Propanoic acid, 2-hydroxy-, ammonium salt (1:1), (2S)-

Endpoint summary

Description of key information

Ammonium-(S)-lactate is a colourless solid organic salt, having a melting point of 92 °C and a boiling point of 185 °C. As pure ammonium-(S)-lactate is very difficult to isolate, due to the substance’s strong hygroscopic properties, the relative density is only reported for a highly concentrated (70% w/w) aqueous solution, corresponding to the substance as actually placed on the market. The value is 1.16 and is derived by read across from the respective aqueous ammonium lactate (rac) solution (chirality has no influence on this physical-chemical property). The vapour pressure of pure ammonium-(S)-lactate was determined according to OECD guideline 104. As the test material started to decompose at 135 °C, the vapour pressure was calculated in a temperature range between 60 °C and 120 °C. At 20 °C, the substance ammonium-(S)-lactate has a vapour pressure of 0.61 Pa. The ionic compound has a water solubility of approximately 1077 g/L, which is derived by read across from its racemic counterpart, ammonium lactate (rac) (chirality has no or only minor influence on this physical-chemical property). The corresponding partition coefficient octanol-water, estimated by QSAR, is -3.84 and reflects the high water solubility. The dissociation constant in water has been determined to 9.21.