Phosphoric acid, hexadecyl phosphate esters, potassium salts with cetostearyl alcohol

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

From July 20, 2017 to September 21, 2017

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

suspected to be influenced by trapped gases/impurities; issues with pressure equilibration

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

EU Regulation (EC) 440/2008, Annex Part A test A4.

Deviations:

not specified

GLP compliance:

yes

Type of method:

static method

Key result

Test no.:

#1

Temp.:

ca. 20 °C

Vapour pressure:

ca. 34 Pa

Remarks on result:

other: Calculated extrapolated value

Full test results

Temp/°C	Temp/K		P/mbar	**P/Pa
		Run 1
20.1	293.25		10.6	1060
		Run 2
*20	293.15		0.34	34
20.5	293.65		0.4001	40.01
30.1	303.25		0.9921	99.21
40.8	313.95		3	300
45.0	318.15		4.8	480
50.0	323.15		7.6	760
55.0	328.15		16.1	1610

* - Determined by extrapolation

** - Calculated

Comment

For test run 1, test substance was degassed over a period of 3 h at -10°C.

During testing, there was temperature equilibration but pressure equilibration was not achieved after 24 h. The testing was therefore test was terminated.

 

For test run 2, the test substance was ground and placed under vacuum for 15 h.

Conclusions:

Under the study conditions, the vapour pressure of the test substance was determined to be 34 Pa at 20°C.

Executive summary:

A study was conducted to determine the vapour pressure of the test substance using the static method, according to EC Method A.4, in compliance with GLP. For test run 1, test substance was degassed over a period of 3 h at -10°C. During testing, there was temperature equilibration but pressure equilibration was not achieved after 24 h. The testing was therefore test was terminated. For test run 2, the test substance was ground and placed under vacuum for 15 h. Under the study conditions, the vapour pressure of the test substance was extrapolated to be 34 Pa at 20°C (Chilworth, 2017).

Description of key information

The vapour pressure of the test substance was determined experimentally using static method, according to the EU A.4 Method (Chilworth, 2017) as well using QSAR models EPI Suite and T.E.S.T (US EPA, 2018).

Key value for chemical safety assessment

Vapour pressure:

0.001 Pa

at the temperature of:

25 °C

Additional information

- Experimental VP: 34 Pa (using static method); the VP value is suspected to be influenced by trapped gases/impurities.

- Weighted average QSAR based VP = 0.000568 Pa at 25°C (using EPI Suite v.4.11); 0.00125 Pa at 25°C (using T.E.S.T. v4.2.1). The estimates for the major constituents are considered to be reliable with restrictions, as they do not completely fall within of the applicability domain.

- VP values for the main constituents, phosphate esters (PSE) and alcohol: 0.00289 Pa at 20°C (using effusion method) for mono- and di- C16 PSE, K+ (ECHA REACH dossier on CAS 19035-79-1); 0.0013 Pa at 25°C (calculated from composition) for alcohols, C16-18 (OECD SIDS, 2006) respectively.

 

Overall, based on the above information the test substance can be considered to have low volatility potential. In absence of a reliable experimental value and the fact that the constituent alcohol, make up more than 80% of the composition, the VP value of the alcohol, which is 0.0013 Pa at 25°C, has been considered further for hazard/risk assessment as a conservative approach.