Quaternary ammonium compounds, dicoco alkyldimethyl, nitrites

PBT assessment

PBT assessment: overall result

Reference

Name:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

Reference substance:

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, nitrites

PBT status:

the substance is not PBT / vPvB

Justification:

P/vP

The substance is regarded to be P and NOT vP. The substance is not regarded as readily biodegradable in an OECD 301B study although one replciate sample of three showed up to 25% biodegradation in 28d. The substance therefore, maybe inherently biodegradable.

The substance is regarded to be NOT P and NOT vP based upon the available data on the structurally related tetraalkyl ammonium chlorides :-

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides & Dimethyldioctadecylammonium  chloride. It is deemed appropriate to read across from such analogous substances since once the quaternary ammmonium nitite is in solution under environmental conditions then the ions will be dissociated.

Quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides; CAS Number 68391-05-9; EC Number 269-924-1

OECD 301B, 61% biodegradation was observed in 28 days.

Dimethyldioctadecylammonium  chloride; CAS Number 107-64-2; EC Number 203-508-2

The EU Risk Assessment report for this substance (2009) reports that an OECD 301D study (1991) resulted in degradation of < 20% after 180 days and > 65% only after 280 days. A modified closed bottle test was used to compare the biodegradability of Dimethyldioctadecylammonium chloride (DODMAC) and Bis (hydrogenated tallow alkyl) dimethyl, chlorides (DHTDMAC). The degradation of DODMAC was ca. 36% and that of DHTDMAC was ca. 19% of the theoretical BOD after 20 days. The SIDS for Dimethyldioctadecylammonium chloride (DODMAC) reports two OECD 301D studies resulting in 43% and 4% degradation respectively after 28 days.

The nitrite ion is a component of the nitrogen cycle. In the environment, bacteria of the genus Notribacter oxidise nitrites to nitrates. Nitrates are reduced to nitrogen by anaerobic bacteria present in soil and sediment.

B/vB

The Screening Information Data Set Report (SIDS) for Dimethyldioctadecylammonium chloride reports two tests on Lepomis macrochirus. After 49 days BCFs of 13 and 32 respectfully in the whole body and 94 and 260 respectively in the guts were estimated. Ths indicates that there is moderate to high bioaccumulation potential. HOwever, not sufficiently high to result in the substance becoming a B (BCF > 2000) or a vB (> 5000).

According to Madsen et al 2001, The bioconcentration of DADMAC has been investigated in studies with bluegill sunfish (Lepomis macrochirus) and fathead minnow (Pimephales promelas) using radiolabelled 14C compounds. The radiolabelling technique does not allow a distinction between the parent compound and their metabolites formed and, hence, the term concentration ratio (CR) was used instead of BCF which normally refers to the intact parent compound. The CR was determined to 32 for C(16-18)2 DADMAC (Lepomis macrochirus) and 104 for C(18)2 DADMAC (Pimephales promelas) (Tolls et al. 1994). These results can be reliably read-across to the registered substance and suggest low potential for bioaccumulation.

In addition, Bioaccumulation Estimates (BCFBAF v3.01):

Log BCF from regression-based method = 1.850 (BCF = 70.79 L/kg wet-wt)

Log Biotransformation Half-life (HL) = 2.6765 days (HL = 474.8 days)

Log BCF Arnot-Gobas method (upper trophic) = 0.013 (BCF = 1.03)

Log BAF Arnot-Gobas method (upper trophic) = 2.759 (BAF = 574.3)

log Kow used: 12.52 (estimated)

Furthermore, the estimated BCF for sodium nitrite is 3.162 (EPI Suite v3.12 [SIDS report]) indicating negligible potential for bioaccumulation.

T

The Screening Information DataSet Report (SIDS) for Dimethyldioctadecylammonium chloride reports a number of short term studies on aquatic toxicity to fish. The lowest observed results were LC50 (48h) 0.1 - 0.37 mg/l. The lowest daphnia toxicity EC50 (48h) reported in the SIDS dossier is 0.36 mg/l and the lowest algae toxicity EC50 reported is 0.026 mg/l and a NOEC of 0.006 mg/l. This indicates aquatic toxicity effects. However, since the substance does not meet the criteria for P/vP or B/vB it cannot be regarded as a PBT.

The reported LC50 (96h) value for fish toxicity for Quaternary ammonium compounds, di-C12-18-alkyldimethyl, chlorides is 0.23 mg/l; NOEC 0.23 mg/l. Other key studies reported in the disseminated REACH registration dossier do not report lower values than this. The LC50 (48h) for daphnia toxicity is reported to be 0.295 mg/l (NOEC 0.1 mg/l) and for alage the EC50s (72h) are reported to be 0.386 mg/l and 0.148 mg/l (NOEC 0.06 mg/l).

As regards sodium nitrite a large number of reliable acute toxicity studies for fish are reported in the literature (Table 8 of the SIDS Report). The LC50 values reported vary widely dependent upon the species tested. The lowest LC50 reported is 0.54 mg/L and the highest is 1010.4 mg/L. The large differences observed are attributed to the ability of certain species tp prevent nitrite from crossing the gill membrane and entering the blood whilst other species concentrate nitrite in their blood. Even the lowest observed LC50 does not render the substance as Toxic ("T").

Reliable data on the acute toxicity of sodium nitrite to invertebrates are summarised in Table 9 of the SIDS Report. As with fish there is variation in toxicity between species. The lowest LC50 reported is 4.93 mg/L and the highest is 1200 mg/L. The lowest value would not classify the substance as Toxic ("T").

One reliable study is reported in the SIDS Report for sodium nitrite as regards toxicity to algae. The NOEC was 100 mg/L (OECD 201).