Choline hydroxide

Density

Link to relevant study record(s)

Reference

Endpoint:

relative density

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-03-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented guideline study (OECD 109) without restrictions.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 109 (Density of Liquids and Solids)

Deviations:

no

GLP compliance:

no

Type of method:

pycnometer method

Type:

relative density

Density:

1.08

Temp.:

20 °C

Remarks on result:

other: The relative density was determined to be 1.08 ± 0.01

Determination of the relative density

Measurements

Density of water at 20°C = 0.99821 g/mL (X); Density of water at 4°C = 1g/mL (Y)

	Test 1	Test 2
Weight of pycnometer (A) g	20.4521	22.9409
Weight of pycnometer + water (B) g	44.9200	47.8684
Weight of pycnometer (A1) g	20.4518	22.9407
Weight of pycnometer + test substance (C) g	46.9254	49.8688

Calculations Used to Determine Relative Density

 

Volume of pycnometer (mL)           V = (B - A) / X

 

Density of test substance (g/mL)    D1 = (C - A1) / V

Relative density                 D (20/4) = D1 / Y

Results

Using the values and equations above, the relative density for Tests 1 and 2 were calculated. 

	Test1	Test2
Volume of pycnometer (mL) (V)	24.5118	24.9722
Density of test substance (D1)	1.0800	1.0783
Relative Density   (D1/Y)	1.0800	1.0783

Mean relative density reported as 1.08 ± 0.01 at 20°C ± 0.5°C.

Conclusions:

The density of a 45% solution of choline hydroxide was determined in an OECD 109 guideline study, classified as reliable without restrictions. Hence, the results in general are considered as reliable and can be used for further risk assessment. Although the salt choline hydroxide is a solid compound, it is very hygroscopic and cannot be kept water-free under normal environmental conditions. Furthermore, it is marketed as an 45 % aqueous solution and is therefore the predominantly available form. Hence, it is justified out of scientific reasons and exposure considerations to regard choline hydroxide as aqueous solution. The outcome of this study is considered reasonable and within the scientifically expected ranges, the results are considered as valid because of their reproducibility.

Executive summary:

The relative density D(20/4) of a 45 % aqueous solution of choline hydroxide was determined according to OECD Guideline 109 (Density of Liquids and Solids / pycnometer method) to be 1.08 ± 0.001 at 20 °C ± 0.9 °C. D(20/4) describes the density of the substance at 20 °C in proportion to the density of water at 4 °C. The determination of the density of the aqueous solution of choline hydroxide is justified out of scientific reasons and exposure considerations and the results are within the scientifically expected range. The study was classified as Klimisch 1 and meets fully the OECD 109 guideline requirements.

Description of key information

Density of the aqueous solution of Choline hydroxide: 1.08 ± 0.01 at 20 ± 0.5 °C (OECD Guideline 109 (Density of Liquids and Solids))

Key value for chemical safety assessment

Relative density at 20C:

1.08

Additional information

The density of a 45 % solution of choline hydroxide was determined in an OECD 109 guideline study, classified as reliable without restrictions (Klimisch 1) and which meets fully the OECD 109 guideline requirements. Hence, the results in general are considered as reliable. The relative density D(20/4) describes the density of the substance at 20 °C in proportion to the density of water at 4 °C.

Although the salt choline hydroxide is a solid compound, it is very hygroscopic and cannot be kept water-free under normal environmental conditions. Furthermore, it is marketed as an 45 % aqueous solution and is therefore the predominantly available form. Hence, it is justified out of scientific reasons and exposure considerations to regard choline hydroxide as aqueous solution. The outcome of this study is considered reasonable, within the scientifically expected ranges, the results are considered as valid because of their reproducibility and can be used for further risk assessment.

Due to the reliability of the results and the choice of the test item with regard to the predominantly existing form of choline hydroxide, i.e. a 45 % aqueous solution, the tonnage-driven requirements under REACH are fully met, no datagaps were identified and no further testing is required.