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There is few information available about N-benzyl-N-C16-18 (even numbered)-alkyl-N-methyl-C16-18 (even numbered)-alkyl-1-aminium chloride. Nevertheless analogy can be made with N-C16-C18(even numbered)-alkyl-N,N-dimethyl-C16-C18(even numbered)-alkyl-1-aminium chloride (DHTDMAC – CAS: 92129-33-4 or 61789-80-8 or 68002-59-5) as the only one difference between the 2 substances is the presence/absence of benzyl group which is not supposed to impact environmental fate and pathways of the substance.

Therefore for covering missing information,

data are mainly read-acrossed from DHTDMAC (for which a European Risk Assessment Report prepared by German Authorities and published in 2002 is available). The conclusions of this review for the different compartments are summarized hereafter.

Degradation in Wastewater treatment plant (WWTP) and surface water (read-across from DHTDMAC)

A modified closed bottle test was used to compare the biodegradability of DODMAC and DHTDMAC by a mixture of preadapted soil bacteria (Clancy & Tanner, 1991). The degradation of DODMAC was approx. 36% and that of DHTDMAC was approx. 19% of the theoretical BOD after 20 days (1 mg/l test substance, 15 mg/L O2-content). When the inoculum was not adapted degradation was only 8% at 1 mg/L DHTDMAC and 35% at 0.4 mg/L.

In a SCAS test (OECD 303A) with doomestic sludge, DHTDMAC was eliminated to more than 95% after 45 days, measured as DOC reduction (Boutonnet, 1990). In a Zahn-Wellens-test (OECD 302B) with industrial activated sewage sludge, DHTDMAC was eliminated to more than 70% after 3 hours. Elimination reached 92 % after 15 days, measured as DOC reduction. A rate of biological degradation could not be determined (Hoechst, 1993a).

An OECD-confirmatory test was conducted with DHTDMAC and activated sludge from a domestic wastewater treatment plant (Hoechst, 1989d). The system was dosed with increasing concentrations of 0.5 -5 mg/L. Based on the concentration of disulfineblue active substance in the effluent of the test system the elimination was higher than 95% after 10 days.

The results of a continuous activated sludge test and a SCAS test are reported in ECETOC (1993). In the SCAS test 80 to 98% of 0.5 mg/L DSDMAC and DHTDMAC were adsorbed to the sludge after 7 days (Hopping, 1975). Production of 14CO2 could not be observed. In the CAS test 71.2% of 0.01 mg/L DSDMAC were adsorbed after 5 days (Shimp, 1992). Production of CO2

was not monitored.

Results for DODMAC and DHTDMAC degradation in batch activated sludge tests measuring 14CO2 production are cited in ECETOC 1993 (Brown, 1975). Degradation of DHTDMAC was better than DODMAC under the respective comparable conditions in every case (up to 89.8%, non-adapted, without LAS). Adaptation had no influence and increasing LAS concentrations had a slightly decreasing tendency.

In another river water die-away test primary degradation of DHTDMAC was assessed (Schneider & Levson, 1987). With an initial concentration of 8.25 mg/L 70% degradation were observed after 40 and 70 days. With a substance concentration of 0.5 mg/L primary degradation was almost the same with 75% after 40 and 55 days. Degradation started after 15 resp. 20 days. Therefore DHTDMAC is biodegradable.

It is shown in several tests that DHTDMAC is not readily biodegradable and there is no standard guideline test from which inherent biodegradability could be concluded.

Adaptation seems to be necessary for significant degradation but even then mineralisation is very slow. In river water tests with adapted inocula degradation is occurring with a half-life in the range of several weeks.

Most of the data referring to the elimination in wastewater treatment plants do not distinguish between biodegradation and adsorption. Therefore no degradation constant can be derived.

One study is available for N-benzyl-N-C16-18 (even numbered)-alkyl-N-methyl-C16-18 (even numbered)-alkyl-1-aminium chloride

and is summarized in the IUCLID.

The biodegradation potential of N-benzyl-N-C16-18 (even numbered) -alkyl-N-methyl-C16-18 (even numbered) -alkyl-1-aminium chloride has been assessed through an OECD 301F conducted under GLP conditions. Under the test conditions, the % of biodegradation of N-benzyl-N-C16-18 (even numbered) -alkyl-N-methyl-C16-18 (even numbered) -alkyl-1-aminium chloride reached a maximum of 13 % at day 14, and 0 % as an artefact at the end of the 28 day testing period. This was due to an increase in blank N-benzyl-N-C16-18 (even numbered) -alkyl-N-methyl-C16-18 (even numbered) -alkyl-1-aminium chloride is not readily biodegradable.

