Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Considering its high water solubility, NaOH is not expected to bioconcentrate in organisms. High water solubility and low vapor pressure indicate that NaOH will be found predominately in the aquatic environment.
The 73% aqueous solution of NaOH at ambient temperatures is a highly viscous, gelatinous material and without additional dilution (precipitation), it is not expected to infiltrate soil to any significant extent. The 50% aqueous solution of NaOH is liquid and is expected to infiltrate soil to a measurable degree. As the dilution of NaOH
increases, its speed of movement through soil increases. During movement through soil, some ion exchange will occur.
Also, some of the hydroxide may remain in the aqueous phase and will move downward through soil in the direction of
groundwater flow (OECD SIDS of sodium hydroxide of 2002, section 3.3.2, page 45).