Peracetic acid

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

not specified

Type of method:

thermal analysis

Key result

Melting / freezing pt.:

-43.9 °C

Atm. press.:

101 325 Pa

Decomposition:

no

Sublimation:

no

Remarks on result:

other: Calculated value for 100% peracetic acid

Melting / freezing pt.:

>= 18.8 °C

Atm. press.:

ca. 101 325 Pa

Remarks on result:

other: PAA conc. 40%

Melting / freezing pt.:

>= 16.7 °C

Atm. press.:

ca. 101 325 Pa

Remarks on result:

other: PAA conc.35%

Melting / freezing pt.:

>= 14.7 °C

Atm. press.:

ca. 101 325 Pa

Remarks on result:

other: PAA conc. 30%

Melting / freezing pt.:

>= 12.6 °C

Atm. press.:

ca. 101 325 Pa

Remarks on result:

other: PAA conc. 25%

Melting / freezing pt.:

>= 10.5 °C

Atm. press.:

ca. 101 325 Pa

Remarks on result:

other: PAA conc. 20%

Plotting the results shows linear behaviour with R²=0.9999 and an equation of:

freezing temp = -0.4179 * percentage dPAA – 2.1107

From this equation the freezing point of 100% dPAA is calculated as -43.90 °C

Conclusions:

The freezing point of 100% dPAA is calculated as -43.90 °C

Executive summary:

From a series of determinations the freezing point of 100% dPAA is calculated as -43.90 °C.

Reference 2

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Peer reviewed data

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

not specified

GLP compliance:

no

Melting / freezing pt.:

-30 - -26 °C

Atm. press.:

other: normal pressure

Decomposition:

no

Sublimation:

no

Remarks on result:

other: 5% equilibrium solutions

Melting / freezing pt.:

-50 - -30 °C

Atm. press.:

other: normal pressure

Decomposition:

no

Sublimation:

no

Remarks on result:

other: 15% equilibrium solutions

Melting / freezing pt.:

-44 °C

Atm. press.:

other: normal pressure

Decomposition:

no

Sublimation:

no

Remarks on result:

other: 35% equilibrium solutions

The results depend on the formulation, having the same PAA concentration but different concentrations of HOAc and H202, so that the physico-chemical properties may be completely different.

Conclusions:

The normal pressure data for a 5% peracetic acid solution show a melting point in the range of - 26 to – 30°C. The boiling point is in the range of about 100°C. For a 15% peracetic acid solution the melting point is in the range of - 30 to - 50°C.

Executive summary:

The melting point of a peracetic acid solution of certain peracetic concentration depends also the acetic acid and hydrogen peroxide. A higher peracetic acid content generally lowers the freezing/ melting point.

Reference 3

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2006-2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes

Type of method:

thermal analysis

Melting / freezing pt.:

-73 °C

Atm. press.:

1 013 hPa

Decomposition:

no

Sublimation:

no

The DSC measurements were performed twice, using crucible lids with one hole of 50 µm to determine a possible boiling point more precisely. The small hole causes the generation of a defined atmosphere at constant pressure inside the crucible and allows measurements at near equilibrium conditions, thus preventing evaporation of the test material before reaching the boiling point. The measurements were stopped before the temperature had reached 250 °C. In the first run the crucible cracked open at 127 °C, due to overpressure, probably caused by a closed up hole. The second run was stopped at 145 °C, because the heat flow curve indicated decomposition (exothermic). The sample had lost approx. 98.5 % of its mass at the end of the 2nd measurement without visible residue. Interpretation of the differential scanning calorimeter curve: The DSC-curves show a glass transition, followed by 2 crystallization peaks at -86 °C and -77 °C. Upon further heating a threefold melting peak in the range of approx. -73 °C to -47 °C is registered. The melting temperature is commonly defined by the extrapolated onset temperature of -73 °C. At approximately 50 °C an exothermic heat flow indicates a beginning decomposition reaction. An endothermic peak at 114 °C with an extrapolated onset temperature of 105 °C indicates the boiling point. The curve of the first run shows this peak only partially (closed up hole). A preliminary thermogravimetric measurement was performed over a temperature range from room temperature to 370 °C. A single step is registered with a maximum at 105 °C and a total mass loss of 87.5 %. The thermogravimetric curve and the DSC curves cannot be compared directly, since the thermogravimetric measurement was carried out in an open crucible (perforated lid with several holes), where evaporation takes place long before the boiling point is reached. Copies of the differential scanning calorimeter curves and the preliminary thermogravimetric curve of the test item are attached.

Conclusions:

Melting point of a 15.37 % peracetic acid, 25.56 % hydrogen peroxide and 14.27 % acetic acid solution in water is -73 °C.

Executive summary:

The melting temperature of the test item was determined by differential scanning calorimetry according to EEC-Directive 92/69 EEC, Part A, Methods for the determination of physicochemical properties, A. 1 "Melting temperature", EEC Publication No. L383, December 1992.

Melting temperature: -73 °C

Description of key information

From a series of determinations the freezing point equivalent to EU method A.1, the freezing point for 100% peracetic acid is calculated as -43.90 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

-43.9 °C

Additional information

The estimated melting point using the EPI (estimation program interface) Suite, developed by EPA's Office of Pollution Toxics and Syracuse Research Corporation for the pure peracetic acid is - 42 °C. There are several measured values reported for solutions. The melting point of a peracetic acid solution depends also on the acetic acid and hydrogen peroxide content. Measured melting points of 5% equilibrium solutions are found in the range of -26 °C to -30 °C, while the measured melting points of 15% equilibrium solutions range from -30 °C to -50 °C.

The melting point of “Peracetic acid 15%” was determined to be -73 °C according to EU method A.1.

From a series of determinations the freezing point equivalent to EU method A.1, the freezing point for 100% peracetic acid is calculated as -43.90 °C. This value is used as key value for chemical safety assessment.