Choline hydroxide

Viscosity

Link to relevant study record(s)

Reference

Endpoint:

viscosity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-03-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented guideline study (OECD 114) 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 Test Guideline 114 (Viscosity of Liquids)

Deviations:

no

GLP compliance:

no

Type of method:

other: rotational rheometer

Temp.:

20°C

Parameter:

dynamic viscosity (in mPa s)

Value:

25.3

Remarks on result:

other: At 20 °C, the behaviour of the test substance was found to be Newtonian over the measured shear range of 10 to 200 1/s.

Temp.:

40°C

Parameter:

dynamic viscosity (in mPa s)

Value:

10.6

Remarks on result:

other: At 40 °C, the behaviour of the test substance was found to be Newtonian over the measured shear range of 10 to 200 1/s.

Raw data of the individual tests

 

Table 1. Test 1 at 20 °C, Individual Test Result = 25.20 mPa.s

1329003 10468749 T1 @ 20 °C
Time s	Temperature °C	Shear Stress Pa	Shear Rate 1/s	Viscosity Pas	Target Shear Rate 1/s
50.0	20.0	0.2498	9.955	0.02510	10.00
100.1	20.0	0.3189	12.16	0.02623	12.21
150.1	20.0	0.3726	14.84	0.02511	14.91
200.2	20.0	0.4550	18.12	0.02511	18.21
250.3	20.0	0.5562	22.13	0.02513	22.23
300.4	20.0	0.6794	27.02	0.02514	27.14
350.5	20.0	0.8303	33.00	0.02516	33.14
400.6	20.0	1.007	40.29	0.02499	40.47
450.6	20.0	1.239	49.20	0.02518	49.42
500.7	20.0	1.517	60.07	0.02525	60.34
550.8	20.0	1.847	73.35	0.02518	73.68
600.9	20.0	2.256	89.57	0.02519	89.97
651.0	20.0	2.757	109.4	0.02521	109.9
701.1	20.0	3.365	133.5	0.02520	134.1
751.2	20.0	4.105	163.1	0.02518	163.8
801.3	20.0	5.024	199.1	0.02523	200.0

 

 

Table 2. Test 2 at 20 °C, Individual Test Result = 25.43 mPa.s

1329003 10468749 T2 @ 20 °C
Time s	Temperature °C	Shear Stress Pa	Shear Rate 1/s	Viscosity Pas	Target Shear Rate 1/s
50.02	20.0	0.2518	9.955	0.02529	10.00
100.1	20.0	0.319	12.16	0.02624	12.21
150.2	20.1	0.3757	14.84	0.02531	14.91
200.3	20.0	0.4585	18.12	0.02530	18.21
250.4	20.0	0.5596	22.13	0.02528	22.23
300.5	20.0	0.6838	27.02	0.02531	27.14
350.6	20.0	0.8353	33.00	0.02531	33.14
400.6	20.0	1.024	40.29	0.02542	40.47
450.7	20.0	1.247	49.20	0.02535	49.42
500.8	20.0	1.528	60.07	0.02544	60.34
550.9	20.0	1.864	73.35	0.02541	73.68
601	20.0	2.276	89.57	0.02541	89.97
651.1	20.0	2.78	109.4	0.02542	109.9
701.2	20.0	3.399	133.5	0.02545	134.1
751.3	20.0	4.153	163.1	0.02547	163.8
801.4	20.0	5.071	199.1	0.02547	200.0

 

 

Table 3. Test 1 at 40 °C, Individual Test Result = 10.57 mPa.s

1329003 10468749 T1 @ 40 °C
Time s	Temperature °C	Shear Stress Pa	Shear Rate 1/s	Viscosity Pas	Target Shear Rate 1/s
50.0	40.0	0.1047	9.955	0.01052	10.00
100.1	40.0	0.1129	12.16	0.009289	12.21
150.1	40.0	0.156	14.84	0.01051	14.91
200.2	40.0	0.1899	18.12	0.01047	18.21
250.3	40.0	0.2316	22.13	0.01047	22.23
300.4	40.0	0.2843	27.02	0.01052	27.14
350.5	40.0	0.3467	33.00	0.01051	33.14
400.6	40.0	0.4352	40.29	0.01080	40.47
450.7	40.0	0.5181	49.20	0.01053	49.42
500.8	40.0	0.6374	60.07	0.01061	60.34
550.9	40.0	0.7769	73.35	0.01059	73.68
601.0	40.0	0.9473	89.57	0.01058	89.97
651.1	40.0	1.158	109.4	0.01059	109.9
701.2	40.0	1.413	133.5	0.01058	134.1
751.3	40.0	1.722	163.1	0.01056	163.8
801.4	40.0	2.111	199.1	0.01060	200.0

 

 

Table 4. Test 2 at 40 °C, Individual Test Result = 10.56 mPa.s

1329003 10468749 T2 @ 40 °C
Time s	Temperature °C	Shear Stress Pa	Shear Rate 1/s	Viscosity Pas	Target Shear Rate 1/s
50.02	40.0	0.1035	9.955	0.01039	10.00
100.1	40.0	0.1399	12.16	0.01151	12.21
150.1	40.0	0.1549	14.84	0.01043	14.91
200.2	40.0	0.1898	18.12	0.01047	18.21
250.3	40.0	0.2321	22.13	0.01049	22.23
300.4	40.0	0.2828	27.02	0.01047	27.14
350.5	40.0	0.3451	33.00	0.01046	33.14
400.6	40.0	0.4308	40.29	0.01069	40.47
450.7	40.0	0.5161	49.20	0.01049	49.42
500.8	40.0	0.6367	60.07	0.0106	60.34
550.9	40.0	0.7745	73.35	0.01056	73.68
601	40.0	0.9434	89.57	0.01053	89.97
651	40.0	1.152	109.4	0.01054	109.9
701.1	40.0	1.408	133.5	0.01054	134.1
751.2	40.0	1.723	163.1	0.01057	163.8
801.3	40.0	2.103	199.1	0.01056	200.0

 

Conclusions:

The viscosity of a 45 % solution of choline hydroxide was determined in an OECD 114 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, which requires to perform the testing for viscosity instead of a particle size distribution. The outcome of this study is considered reasonable and within the scientifically expected ranges.

Executive summary:

The viscosity of a 45 % aqueous solution of Choline hydroxide was determined according to OECD Test Guideline 114 (Viscosity of Liquids / rotational viscometer) to be 25.3 mPa.s at 20 °C and 10.6 mPa.s at 40 °C. The determination of the viscosity 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 114 guideline requirements. 

Description of key information

In accordance with section 1 of REACH Annex XI the study does not need to be conducted as it is technically not feasible: the substance is a solid.

Viscosity of a 45 % aqueous solution of Choline Base: 25.3 mPa.s at 20 °C and 10.6 mPa.s at 40 °C (OECD Guideline 114 (Viscosity of Liquids / rotational viscometer))

Key value for chemical safety assessment

Viscosity:

25.3 mPa · s (dynamic)

at the temperature of:

20 °C

Additional information

In accordance with section 1 of REACH Annex XI the study does not need to be conducted as it is technically not feasible: the substance is a solid.

 

The viscosity of a 45 % solution of choline hydroxide was determined in an OECD 114 guideline study, classified as reliable without restrictions (Klimisch 1) and which meets fully the OECD 114 guideline requirements. Hence, the results in general are considered as reliable.

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 a 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, which requires the performance of the testing for viscosity instead of a particle size distribution. The outcome of this study is considered reasonable, within the scientifically expected ranges and can be used for further risk assessment.

Due to the reliability of the results and the choice of the test method 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.