Ethanaminium, 2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethyl-, esters with C16-18 and C18-unsatd. fatty acids, chlorides

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification

Qualifier:

no guideline followed

Principles of method if other than guideline:

The bioconcentration factor BCF of MDEA-Esterquat C16-18 and C18 unsatd. was calculated using EPIWIN v3.20, BCFWIN v2.17.

GLP compliance:

no

Radiolabelling:

no

Test organisms (species):

other: fish

Type:

BCF

Value:

70.8 L/kg

The bioconcentration factor BCF of MDEA-Esterquat C16-18 and C18 unsatd. was calculated using EPIWIN v3.20, BCFWIN v2.17. The calculation yielded a BCF=70.8 L/kg indicating a low bioaccumulation potential. Due to missing information about the applicability of the calculation model in respect to the substance under investigation the result and the conclusion thereof should be treated with care.

Validity criteria fulfilled:

not applicable

Conclusions:

The bioconcentration factor BCF of MDEA-Esterquat C16-18 and C18 unsatd. was calculated using EPIWIN v3.20, BCFWIN v2.17. The calculation yielded a BCF=70.8 L/kg indicating a low bioaccumulation potential. Due to missing information about the applicability of the calculation model in respect to the substance under investigation the result and the conclusion thereof should be treated with care.

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Further information is included in the detailed justification for read-across in the endpoint summary “Bioaccumulation”.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substance have similar environmental fate properties based on similar physicochemical properties, common functional groups and structural similarities.
The target substance MDEA-Esterquat C16-18 and C18 unsatd. (Reaction products of C16-18/C18 unsaturated fatty acid with methyl diethanolamine, MeCl quaternised) is a UVCB substance consisting of diesters of mainly saturated C16 and C18 fatty acids with MDEA (Methyldiethanol amine) as amine backbone.
The source substances DODMAC and DHTDMAC exhibit large structural similarities with the target substance. Details are described below.
Therefore, read-across from the existing bioaccumulation data on the source substance is considered as an appropriate adaptation to the standard information requirements of Annex IX, 9.3 of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Further information is included in the detailed justification for read-across in the endpoint summary “Bioaccumulation”.

3. ANALOGUE APPROACH JUSTIFICATION
Further information is included in the detailed justification for read-across in the endpoint summary “Bioaccumulation”.

4. DATA MATRIX
Further information is included in the detailed justification for read-across in the endpoint summary “Bioaccumulation”.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Key result

Type:

BCF

Value:

13 L/kg

Basis:

other: whole body

Remarks on result:

other: river water

Type:

BCF

Value:

32 L/kg

Basis:

other: whole body

Remarks on result:

other: laboratory water

Type:

BCF

Value:

< 5 L/kg

Basis:

edible fraction

Remarks on result:

other: river water, laboratory water

Type:

BCF

Value:

94 L/kg

Basis:

non-edible fraction

Remarks on result:

other: river water

Type:

BCF

Value:

256 L/kg

Basis:

non-edible fraction

Remarks on result:

other: laboratory water

Conclusions:

A BCF of 13 L/kg is used for risk assessment based on the available data.

Description of key information

For MDEA-Esterquat C16-18 and C18 unsatd. a BCF of the same order of magnitude as the BCF of the structurally related source substance DODMAC (13 L/kg) is expected.

Key value for chemical safety assessment

BCF (aquatic species):

13 L/kg ww

Additional information

No data are available on MDEA-Esterquat C16-18 and C18 unsatd. According to REACH regulation (Annex XI, 1.5), the study on aquatic bioaccumulation does not need to be conducted for the substance under investigation if data from a structurally closely related material are available (a justification for read-across is given in the endpoint summary "Bioaccumulation").

Measured BCF data are available on a structurally closely related material, DODMAC (Dimethyldioctadecylammonium chloride, CAS-No. 107-64-2; see Figure 1a). DODMAC has a chemical structure similar to the compound Dimethylbis[2-[(1-oxooctadecyl)oxy]ethyl]ammonium chloride (compound I). Compound I (please refer to table 2, page 9: Ethanaminium, 2-hydroxy-N-(2-hydroxyethyl)-N,N-dimethyl-, diesters with C16-18 and C18-unsatd. fatty acids, chlorides ca. 90%) is the molecular moiety of the registration substance (MDEA-Esterquat; see Figure 1b) for which the highest bioaccumulation potential is expected (1). Compound I differs from DODMAC by the ester linking groups between the alkyl chains (of C18 chain length) and the head group (effectively the dimethylammonium group).

Regarding BCF of the registration substance, the registration substance BCF is expected to be lower than the BCF for DODMAC:

The chemical structure of the registration substance includes, in contrast to DODMAC, two polar ester moieties that lower BCF and are biodegradable/hydrolysable which also will result in a lower BCF for the registration substance. DODMAC is poorly biodegradable and much more stable than the registration substance. For DODMAC no abiotic degradation is expected, for biotic degradation in water the degradation rate is very low (1.4·10-4 day-1) (EU RAR, 2002).

Juvenile fish (Pimephales promelas) were exposed to DODMAC for 24 h under flow-through conditions, followed by a depuration period of 72 h. Without Humic acid, a BCF of 103.8 L/kg could be calculated based on the uptake rate constant (k1) of 1.35 mg/g x h and the depuration rate constant (k2) of 0.013 mg/g x h. With the addition of 1 mg/L and 6.8 mg/L Humic acid, the BCF was 37.5 and 2.8 L/kg, respectively. (Versteeg & Shorter, 1992).

Based on naturally occurring concentrations of dissolved organic carbon (DOC) in the range of 2 to 10 mg/L in rivers and lakes, and 50% of the DOC being fulvic and humic acids (Thurman, 1985 (4)), the BCF obtained with the addition of 1 mg/L Humic acid can be considered to be most relevant.

The measured BCF values for similar substances (DODMAC, DHTDMAC(2)) are 12-32 (BUA Report 191, 1995) and 13-256 (EU RAR, 2002). The conclusion for DODMAC was “bioaccumulation is indicated, but it is assumed that it is low under environmental conditions. A BCF of 13 L/kg is used in the risk assessment…” (EU RAR, 2002).

The calculated BCF value for MDEA-Esterquat C16-18 and C18 unsatd.is 70.8 L/kg (BCFWIN v2.17; CFCS 2009).

The low bioavailability of the substance (due to rapid and strong sorption to negatively charged surfaces in the aquatic environment) in combination with the rapid (bio)degradation of the bioavailable fraction (mainly due to the hydrolysis of the ester bond), make high bioconcentration factors for the substance even more improbable (Comber et al., 2003 in Hera, 2008).

For MDEA-Esterquat a BCF of the same order of magnitude as the BCF of DODMAC (13 L/kg) is expected. The above information is considered as sufficient to support to the conclusion that the bioaccumulation potential of the registration substance is expected to be low (3).

(1) for a fatty acid derivative like the registration substance, bioaccumulation potential increases with increasing chain length of the fatty acid (within certain limits). Compound I has the longest fatty acid chain length among the molecules forming the registration substance.

(2) DHTDMAC: Dihydrogenated Tallow Alkyl Dimethyl Ammonium Chloride

(3) REACH Regulation, Annex XIII: a substance fulfils the bioaccumulation criterion when the bioconcentration factor (BCF) is higher than 2000

(4) Thurman EM, Organic Geochemistry of Natural Waters. 1985, Springer