Registration Dossier
Registration Dossier
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EC number: 201-196-2 | CAS number: 79-33-4
Water solubility
Administrative data
Link to relevant study record(s)
- Endpoint:
- water solubility
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 2007
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Company data with limited reporting
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- Generating saturated solutions at a range of temperatures, and measuring the resultant dissolved concentration.
- GLP compliance:
- no
- Type of method:
- flask method
- Specific details on test material used for the study:
- Pure lactic acid
- Key result
- Water solubility:
- 86.1 other: % w/w
- Temp.:
- 20 °C
- pH:
- >= 0 - <= 14
- Remarks on result:
- other: Lactic acid is soluble in water in all ratios. Solubility is not dependent on pH. pH of the solution will depend on the concentration, but at higher concentrations an ever larger fraction of the lactic acid will form oligomers.
- Water solubility:
- 93 other: % w/w
- Temp.:
- 35 °C
- pH:
- >= 0 - <= 14
- Remarks on result:
- other: Lactic acid is soluble in water in all ratios. Solubility is not dependent on pH. pH of the solution will depend on the concentration, but at higher concentrations an ever larger fraction of the lactic acid will form oligomers.
- Details on results:
- Stable: yes
pKa: 3.85 at 25 °C
Temperature effects: Solubility 76.0 % at 0 °C; 81.3 % at 10 °C; 95.1 % at 40 °C.
Degradation products: no - Conclusions:
- Aqueous solubility of lactic acid is 86% w/w at 20 °C. At 35 °C, solubility is 93%. Apparently the viscosity of the solution is such that upon cooling, no lactic acid crystallizes from a 93% solution, but all lactic acid remains in a supercooled solution state.
- Executive summary:
L-(+)-lactic acid is miscible with water up to a content of 86 - 93%, dependent on the temperature.
Reference
Description of key information
L-(+)-lactic acid is freely miscible with water: Concentrations of up to 86% (w/w) result in a clear solution.
Key value for chemical safety assessment
- Water solubility:
- 860 g/L
- at the temperature of:
- 20 °C
Additional information
Aqueous solubility of lactic acid is 86% w/w at 20 °C. At 35 °C, solubility is 93 %. Apparently the viscosity of the solution is such that upon cooling, no lactic acid crystallizes from a 93% solution, but all lactic acid remains in a supercooled solution state.
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