Sodium O-isobutyl dithiocarbonate

PBT assessment

PBT assessment: overall result

Reference

Name:

Carbonodithioic acid, O-(2-methylpropyl) ester sodium salt

Type of composition:

legal entity composition of the substance

State / form:

solid: bulk

Reference substance:

Carbonodithioic acid, O-(2-methylpropyl) ester sodium salt

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence:

Sodium ethyl xanthate (CAS# 140-90-9) is readily biodegradable

Simulating test water, sediment (Analytical Department of Institute of Heavy Organic Synthesis "BLACHOWNIA", 2012, Kędzierzyn-Koźle, Poland; GLP certificate no. 4/2010/DPL).KS;Reliability 1; robust study summary available; Data owner – MINOVA-KSANTE Sp. z o.o.

Method: Dissolved Organic Carbon (DOC) Die-Away,(Regulation EC No 440/2008, method C.4-A)

A measured volume of inoculated mineral medium containing a known cocentration of the test substance (10-40 mg/l) as a source of organic carbon is aerated in the dark or diffused light at 22 +/- 2⁰C. Degradation is followed by DOC analysis at frequent intervals over 28-day period.

After 28 days biodegradation of sodium ethyl xanthate: D_28days= 100+/_1.4%

The above results indicate that sodium ethyl xanthate (CAS# 140-90-9) is ready biodegradable - pass level, according to OECD 301:

-          pass value in the 10 day window (form 1 day to 11 day)is 89% removal of DOC,

 

Bioaccumulation:

 Partition coefficient n-octanol/water.

Experimental result.Shake flask method according to A.8, EC No.440/2008 and OECD 107(Institute of Industrial Organic Chemistry, Active Ingredients Synthesis and Technology Department, GLP Compliance No 8/2011/DPL).

Calculated values of sodium ethyl xanthate (CAS# 140-90-9)partition coefficient 1-octanol/water

 

Vial number	1	2	3	4	5	6
Volume 1-octanol phase/volume of water phase	1:1		1:2		2:1
Pow= C1-octanol/Cwater	0.003167	0.003010	0.003599	0.003489	0.003265	0.003331
log Pow= log(C1-octanol/Cwater)	-2.50	-2.52	-2.44	-2.46	-2.49	-2.48
Average log Pow+ standard deviation	-2.51±0.01		-2.45±0.01		-2.49±0.01
Average log Pow+ standard deviation	-2.48±0.03

 

Partition coefficient n-octanol/water of sodium ethyl xanthate (CAS# 190-90-9) is very low.

BCFWIN - Arnold-Gobas BCF&BAF methods (including biotransformation rate estimates for fish)(US EPA. 2011. Estimation Program Interface Suite for Microsoft Windows v 4.10 United States Environment Protection Agency ,Washington ,DC, USA, http://epa.gov/oppt/exposure/pubs/episuite.htm)

 (file://C:\(x86)Common Files\QSAR Toolbox\Ver2.2\config)

BAF =1.397dm³/kg wet-wtupper trophic

 

PBT Profiler Estimate (http://www.pbtprofiler.net/ChemDetails?I=0)

The estimated bio-concentration factors:

sodium ethyl xanthate:                             BCF = 3.2

Very low values of: Experimental result of log P_ow, estimated values of BAF (Bio-accumulation Factor) and BCF (Bio-concentration Factor) indicate that bio-accumulation of sodium ethyl xanthate (CAS# 140-90-9) is unlikely.

Toxicity:

Predicted no effect concentration – PNEC = 0,001mg/dm³in water.

Canadian Centre for Occupational Health and Safety, 2010 ; Registry for Toxic Effects of Chemical Substances

According to REACH criteria Sodium ethyl xantate (CAS# 140-90-9) should be consider as very toxic for aquatic environment .