Nevertheless, simulation test results (302B and 303A) indicate that more than 95% of N-benzyl-N-C16-18 (even numbered) -alkyl-N-methyl-C16-18 (even numbered) -alkyl-1-aminium chloride would be eliminated further to conventional treatment procedures.

Degradation in soil (read-across from DHTDMAC)

Several references are available in order to characterize DHTDMAC behaviour in soil. DHTDMAC is considered to be stable in soil and the same conclusion applies to N-benzyl-N-C16-18 (even numbered) -alkyl-N-methyl-C16-18 (even numbered) -alkyl-1-aminium chloride.

Degradation in sediment (read-across from DHTDMAC)

For degradation in sediments simulation tests are lacking. Nevertheless, the available monitoring data reveal that biodegradation in environmental sediments is low. There is no hint that DHTDMAC can be degraded under anaerobic conditions and the same assumption is made for N-benzyl-N-C16-18 (even numbered) -alkyl-N-methyl-C16-18 (even numbered) -alkyl-1-aminium chloride.

Abiotic degradation

N-benzyl-N-C16-18 (even numbered)-alkyl-N-methyl-C16-18 (even numbered)-alkyl-1-aminium chloride is not expected to be degraded under environmental conditions based on its structure which does not contain any hydrolysable covalent bonds. Cleavage of a carbon-nitrogen bond under environmental conditions is only possible with a carbonyl group adjacent to the nitrogen atom. Degradation of N-benzyl-N-C16-18 (even numbered)-alkyl-N-methyl-C16-18 (even numbered)-alkyl-1-aminium chloride through hydrolysis is therefore not considered.

Phototransformation in air/soil/water and sediment are not required under REACH.

Bioaccumulation (read-across from DHTDMAC)

Lepomis macrochirus was exposed to 14C-DHTDMAC for 49 days in a continuous flow-through system in river water and laboratory water with mean concentrations in the test period of 18 μg/L and 16 μg/L respectively (no solvent carrier, Lewis & Wee, 1983). The river water was sampled at Town River, Massachusetts, and contained 2-84 mg/l suspended solids, 0.04-0.59 mg/L methylene blue active substances - MBAS and 10-15 mg/L disulfine blue active substances -DBAS (pH = 6.4-7.7, total hardness = 14-38 mg/L CaCO3). In river water BCFs of 13 L/kg in the whole body and 94 in the inedible tissue (viscera) were estimated based on measured concentrations. When laboratory water was used the respective BCFs were 32 and 256 L/kg. The ecological effects of the substance are strongly dependent on the test medium, differences are caused by adsorption onto suspended matter and complexation with anionics. Therefore, the relevant ecotoxicity values are derived from tests in river water.

In both waters DHTDMAC did not concentrate to a significant degree in edible tissue (BCF of the fillets < 5 L/kg). In a depuration phase in well water 93% of the accumulated radioactivity was eliminated from the inedible tissues after 14 days.

Therefore DHTDMAC is considered to be non bioaccumulative and the same conclusion applies to N-benzyl-N-C16-18 (even numbered)-alkyl-N-methyl-C16-18 (even numbered)-alkyl-1-aminium chloride.

Bioaccumulation in terrestrial organisms is not a formal REACH requirement.

Adsorption/desorption (read-across from DHTDMAC)

The determination of a Koc from log Kow is not opportune, because the common Koc derivations are not valid for surface active substances like DHTDMAC. DHTDMAC adsorbs onto both the mineral and the organic fraction of soil and sediments. Kappeler (1982) found that on average 27% of the DHTDMAC in river water is adsorbed onto suspended matter (mean 22 mg/L suspended solids). The Kpsusp is calculated to 16,800 L/kg from these values.

This demonstrates that DHTDMAC can be bound very strongly by some minerals, while in others relatively small distribution constants were estimated. Under environmental conditions, the sorption properties of DHTDMAC probably vary in a wide range depending on the nature of the adsorbant

and the same conclusion applies to

N-benzyl-N-C16-18 (even numbered)-alkyl-N-methyl-C16-18 (even numbered)-alkyl-1-aminium chloride

.