Amides, C16-18, N-[3-(dimethylamino)propyl]

Long-term toxicity to fish

Description of key information

9 d-NOEC(behaviour) = 0.1 mg/L (OECD guideline 212, GLP, RL1);  read across from Stearic acid 3-(dimethylaminopropyl)amide

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.1 mg/L

Additional information

No experimental data are available for C16-18 DMAPA amidoamine. However, a chronic toxicity study with the read-across substance Stearic acid 3-(dimethylaminopropyl)amide is available. For justification for read-across see endpoint summary "Aquatic toxicity".

 

The effects of the test item to the embryo and sac-fry stages of the zebrafish (Danio rerio) were determined according to OECD Guideline 212. A semi-static test procedure with natural river water and daily renewal of the test media was performed with the nominal test item concentrations of 0.100 – 0.316 – 1.00 – 3.16 – 10.0 mg/L.

The test was started by placing fertilized eggs in the test vessels and lasted 9 days (5 days post-hatch). 30 eggs of Danio rerio were exposed per test concentration and control (3 replicates with 10 eggs each), respectively.

On day four 93 % of the control larvae have hatched. Therefore, study day 4 was defined as post hatch day 0 (PHD 0).

Different toxic endpoints were determined: egg hatch, time to hatch, post hatch survival, overall fry survival and mortality, fry growth (expressed as length and weight), morphological and behavioural effects. The results of the named parameters were checked for statistically significant differences. The NOEC, LOEC and LC-values were determined based on the statistical results.

Stearic acid 3-(dimethylaminopropyl)amide is a tertiary straight chain amine. The test item had a low water solubility and sorbed to organic and inorganic materials by different mechanisms. The sorption processes are mostly non-linear, means are concentration dependent. Due to these properties the test item was difficult to test in artificial water (e.g. sorption to the test organism and walls of the test vessel). Natural river water contained particulate as well as dissolved organic carbon to which the test item could sorb partially preventing that the test item settled onto surfaces. The sorbed fraction of the test item was difficult to extract from the test system which normally led to low analytical recoveries. Nevertheless the test item was present in the test system and therefore available for exposure (dissolved in water and sorbed). Sorption of the test item to the glass ware of the test system was monitored as appropriate. Due to the properties of the test item nominal concentrations were used instead of measured ones.

All concentrations of the test item and the control were analytically verified by LC-MS/MS at the start and the end of three exposure intervals.

 

NOEC, LOEC: Hatch, Fry Survival, Growth, Behaviour based on nominal test item concentrations [mg/L] of the read-across substance Stearic acid 3-(dimethylaminopropyl) amide

 

Parameter	NOEC [mg/L]	LOEC [mg/L]
Hatch	1.00	3.16
Post hatch survival	0.316	1.00
Overall survival	0.316	1.00
Length	0.316	1.00
Weight	0.316	1.00
Abnormal behaviour (Quiescence, Remaining unusually long at the bottom)	0.100	0.316

 

The following study showing similar results with C20/22 ATQ is enclosed to justify the read-across approach for sediment and terrestrial toxicity studies.

 

The effects of the test item C20/22 ATQ to the embryo and sac-fry stages of fish (Zebrafish /Danio rerio) were determined according to OECD Guideline 212.

A semi-static test procedure with renewal of the test media in 48 h intervals was performed with the nominal concentrations of 0.032 - 0.100 - 0.320 - 1.00 - 3.20 mg/L, corresponding to geometric mean measured concentrations of 0.0246 – 0.0753 – 0.243 – 0.762 – 1.62 mg/L.

The test was started by placing fertilized eggs in the test vessels and lasted 9 days (5 days post-hatch). 30 eggs of Danio rerio were exposed to the test concentrations and the control (3 replicates with 10 eggs each).

On day four 90 % of the control larvae had hatched. Therefore, study day 4 had been defined as post hatch day 0 (= PHD 0).

Different toxic endpoints have been determined: egg hatch, time to hatch, fry growth (expressed as length and weight), morphological and behavioural effects, post hatch survival, overall fry survival and mortality, respectively. The results of the named parameters were checked for statistically significant differences. The NOEC, LOEC and LC-values were determined based on the statistical results. The revealing results are summarized in Table 1 and Table 2.

The concentration of the test item and control were analytically verified via LC-MS/MS from freshly prepared media on days 0, 4 and 8 and from 48 hours old media on days 2, 6 and 9.

The test item has a low water solubility and sorbs to organic and inorganic materials by different mechanisms. The sorption processes are mostly non-linear, means are concentration dependent. Due to these properties the test item is difficult to test in synthetic water (e.g. sorption to the test organism and walls of the test vessel) and results from such tests depend from the test settings applied. Using natural river water which contains particulate as well as dissolved organic carbon to which the test item can sorb partially reduces the difficulties encountered in tests with synthetic water e.g. preventing that the test item settles onto surfaces. The sorbed fraction of the test item is difficult to extract from the test system which normally leads to low analytical recoveries. Due to the short exposure period these low recoveries cannot be associated to biodegradation. This means the test substance is present in the test system and therefore available for exposure (dissolved in water and sorbed also called bulk). This so called Bulk Approach is described by ECETOC (2003). Due to the properties of the test item geometric mean measured concentrations have to be used.

Hatch, Growth, Fry survival: NOEC, LOEC based on geometric mean measured test item concentrations of C20/22 ATQ

 

Parameter	NOEC[mg/L]	LOEC[mg/L]
Hatch	0.762	1.62
Length	0.762	1.62
Weight	0.243	0.762
Post hatch survival	0.762	1.62
Overall survival	0.243	0.762
Overall NOEC and LOEC	0.243	0.762