estimated values are employed.

 

Due to the differences in Koc values of the components, PNECs sediment and soil are much lower for monostyrenated phenols than for distyrenated and tristyrenated phenols. As values for Koc and Henry's Law Constant cannot be calculated for the LS 500 mixture and as values for monostyrenated phenols result in much lower PNECs for sediment and soil compared to distyrenated/tristyrenated phenol, data for 2-(1-phenylethyl)phenol (mono-styrenated phenol) is used in the deduction of PNECs sediment and soil standing as a worst case for the substance LS 500. In addition, the use of monostyrenated phenol in the calculation of PNEC sediment and soil is justified as monostyrenated phenols account for about 50 - 75% of phenol, mono- & distyrenated (LS500).

 

PNECs aqua (freshwater / marine water) have been derived based on measured aquatic toxicity data. These PNECs are entered in the equilibrium partitioning calculations.

 

Estimates for Koc and HLC are taken from the respective programmes of US EPA EPIWIN v.4.1. The calculation methods are well established and validated according to acknowledged rules. Results are considered valid within the range and scope of the calculation methods. Results for 2-(1-phenylethyl)phenol and 4-(1-phenylethyl)phenol are practically identical. The values for 2-(1-phenylethyl)phenol are reported in IUCLID (Sect. 5.4.1 and 5.4.2) or in the CSR (Chapter 4.2.1. and 4.2.2.) and taken for the calculations.

 

PNEC sediment (freshwater)

According to chapter R.10.5.2.1 of TGD R.10, the PNEC sediment can provisionally be calculated in the absence of data for sediment-dwelling organisms using the equilibrium partitioning method (EPM).

PNEC derivation following procedures of TGD R.10 and R.16:

PNEC aqua (freshwater): 11.5 µg/L,

Koc: 1,324 (US EPA EPI Suite estimate, program KOCWIN v2.00, Koc estimate from log Kow; see IUCLID Sect. 5.4.1 or CSR Chapt. 4.2.1.),

The PNEC sediment (freshwater) was calculated to 0.340 mg/kg ww. This value was converted into dry weight (conversion factor of 4.6) resulting in a PNEC sediment (freshwater) of 1.564 mg/kg sediment dw.

 

PNEC sediment (marine water)

According to chapter R.10.5.3.1 of TGD R.10, the PNEC sediment can provisionally be calculated in the absence of data for sediment-dwelling organisms using the equilibrium partitioning method (EPM).

PNEC derivation following procedures of TGD R.10 and R.16:

PNEC aqua (marine water): 1.15 µg/L,

Koc: 1,324 (US EPA EPI Suite estimate, program KOCWIN v2.00, Koc estimate from log Kow; see IUCLID Sect. 5.4.1 or CSR Chapt. 4.2.1.),

The PNEC sediment (marine water) was calculated to 0.34 mg/kg ww. This value was converted into dry weight (conversion factor of 4.6) resulting in a PNEC sediment (marine water) of 1.564 mg/kg sediment dw.

 

PNEC soil

According to chapter R.10.6.1 of TGD R.10, the PNEC soil can provisionally be calculated in the absence of data for soil organisms using the equilibrium partitioning method (EPM).

PNEC derivation following procedures of TGD R.10 and R.16:

PNEC water (freshwater): 11.5 µg/L,

Koc: 1324 (US EPA EPI Suite estimate, program KOCWIN v2.00, Koc estimate from log Kow; see IUCLID Sect. 5.4.1 or CSR Chapt. 4.2.1.),

HLC: 0.0364 Pa*m³/mol (US EPA EPI Suite estimate, program HENRYWIN v3.20; see IUCLID Sect. 5.4.2 or CSR Chapt. 4.2.2.);

The PNEC soil was calculated to 0.27 mg/kg ww. This value was converted into dry weight (conversion factor of 1.13) resulting in a PNEC soil of 0.305 mg/kg soil dw.

 

Secondary poisoning

For LS 500 itself, no data on bioaccumulation in the food chain are available.

For the closely related substance cumylphenol (4-(α,α-dimethylbenzyl)phenol, 4-(1-methyl-1-phenylethyl)phenol), a BCF in fish (cyprinus carpio) of 69 - 190 (8 wks, steady state) has been determined (concentration in medium 10 and 1 µg/L) (National Institute of Technology and Evaluation, Japan, 2002). The substance is assessed as not being bioaccumulative.

In a flow-through feeding study (Scheerbaum D 2008, reported in Brooke et aL: 2009: "Environmental risk evaluation report: Styrenated phenol" Environmental Agency, Bristol, UK 2009, ISBN 978-1-84911-162-1), it was found, that distyrenated phenol did not accumulate in fish fed with diet containing 342 ± 50 mg/kg food. After uptake at day 1 and day 5 (concentrations of 5.89 and 3.95 mg/kg fish, respectively), the substance concentrations in fish decrease to a level below detection at day 10. Results can be interpreted that metabolism and elimination are induced by the substance and exceed its uptake from diet by day 5 to 10.

Both results indicate that bioconcentration of phenol, mono- &distyrenated (LS 500) in the food chain is of no concern.

Conclusion on classification

Based on available data, phenol, mono- & distyrenated is classified as Aquatic Chronic 2 according to Regulation (EC) 1272/2008 (CLP regulation).