Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

No experimental data on any of the environmental endpoints is available for sodium 2 -mercaptoethanolate. The 2-mercapthoethanolate ion is a conjugated base, 2-mercaptoethanol (CAS 60-24-2) its undissociated acid. With a pKa value of ca. 9.5 for both substances, in an aqueous environment with pH 7, they will be present almost exclusively as 2-mercaptoethanol. Therefore, fate parameters in aqueous environments are assessed by by read-across to 2 -mercaptoethanol. More specific considerations on read-across are given in the endpoint specific sections.

All available relevant environmental fate data is tabulated below.

Physchem property

Key value for assessment


Phototransformation in air

Half-life: ca 6 hours

AOPWIN (v1.92) estimation


Not expected / probable 

According to structural properties


Readily biodegradable

Brands, 2016

(read across to 2 -mercaptoethanol) 

Adsorption / desorption

Koc: ca. 2 (log Kow = 0.28) 

KOCWIN (v2.00) estimation (MCI method)

(read across to 2 -mercaptoethanol) 

Henry’s Law Constant

HLC: 0.0129 Pa·m3/mole 

HENRYWIN (v3.20) estimation (Bond method)

(read across to 2 -mercaptoethanol)