Ethylamine

Endpoint summary

Additional information

Short-term toxicity to fish: With high probability acutely not harmful to fish.

Weight-of-evidence:

- 48-h LC50 = 168 mg A.I./L, Juhnke & Luedermann (1978). DIN 38412-15 (draft), Leuciscus idus:

- 48-h LC50 > 700 mg A.I./L, BASF AG, 1977, screening test, Leuciscus idus

- 48-h LC50 > 500 mg A.I./L, BASF AG, 1977, screening test, Leuciscus idus

- 96-h LC50 = 258 mg/L, QSAR Toolbox v4.3, the substance was within the applicability domain, BASF SE, 2019

The test concentrations were not analytically verified.

Long-term toxicity data to fish: no data available. Information requirement waived based on the results of the chemical safety assessment (no hazard, no PBT/vPvB; RCR < 1).

Short term toxicity to aquatic invertebrates: Acutely toxic to aquatic invertebrates.

Key study: - 48-h LC50 = 7.9 mg A.I./L, measured, Ceriodaphnia dubia, Arkema, rep. no.: 94-7-53333, 1994

Long-term toxicity to aquatic invertebrates:

Key study: 7-d NOEC 3.2 mg A.I./L, measured, Ceriodaphnia dubia, EPA Guideline 1002.0 (1989), Arkema, rep. no.: 94-7-5335, 1994 

Toxicity to aquatic algae and cyanobacteria: Acutely toxic to algae.

Key study: 8-d EC50 = 1.6 mg A.I./L, worst case, Scenedesmus quadricauda, pH-adjusted solutions, Bringmann and Kuehn, 1978

Supporting study: 96 EC3 = 10 mg/L, Scenedesmus quadricauda, nominal, test item purity not specified, Bringmann and Kuehn, 1959.

The test concentrations were not analytically verified.

Toxicity to aquatic microorganisms: Depending on local conditions and existing concentrations, disturbances in the biodegradation process of activated sludge are possible.

Key study: 16-h NOEC = 20.3 mg A.I./L, pH-adjusted solutions, DIN 38412-8, Pseudomonas putida, Bringmann and Kuehn, 1977

Conclusion: Based on the available experimental and estimated data for ethylamine, it can be concluded that the substance is considered to be acutely toxic to aquatic organisms.

However, ethylamine changes the pH in the test solutions and hence influence the effect on the test organisms. It could be demonstrated in the key studies provided for the assessment of short-term toxicity to algae and microorganisms, that adjusting the pH in the test solution reduced the adverse effects. For the risk assessment the effect data for the neutralized test medium should be used since the quantities of the substance that would be found in natural waters are not likely to affect the pH to a relevant extent. It is likely that the L(E)C-values from the tests without neutralization overestimate the potential toxicity of these matrices.

Ethylamine is characterized by a high vapor pressure (140000 Pa, measured, Daubert et. al.) and a high Henry’s Law Constant (1.25 Pa*m3/mol, calc. EPI Suite v 4.11, 2019). The substance has also a high water solubility (1E+06 mg/L, Gestis, 2009). However, the dissociation constant (pKa=10.41, SPARC On-Line Calculator, 2019) indicates that the substance will be present in its ionized form under environmentally relevant conditions (pH 4–9). Hence, the distribution of ethylamine into air may be overestimated. Moreover, the concentrations of ethylamine in the test solutions of a short- and a long-term toxicity study with Ceriodaphnia (IUCLID Ch. 6.1.3 and 6.1.7) were analytically monitored. Analysis of the exposure resulted in measured concentrations which were in agreement with the nominal concentrations over the 24-h exposure period. The deviation of the mean measured concentrations was less than 20% of the nominal values. The highest concentrations (1.7 – 13 mg A.I./L, nominal) showed a higher recovery rate (> 90%) than the lower concentration (0.22 – 0.85 mg A.I/L; 84 – 88% of nominal). According to these measurements, it can be concluded that the concentration of monoethylamine at the highest treatment levels (>1.7 mg A.I./L) is generally stable between the 24-hour renewal periods.

In the screening acute toxicity tests with fish, no mortality was observed at the highest concentrations (48 h, LC50 > 100 mg A.I./L, see IUCLID Chapter 6.1.1.). Since the tested concentrations of ethylamine in these studies were clearly higher than 13 mg A.I./L and the substance is ionized under the environmentally relevant conditions, it can be assumed that the test concentrations were sufficiently stable over the 48-h exposure period to establish the acute toxicity of monoethylamine to aquatic organisms.