Pyridine-2-thiol 1-oxide, sodium salt

Biodegradation in water: screening tests

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Sodium pyrithione, which is completely ionized in water, was shown to be readily biodegradable under the conditions of OECD 301B (see Table 5.2.1) in two separate studies. 

The major non transient metabolite, pyridine sulphonic acid, was also shown to be readily biodegradable under the conditions of OECD 301B (5.2.1.003, EZPTF 7011-213).   

Table 5.2.1 Ready Biodegradability of NaPT, and the primary non-transient degradation product 2-Pyridine sulphonic acid (PSA)

Guideline / Test method	Test type^1	Test parameter	Inoculum			Additional substr.	Test substance concentr.	Degradation		Reference
			Type	Concen­tration	Adap­tation			Incubation period	Degree [%]
OECD guideline 301B	ready	CO2evolution	Activated sludge	30 mg dry material per litre	No	No	NaPT 30.2 mg/L (5 mg carbon/L)	28 d	0 % degradation after 6 days, 24 % degradation after 20 days 79 % degradation after 28 days	5.2.1.002 EZPTF 7011-214 Clarke (2002)
92/69/EEC, C.4-C. OECD 301B.	ready	CO2evolution	Activated sludge	30 mg dry material per litre	No	No	NaPT 10 mg/L	43 d	2 % degradation after 8 days, 60 % degradation after 18 days, 70% degradation after 43 days.	5.2.1.001 ESPTF 7011-211 Jenkins (1998)
OECD guideline 301B	ready	CO2evolution	Activated sludge	30 mg dry material per litre	No	No	PSA 26.5 mg/L (10 mg carbon/L)	29 d	49 % degradation after 6 days, 64 % degradation after 14 days 73 % degradation after 28 days	5.2.1.003 EZPTF 7011-213 Clarke (2002)

The information contained within this robust summary document comes from studies which are in the ownership of Arch Chemicals Inc. and which are protected in several regions globally. This information may not be used for any purpose other than in support of the Chemical safety Report submitted by Arch Chemicals Inc. under RegulationEC 1907/2006.