3-dimethylaminopropan-1-ol

Endpoint summary

Additional information

The most sensitive organism regarding exposure to DMPA are aquatic algae (marine: ErC50 (72 h) = 16 mg/L; freshwater: ErC50 (72 h) >100 to < 250 mg/L), whereas fish and Daphnia magna were less sensitive to the substance (Fish: LC50 (96 h) = 147 mg/L; Daphnids: EC50 (48 h) = 112 mg/L).

Remarks:

- With regard to the LC/EC50, the effect values show a significantly higher toxicity related to non-neutralised test solutions; therefore, the observed toxicity is partly due to the pH induced by the substance. For risk assessment the effect data for the neutralised test medium should be used, since the quantities of DMPA that would be found in natural waters are not likely to affect the pH to a relevant extent. It is likely that the EC50 value from the test without neutralisation overestimates the potential toxicity of the target item.

- In several studies, the test item concentrations were not analytically verified, but are assumed to be stable, due to the the low n-octanol/water partition coefficient (log Kow = -0.23 at 25°C, pH 10.7; log Kow = -2.59 at 25°C, pH 7.2 ), the high water solubility (WS = 1.0E+06 mg/L at 20 °C), the moderate vapour pressure (VP = 1.56 hPa at 20 °C) and the low Henry´s law constant (HLC, uncharged: 0.016 Pa*m³/mol) of the substance.

Short-term toxicity to fish:

With high probability acutely not harmful to fish.

One toxicity test with fish is available for 3 -dimethylaminopropanol. In a static system established according to DIN 38412 part 15 testing the toxicity of the substance to Leuciscus idus the determined LC50 was 147 mg/L (geom. mean) after 96 hours (BASF AG, 1989). However, the observed results are probably due to changes in pH values caused by 1-(dimethylamino)propan-2-ol. The mortality in the pH-adjusted sample of 1000 mg/L was significantly reduced compared to the not-adjusted test solution. While the fish died immediately after exposure in the highest test solution of 1000 mg/L, the pH-adjusted solution of this concentration level showed a mortality of 50% after 96 h with the fish dieing after 24 h. The test concentrations were not analytically verified, but are assumed to be stable over the test period.

Long-term toxicity to fish:

In Annex IX of Regulation (EC) No 1907/2006, it is laid down that long-term toxicity testing in fish shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on fish. According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or CLP-Regulation (EC) No 1272/2008 or is assessed to be a PBT or vPvB. The hazard assessment of 3 -dimethylaminopropan-1-ol reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment. Therefore, a long-term toxicity testing in fish is not provided.

Short-term toxicity to aquatic invertebrates:

With high probability acutely not harmful to aquatic invertebrates.

The acute toxicity of 3 -dimethylpropanol (CAS 3179 -63 -3) to aquatic invertebrates was tested according to German Industrial Standard DIN 38412, Part 11 in two studies. The EC50 was determined to be greater than 100 mg/L (112 and 166 mg/L; BASF AG, 1989; report no. 89/1347 - Massenzucht and report no. 8971347 - Einzelzucht). The effect of the substance on the mobility of D. magna is probably in part due to pH changes caused by the substance. In both studies a neutralised sample of the highest concentration (320 and 580 mg/L) was tested in parallel. The toxicity of the test item was reduced. At 500 mg/L, the effects were delayed in time as all daphnids were immobilised in the neutralised 580 mg/L sample after 48 h while in the not-neutralised sample the daphnids were immobilised already after 3 h. At 320 mg/L, the toxicity was reduced to 45% after 48 h compared to 100% in the not-neutralised sample. The test item concentrations were not analytically verified, but are assumed to be stable. .

Long-term toxicity to aquatic invertebrates:

In Annex IX of Regulation (EC) No 1907/2006, it is laid down that long-term toxicity testing in aquatic invertebrates shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on fish. According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or CLP-Regulation (EC) No 1272/2008 or is assessed to be a PBT or vPvB. The hazard assessment of 3-dimethylaminopropan-1-ol reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment. Therefore, a long-term toxicity testing in aquatic invertebrates is not provided.

Toxicity to aquatic algae and plants:

Acutely harmful to aquatic algae.

In a study following German Industrial Standard DIN 38412, Part 9, the toxicity of DMPA to Desmodesmussubspicatus was investigated. The ErC50 (72 h) was determined to be 51.8 mg/L under not neutralised test conditions (BASF AG, 1989; report no. 89/1743). The inhibition of algal growth by 3 -dimethylaminopropanol was reduced by adjusting the pH in the test system. Toxic effects of the test substance are probably in part due to an increase in pH at high concentrations of the test substance. The highest concentration of 250 mg/L caused a reduced toxicity of 70% regarding the growth rate compared to 100% of the not-neutralised sample (72-h exposure; biomass: 67% compared to 97%). Based on this information a 72 -h ErC50 of >100 and < 250 mg/L was extrapolated for neutralised conditions.

In a test with marine algae (Skeletonema costatum, the 72 -h ErC50 was determined to be 16 mg/L (Eide-Haugmo et al., 2009/2012).

Toxicity to microorganisms:

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriately low concentrations.

One study on the toxicity of 1-(dimethylamino)propan-2-ol to microorganisms is available. In a guideline study conducted in compliance with OECD 209 an EC20 of > 1000 mg/L was determined after 30 minutes (BASF AG, 2005; report no. 08G0408/053146).