N-[3-(dimethylamino)propyl]docosanamide

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

1.16 µg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

11.6 µg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.116 µg/L

Assessment factor:

10 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

1.081 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

41 µg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

4.1 µg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

7.52 µg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Ecotoxicity studies with DIMAPDO did not show acute toxicity values < 1 mg/L.

short-term toxicity to aquatic organisms

Fish: LC50(96 h) = 5.54 mg/L

Invertebrate: EC50(48 h) = 1.16 mg/L

Algae or aquatic plants: ErC50= 1.73 mg/L

Biodegradation in water: Readily biodegradable

logKow: 2.85 (calculated)

 

Relevant data used for calculation of PNECs

All available aquatic toxicity studies were performed with DIMAPDO lactate. DIMAPDO lactate is an ionic chemical compound that dissociates in water under neutral pH conditions almost entirely into DIMAPDO and lactate. This is supported by the observation that at the start of the exposures the test solutions were usually clear and but within the first 24 hours the test solutions became cloudy dispersed solutions. DIMAPDO lactate with its good water solubility dissociates over time into the highly soluble lactate and the only slightly soluble DIMAPDO that forms small micelles in aqueous solutions. Therefore aquatic organisms are mainly exposed to DIMAPDO and lactate and not to DIMAPDO lactate.

Lactate is a normal metabolic intermediate produced and needed by most mammalian cells and micro-organisms and has a low aquatic toxicity (registered substances databank ECHA website). Therefore all toxic effects seen can be attributed to DIMAPDO.

Bowmer et al. published in 1998 a study where they compared the ecotoxicity of lactic acid and its alkyl esters experimentally with the micro alga Selenastrum capricornutum, the crustacean Daphnia magna and the fish species Danio rerio and Pimephales promelas. The results presented indicate that alkyl lactate esters show some differences in their ecotoxicity when compared to non polar narcotic compounds but that these differences are generally small. For example for octyl lactate the EbC50 for algae (72-96h) was 7.6 mg/L, the daphnia EC50 (48 h) was 41 mg/L and the fish LC50 (96 h) was 24 mg/L. These values are relatively similar to the values of octanol with an EbC50 for algae (72-96h) of 14.6 mg/L, a daphnia EC50 (48 h) of 31.8 mg/L and a fish LC50 (96 h) of 14 mg/L (registered substances database ECHA website).

 

CONCLUSION:

Therefore under environmental conditions it is toxicologically not relevant if DIMAPDO or DIMAPDO lactate are introduced in an aquatic medium.

 

References:

C.T. Bowmer, R.N. Hooftman, A.O. Hanstveit, P.W.M. Venderbosch & N. van der Hoeven. The ecotoxicity and the biodegradability of lactic acid, alkyl lactate esters and lactate salts. Chemosphere, Vol. 37, No. 7, pp. 1317-1333, 1998

Conclusion on classification

The most sensitive organism to DIMAPDO was Daphnia magna. Thus, the lowest acute toxicity value is the 48 h EC50 to Daphnia magna of 1.16 mg/L. This value is used for the calculation of PNECs.

Based on the 72 h NOEC of 0.36 mg/L for algae, its readily biodegradability and low potential for bioaccumulation (log Kow < 3) DIMAPDO has to be classified as Aquatic Chronic 3 in accordance with CLP Regulation (EC) No 1272/2008.