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PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB

Assessed composition:MEA-LAS (LE composition)


Annex XIII of the REACH Regulation (1907/2006) lays down the criteria for the identification of persistent, bioaccumulative and toxic substances (PBT substances), as well as the information that must be considered for the purpose of assessing the P, B, and T properties of a substance. The criteria require that all available information is to be used, employing a weight-of-evidence approach. Substances must meet all three criteria to be considered PBT.

The registered substance MEA-LAS easily dissociates into MEA (cation) and LAS (anion) ions in aqueous conditions. According to the registration dossier of MEA, it was found not to be a PBT compound. 

A PBT assessment was performed for the UVCB substance itself, as well as for the constituent that would represent a worst-case for lipophilicity (C13-LAS).

1) C10-13 LAS (UVCB - Benzenesulfonic acid, C10-13-alkyl derivs., sodium salts -(CAS No. 68411 -30 -3, EC No. 270 -115 -0)),

2) C13-LAS homologue (the most lipophilic active ingredient – typically 18.5% of C10-13 LAS) (CAS No. 6148-68-1).


Assessment of P/vP:


C10-13 LAS (UVCB): the substance was found to be readily biodegradable in the OECD 301B CO2 Evolution test, with 85% biodegradability in 29 days. Therefore, the substance is not persistent (section of the CSR).

C13 LAS: Biodegradation kinetics in river water and sediments found to be similar to C10, C11, C12 (Larson et al., 1990).  The commercial product with C13 in it is readily biodegradable.

Conclusion on P/vP: C10-C13 LAS and C13-LAS are readily biodegradable. The experimental demonstration that all homologues of LAS are biodegradable is consistent with the understanding of the biochemistry and pathways of the LAS biodegradation process.


Assessment of B/vB:


The bioaccumulation potential in fish was evaluated for the C10-13 LAS (UVCB – calculated as a weighted average value), as well as for the C13-homologue.


Estimation of BCF based on the Tollset al. 1997; Tolls, 1998 in vivo fish studies: In a flow-through study with fathead minnows (Tolls et al. 1997; Tolls, 1998), the mixture consisted of (where C indicates the length of the carbon chain; –[number] indicates the sulfophenyl group position, and –[in] indicates the sulfophenyl group was positioned on an internal carbon): C10-2, C11-2, C12-2, C13-2, C10-in, C11-in, C12-in, C13-in, average chain-length 10.6.

The resulting lipid normalized steady-state BCFs for the individual components in the mixtures ranged from 2.8 L/kg (C10-in) to 914 L/kg (C13-2). BCFs increased with increasing alkyl chain length for a given isomer and were higher when the p-sulfophenyl moiety was positioned closer to the terminal carbon of the alkyl chain.


In a flow-through study with rainbow trout (Tolls et al. 2000), the mixture in the study consisted of C10 -2, C11 -2, C12 -2 and C13 -2 with an average chain-length of 10.6. Whole body BCF values ranged from 1.4 L/kg (C10-2) to 372 L/kg (C13-2) for individual components of the LAS mixture. BCFs increased with increasing alkyl chain length. 

Estimation of BCF values for the registered commercial mixture: BCF values were determined for fathead minnow and rainbow trout using the mass percent of each individual chain length in the mixture as described in the Substance Identity Profile and measured C10 to C13 LAS BCF values from above (Tolls et al. 1997, Tolls 1998, Tolls et al. 2000). Estimated mixture BCF values using 2-phenyl isomers as a conservative approach were 250 L/kg and 103 L/kg for fathead minnow and rainbow trout, respectively.



To address remaining questions in the MEA-LAS Compliance Check, a pure C13 LAS was exposed to bluegill sunfish (Lepomismacrochirus) for 28 d at time-weighted mean measured concentrations of 0.019 and 0.035 mg/L followed by an 11 d depuration period in clean water (Schneider et al., 2020). BCFs were expressed as steady state (SS) and kinetic (K) values with lipid normalization and growth corrections. Uncorrected BCFss were 476 and 495 L/kg for 0.019 and 0.035 mg/L exposures, respectively and BCFk were 392 and 399 L/kg for 0.019 and 0.035 mg/L. Lipid normalized, growth-corrected BCFk values were 298 and 302 L/kg for 0.019 and 0.035 mg/L, respectively. Mean % lipid of bluegill ranged from 5.31-6.95% over the duration of the study. The BCF values are consistent with previously determined values for C13 LAS from Tolls et al. (1997, 1998, 2000).






BCF (L/kg)

Fathead minnow

Calculation based on measured C10-2 phenyl to C13-2 phenyl BCF values, mass percent of each chain-length in the mixture

C10-13 LAS Commercial mixture


Rainbow trout

Calculation based on measured C10-2 phenyl to C13-2 phenyl BCF values, mass percent of each chain-length in the mixture

C10-13 LAS Commercial mixture


Fathead minnow

Measured C10-2 phenyl to C13-2 phenyl BCF values; chain-length



Rainbow trout

Measured C10-2 phenyl to C13-2 phenyl BCF values; chain-length



Bluegill sunfish

Measured C13-2 phenyl BCF value




Conclusion on B / vB properties: C10-13 LAS (UVCB) and C13 LAS are not B and not vB based on an in-vivo BCF well below 2,000 L/kg.



Assessment of T:

None of the aquatic organisms tested in chronic test shows a NOEC <0.01 mg/l for C10-13 LAS (UVCB) or for the C13 homologue (see Table below). 

LAS is not classified as carcinogenic (Category 1 or 2), mutagenic (Category 1 or 2), or toxic for reproduction (Category 1, 2 or 3). There is no evidence of chronic toxicity, as identified by the classifications: T, R48, or Xn, R48 according to Directive 67/548/EEC. Therefore, LAS does not meet the PBT criteria for toxicity.


Overall conclusion: Based on the data collected and the discussion below, none of the three substances evaluated meet the criteria for either PBT or vPvB. This is justified by the fact that none of the substances meets the P or the T criteria. C10-13 LAS and C13 LAS do not qualify as B. The substances are also not classified as carcinogenic, mutagenic, or toxic for reproduction or for chronic toxicity.