2-aminoethanol

Endpoint summary

Additional information

Acute toxicity to fish

The effect of monoethanolamine on several fish species including rainbow trout (Oncorhynchus mykiss), fathead minnow (Pimephales promelas), goldfish (Carassius auratus), common carp (Cyprinus carpio), and medaka (Oryzias latipes) has been investigated. Test concentrations were analytically verified in most studies (PTAC, 2006; Huels, 1997, NITE, 1997; Geiger, 1990, Bridie, 1979). With the exception of very high concentrations (>1000 mg/L), the measured concentrations were within acceptable limits (±20% of nominal).

The LC50 values for 96-hour exposure range from > 100 mg/L for medaka to 2070 mg/l for fathead minnow. Studies in which the pH was measured indicate that the test material increased pH to approximately 10.1 – 10.2 in some studies. Studies performed in goldfish show that the LC50 value of monoethanolamine increases dramatically if the pH is neutralized, suggesting that the studies with lower LC50 values may have been influenced by high pH.

The lowest effect value was determined in a guideline study (Environment Canada EPS 1/RM/9, 1990/1996) with Oncorhynchus mykiss as test species. The fish were exposed to a series of 5 test concentrations and a control in a static approach. The 96 -h LC50 was 105 mg/L (nominal, analytically verified). The test solutions were not pH adjusted (PTAC, 2006).

It can be concluded that 2 -aminoethanol is with high probability not acutely harmful to fish.

Long-term toxicity to fish

The long-term effects of MEA (CAS 141 -43 -5) were studied in an early lifestage test according to OECD 210 performed by the Ministry of the Environment in Japan (NITE, 2008). Oryzias latipes was used as the test species. The fish (eggs) were exposed in a flow-through system. The test concentrations were analytically verified and showed to be stable over the exposure period. The 41-d NOEC was 1.24 mg/L (measured).

This result is supported by a prolonged fish test with Oryzias latipes conducted according to OECD 204 (NITE, 1997). The 14-d NOEC (mortality) was > 100 mg/L (measured).

Mayer et al. (1986) determined the 100-d NOEC for reproduction, percent hatch and percent viability of Salvelinus fontinalisto be 1.77 mg/L. The 100 -d NOEC for survival, length, weight of this species was > 20 mg/L. Test concentrations were not analytically verified, however, the test was performed with a flow-through system and tests with chemical analysis showed an acceptable recovery of the test item in the test solutions. In addition, the substance is highly water soluble, is not expected to evaporate rapidly into the atmosphere (Henry's law constant < 1 Pa*m³/mol) and adsorption is also not expected.

Based on the available effect data long-term effects are not to be expected.

Acute toxicity to aquatic invertebrates

The acute toxicity to aquatic invertebrates was tested in several studies. The key study investigating the immobilisation of Daphnia magna was conducted according to OECD 202 and ASTME-729 (P&G, 2012). The study was conducted under GLP and with analytical monitoring. The 48 -h EC50 was determined to be 27.04 mg/L (geometric mean). This value indicates that 2 -aminoethanol is acutely harmful to aquatic invertebrates.

Further studies support this conclusion:

In an acute immobilization study according to EU method C.2 under static conditions with analytical monitoring the immobilization of Daphnia magna was investigated. The 48 -h EC50 was determined to be 65 mg/L (measured; Huels, 1997). In a semi-static Daphnia magna immobilisation test according to OECD 202 and under GLP with analytical monitoring, the 48 -h EC50 was 97.26 mg/L (nominal, analytically verified; NITE, 1997). In a further study with Daphnia magna, the 48 -h EC50 was determined to be 32.6 mg/L. However, the test was performed according to a lab procedure which was not further specified in the report. Information on test performance and analytical monitoring are lacking (UCC, 1988).

The effect of MEA on Daphnia magna was studied according to an Environment Canada method (PTAC, 2006). Neonates were exposed to a series of 5 test concentrations and observed over 48 h (mortality). The test concentrations were analytically verified. The 48-h LC50 was determined to be 66.7 mg/L (95% CL: 60.1 -74.1 mg/L; nominal). 

Libralato et al. (2010) tested a saline species (Artemia franciscana). The 24 -h EC50 was determined to be 43 mg/L and is within the same range as the freshwater data for 2 -aminoethanol.

The effect of MEA on Hyalella azteca was studied according to an Environment Canada method (PTAC, 2006). 50 animals were exposed to a series of 5 test concentrations and observed over 96 h and dead neonates counted after 48 and 96 h. The test concentrations were analytically verified. The 96 -h LC50 was determined to be 170 mg/L (95% CL: 163 -177 mg/L; nominal).

Based on the available data, 2 -aminoethanol is acutely harmful to aquatic invertebrates.

Long-term toxicity to aquatic invertebrates

The long-term effects on aquatic invertebrates were assessed in a 21-day chronic reproduction test onDaphnia magna, according to OECD guideline 202, part 2 under GLP conditions (NITE 1996, 1997). The test concentrations were analytically verified. The 21 -d NOEC was determined to be 0.85 mg/L (time-weighted average).

Long-term effects to Daphnia magna are expected (21 -d NOEC = 0.85 mg/L)

Toxicity to algae

The key study was performed by NITE (1997). The test followed OECD 201 and used Pseudokirchneriella subcapitata as test species. The test concentrations were analytically verified, but the effect concentrations are based on nominal values since the measured concentrations remained between 84 and 109% of the nominal test concentrations. The 72-h ErC50 was determined to be 2.80 mg/L, the 72 -h ErC10 was 0.7 mg/L.

The key study is supported by a GLP study conducted by Huels (1997) following the EU method C.3. The test species was Desmodesmus subspicatus. The 72-h ErC50 was 22 mg/L, the 72-h ErC10 was 8.5 mg/L (measured).

Marine algae were tested by Libralato et al. (2010) according to ISO 10253. The test species was Phaeodactylum tricornutum. The concentration of the test item was analytically verified in the stock solution. Five test concentrations in a geometric series with a factor of 2 plus one control were used to determine the effect of MEA on marine algae. After 72 h of exposure an EC50 of 24.7 mg/L and a NOEC of < 6 mg/L were determined.

In addition, Eide-Haugmo et al. (2012/2009) performed a guideline study according to ISO 10253 with the marine algae Skeletonema costatum. After 72 hours an ErC50 of 198 mg/L was determined.

For algae exposed to monoethanolamine for 7-8 days, the toxicity threshold is approximately 0.8 mg/l. Neutralization had no significant effect on the 8-day toxicity threshold of monoethanolamine in Scenedesmus quadricauda (Bringmann & Kuehn, 1977 -1980). This value should not be used for risk assessment since this study was not performed according to a guideline and a valid guideline study with analytical monitoring is available.

In conclusion, 2- Aminoethanol is acutely toxic to algae (72 -h ErC50 = 2.8 mg/L).

Long-term effects to aquatic algae are expected (72 -h ErC10 = 0.7 mg/L).