N,N,N-tri-C8-C10-alkyl-N-methyl-1-aminium sulfate

Endpoint summary

Additional information

Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates is poorly soluble in water and is strongly adsorbed to negatively charged surfaces such as suspended matter, vessels or organic material (including dissolved organic matter such as humic acids). Standard guideline studies and guidance documents are not fully appropriate to test cationic surface-active substances like the di/trialkylquats as these apply rather to normal hydrophobic chemicals, and do not take into account the low bioavailability of di/trialkylquats under environmental conditions. Aquatic ecotoxicity tests performed in river water are therefore considered to assess the aquatic environmental risk more realistically for quaternary ammonium compounds as the use of river water in the effect assessment compensates for the missing prediction of the bioavailability in the exposure assessment. Aquatic ecotoxicity tests performed in river water are therefore considered as higher tier tests when compared to aquatic ecotoxicity tests performed in reconstituted lab water. Aquatic ecotoxicity tests performed in river water were therefore selected to allow a PECaquatic, bulk/PNECaquatic, bulk approach. This is considered to be conservative but more environmentally realistic than the standard method. This approach is thus based on PEC estimations representing "total aquatic concentrations". To characterize the risk to the aquatic compartment the PECaquatic, bulk is compared with the PNECaquatic, bulk derived from river water ecotoxicity studies (ECETOC, 2003).

Experimental data on short-term toxicity to fish, to aquatic invertebrates and toxicity to algae are available for the target substance. No experimental data on long-term toxicity to fish, or long-term toxicity to aquatic invertebrates are available.

 

Short-term toxicity to fish:

The acute toxicity of the test item to fish (zebrafish) was determined according to the principles of the OECD-Guideline for Testing of Chemicals No. 203 (2019) from 2020-02-10 to 2020-02-14.

The test item is a slightly yellow solid and dispersible in water. A stock solution with a nominal concentration level of 100 mg test item/L was freshly prepared with dilution water. Out of the stock solution a concentration of 31.3 µg/L was tested in a limit test. The selection of the test concentration is based on the derivation of a threshold concentration (TC) from the results of an alga toxicity test (ErC50 (0-72 h) = 99.0 µg/L (geometric mean measured test item test item concentration)) and a daphnia acute immobilization test (EC50 (0-48 h) = 31.3 µg/L (geometric mean measured test item concentration)).

The study was performed over a period of 96 hours under semi-static conditions with renewal of test solutions after every 24 hours as a worst-case exposure. Seven test organisms were exposed to the limit concentration and the control, respectively. Water quality parameters (temperature, pH-value and oxygen-saturation) measured at 0, 24, 48, 72 and 96 hours were determined to be within the acceptable limits. The test media was visually clear

The concentration of the test item was analytically verified via LC-MS/MS in the fresh media at the start of the exposure and at one renewal interval (0 hours and 72 hours) and in the corresponding 24-hours aged media after 24 and 96 hours in the limit test item concentration and the control. The measured concentrations of the test item at the start of two exposure intervals after 0 and 72 hours were between 74 and 94% of the nominal values. At the end of the exposure intervals after 24 and 96 hours the measured concentrations of the test item were between 18 and 80%, the decrease over 24 hours was < 20% with one exception. All effect values were based on the geometric mean measured concentration of the test item.

All validity criteria of the test guideline were met. The test item does not show toxic effects on fish at the limit concentration of 17.7 µg/L. 

 

Short-term toxicity to aquatic invertebrates:

The 48-h-acute toxicity of Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates to Daphnia magna was studied under static conditions according to OECD Guideline 202 (2004).  Daphnids were exposed to control and test chemical at 5 concentrations (1.41, 2.91, 5.21, 13.4, 32.3 mg/L) in natural river water for 48 h. Mortality/immobilization was observed daily. 

The 48 hours-EC50 for Daphnia magna was 31.3 µg/L (95% confidence limits: 6.85 – > 32.3 µg/L) for the test item.

   

Toxicity to algae and cyanobacteria:

In a 72 hour toxicity study according to OECD Guideline 201 (2011), the cultures of Pseudokirchneriella subcapitata HINDÁK, CCAP 278/4 (axenic) were exposed to Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates at concentrations of 0.0313 – 0.0625 – 0.125 – 0.250 – 0.500 mg/L in natural river water under static conditions.

72 h NOEL of Quarternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates to the green alga Pseudokirchneriella subcapitata based on growth rate and yield inhibition are 0.0209 mg/l based on geometric mean measured test item concentration.

ErC10 was 0.0445 mg/L, ErC50 was 0.099 mg/L, EyC10 was 0.0264 mg/L, EyC50 was 0.0487 mg/L based on geometric mean measured test item concentration.

 

Toxicity to microorganisms:

In a 3 hour toxicity study conducted according to OECD Guideline 209 (2010), the cultures of activated sludge of a predominantly domestic sewage treatment plant were exposed to Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates at nominal concentrations of 0 (control), 1, 3.16, 10, 31.6, and 100 mg a.i./L mg/L under static conditions.

The batch of activated sludge was checked for sensitivity by testing the reference substance Copper (II) sulphate pentahydrate.

The respiration rates of the control, reference and test item replicates were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the controI respiration rates. The mean inhibition of respiration for the test item replicates ranged from -1% to 87%

The 3 h NOEC of C12-18 Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates is 3.16 mg a.i./L. The 3 h EC10 is 6.34 mg a.i./L, and the EC50 is 26.1 mg a.i./L.

 

In addition, long-term toxicity data obtained with the source substance DDAC are used for chemical safety assessment. A justification for read-across is attached to Iuclid section 13.

 

Long-term toxicity to fish:

In a fish early life stage test the NOEC for DDAC in Zebra fish was determined to be 312.5 µg/L, the NOEC in Medaka was 1250 µg/L.

 

Long-term toxicity to aquatic invertebrates:

In this Daphnia reproduction test the NOEC for DDAC in Daphnia magna was determined to be 125 µg/L.

 

 

Conclusion:

The most sensitive species in the chronic/reproduction tests was algae. The EC10 of the target substance Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates was 44.5 µg/L. This value is used to derive the PNECs.

The substance is not readily biodegradable. The measured BCF for the closely related substance DODMAC is 13 L/kg and therefore the bioconcentration potential is very low. The bioaccumulation criterion (BCF >= 100 L/kg) is not fulfilled.

Therefore. based on the results above Quaternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates is classified as Aquatic acute category 1 (M-factor 10) and Aquatic chronic category 1 (M-factor 1).