Choline hydroxide

Endpoint summary

Description of key information

No study on skin and eye irritation available; however, the pH value of pH = 14.9 (45 % aqueous solution, Struyvelt E, 2012) and various dilutions of this solution have a pH value of pH = 13.1 – 14.2 (10 - 90 % (w/w) of 45 % solution in water, Intertek, 2013))

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is a strong acid (pH ≤ 2.0) or base (pH ≥ 11.5) and the available information indicates that it should be classified as skin corrosion (Category 1, 1A, 1B or 1C)

Endpoint conclusion

Endpoint conclusion:

no study available

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is classified as skin corrosion, leading to classification as serious eye damage (Category 1)

the study does not need to be conducted because the substance is a strong acid (pH <= 2.0) or base (pH => 11.5) and the available information indicates that it should be classified as serious eye damage (Category 1)

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

According to REACH Annex VII Column 1 the assessment of the endpoint “skin irritation” shall comprise the following consecutive steps:

(1) an assessment of the available human and animal data,

(2) an assessment of the acid or alkaline reserve,

(3) in vitro study for skin corrosion,

(4) in vitro study for skin irritation

 

According to column 2, steps 3 and 4 do not need to be conducted if i.a. the available information indicates that the criteria are met for classification as corrosive to the skin or irritating to eyes. These criteria are met because the product (45 % Choline Base solution) has a pH = 14.9 (Struyvelt E, 2012) and various dilutions of this solution have a pH value of pH = 13.1 – 14.2 (10 - 90 % (w/w) of 45 % solution in water, Intertek, 2013) and hence, the test for skin irritation / corrosion of choline hydroxide does not need to be conducted.

 

Also, according to REACH Annex VII Column 1 the assessment of the endpoint “eye irritation” shall comprise the following consecutive steps:

(1) an assessment of the available human and animal data,

(2) an assessment of the acid or alkaline reserve,

(3) in vitro study for eye irritation.

According to column 2, step 3 does not need to be conducted if i.a. the available information indicates that the criteria are met for classification as corrosive to the skin or irritating to eyes. These criteria are met, as stated above, and hence, the test does not need to be conducted.

 

So, in summary, choline hydroxide needs to be classified as skin and eye corrosive, the tonnage-driven data requirements under REACH are fully met, no datagaps were identified and no further testing needs to be performed.

Justification for selection of skin irritation / corrosion endpoint:
According to REACH Annex VII Column 1 the assessment of this endpoint shall comprise the following consecutive steps:
(1) an assessment of the available human and animal data,
(2) an assessment of the acid or alkaline reserve,
(3) in vitro study for skin corrosion,
(4) in vitro study for skin irritation
According to column 2, steps 3 and 4 do not need to be conducted if i.a. the available information indicates that the criteria are met for classification as corrosive to the skin or irritating to eyes. These criteria are met because the product (45 % Choline Base solution) has a pH = 14.9 (Struyvelt E, 2012) and various dilutions of this solution have a pH value of pH = 13.1 – 14.2 (10 - 90 % (w/w) of 45 % solution in water, Intertek, 2013) and hence, the test does not need to be conducted.

Justification for selection of eye irritation endpoint:
According to REACH Annex VII Column 1 the assessment of this endpoint shall comprise the following consecutive steps:
(1) an assessment of the available human and animal data,
(2) an assessment of the acid or alkaline reserve,
(3) in vitro study for eye irritation.
According to column 2, step 3 does not need to be conducted if i.a. the available information indicates that the criteria are met for classification as corrosive to the skin or irritating to eyes. These criteria are met because the product (45 % Choline Base solution) has a pH = 14.9 (Struyvelt E, 2012) and various dilutions of this solution have a pH value of pH = 13.1 – 14.2 (10 - 90 % (w/w) of 45 % solution in water, Intertek, 2013) and hence, the test does not need to be conducted.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

Due to the high pH-value of the test item (pH = 14.9 (45 % solution, Struyvelt E, 2012), pH = 13.1 – 14.2 (10 - 90 % (w/w) of 45 % solution in water, Intertek, 2013) and pKb value (pKb = 5.06 for 0.0064-0.0403 M solutions (Seidel A (ed.) 2004. Kirk-Othmer Encyclopedia of Chemical Technology, Fifth edition, Wiley-Interscience, John Wiley & Sons, Inc., Publication)), choline hydroxide needs to be classified as corrosive to the skin and eye, according to Regulation 1272/2008/EC.