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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data from handbook or collection of data, subject to peer review and considered reliable.

Data source

Reference Type:
review article or handbook

Materials and methods

Principles of method if other than guideline:
Turbidity titration was stated for one test. No other methods or data were provided in the summary report. Sample purity and pH was not given.
GLP compliance:

Test material

Constituent 1
Reference substance name:
propylene oxide
propylene oxide
Constituent 2
Reference substance name:
EC Number:
EC Name:
Cas Number:
Details on test material:
Test material was racemate from both R(+) and S(-) propylene oxide. This endpoint is not measured / determined with enantio-selective sensors.
Therefore the S(-) value is identical to the racemate endpoint.

Results and discussion

Water solubility
Water solubility:
400 g/L
20 °C
Details on results:
The water solubility of propylene oxide is quoted as 395 g.l-1 at 20°C (Jefferson Chemicals,
1960). No method or data were provided and sample purity was not given. A value of 370 g.l-1
at 25°C (Amoore and Hautala, 1983) was quoted from the literature, but no reference was given
and no further details were provided. In both cases the pH of the solutions was not reported. A
solubility of ~400 g.l-1 at 20°C and pH 7 was reported (BASF, 1995). This was described as
“valid with restrictions”, however no further details were provided. A value of 405 g.l-1 is
widely quoted in secondary literature, and apparently comes from the American Chemical
Society Monograph Series: Glycols (1952). Co-incidentally, a value of 40.5% v/v (IARC, 1985)
is quoted, equivalent to 336 g.l-1. This seems rather low and could be a transcription error.

Any other information on results incl. tables

Propylene oxide and water are mutually soluble. Above 84.1°C propylene oxide and water are miscible in all proportions (Jefferson Chemicals, 1960); below this temperature a two-phase system exists.

Applicant's summary and conclusion

Interpretation of results (migrated information): very soluble (> 10000 mg/L)
Insufficient detail of the methods and analytical techniques makes it difficult to assess the accuracy of the data. A value of 400 g/l at 20°C shall be used as representative for the exposure assessment