S-allyl O-pentyl dithiocarbonate

Endpoint summary

Additional information

Probable Routes of Human Exposure:

NIOSH (NOES Survey 1981-1983) has statistically estimated that 45,760 workers (5,834 of these are female) are potentially exposed to carbon disulfide in the US(1). Occupational exposure to carbon disulfide may occur through inhalation and dermal contact with this compound at workplaces where carbon disulfide is produced or used(SRC). Monitoring data indicate that the general population may be exposed to carbon disulfide via inhalation of ambient air, ingestion of fruits and vegetables and other food products containing carbon disulfide(SRC).

Monotoring data

Monitoring for S-allyl O-pentyl dithiocarbonate is not carried out at either the sites of manufacture or end-use.

Monitoring is carried out for carbon dioxide which is expected to be released during manufacture, storage and use of S-allyl O-pentyl dithiocarbonate.

 

Air monitoring data, although limited and of poor quality, indicate that the atmospheric levels of carbon dioxide; oxides are below 10 ppm in the flotation areas. The risk to workers during the flotation process is considered to be low.

 Monitoring is however carried out for CS2,which is considered to be the major hazard during manufacture, storage and use of xanthates.

Xanthates and xanthate ester in the presence of heat/moisture decompose and under the conditions of storage and use the major decomposition product is carbon disulphide.

Routine air monitoring for CS2 is recommended at xanthate manufacturing plants and end-use facilities, particularly in areas where CS2 levels may exceed theexposure standard. In particular, static monitoring should be carried out prior to maintenance activities to as certain CS2 exposure levels, in order to determine the type of personal protective equipment deployed.

The NOHSC occupational exposure standard for CS2 is 10 ppm (31 mg/m3) (time weighted average), with a skin notation (NOHSC 1995). This standard has been adopted from the US ACGIH TLV documentation, which is apparently based on “cardiovascular effects in workers exposed to air concentrations of between 10- 40 ppm CS2 and systemic effects observed following skin absorption” (ACGIH 1998).

This standard is listed in Appendix 3 (substances under review) of the NOHSC Guidance Note (NOHSC 1995) as requiring review due to ‘neurological and cardiovascular effects’.

Table1provides details of known national exposure standards adopted for CS2.

 

Country	Exposure limits				Skin notation
	TWA		STEL
	ppm	mg/m3	ppm	mg/m3
US NIOSH	1	3	10^1(500)^2	30	yes
Hungary	2	5	3	10	yes
Czechoslovakia	3	10	6	20
Denmark	5	15	-	-	yes
Sweden	5	16	8	25	yes
Poland	6	18	10	30
Australia	10	31	-	-	yes
Finland	10	30	20	60	yes
France	10	30	25	75
Germany (DFG)	10^3	32	-	-
Japan (JSOH)4	10	31	-	-	yes
Netherlands5	10	30	-	-	yes
Russia	10	30	-	-
Switzerland	10	30	20	60	yes
United Kingdom	10	32	-	-	yes
(HSE)
US ACGIH	10	31	-	-	yes
US OSHA6	20	65	-	-

 

 

N.B. Source: ACGIH (1998) – Standards current as at Jan 1993 unless otherwise

indicated.

1 = 15-min ceiling concentration

2 = IDLH concentration

3 = Pregnancy Group B (probable risk of damage to developing embryo/foetus)

4 = 1996

5 = Oct 1997

6 = 1995

Currently, the highest TWA exposure limit for CS2 (PEL: 20 ppm) is that set by the US OSHA -TWA (OSHA 1995). This exposure limit reflects the exposure limit that was in effect prior to the issuance of revised limits of 4 ppm (PEL), 12ppm (STEL) and 500 ppm (IDLH) in January 1989, apparently established to“reduce substantially the significant risks of cardiovascular disease, neurologicalimpairment, and adverse reproductive effects associated with exposures to CS2”(OSHA 1989). These revised limits were voided by the US Eleventh CircuitCourt of Appeals on 7 July 1992 (ATSDR 1996).

Levels of carbon disulfide in surface waters

Data on levels of carbon disulfide in surface waters are limited to southern Ontario, Canada. Background levels at remote sites in Ontario, largely due to biogenic production, ranged between about 0.005 and 0.4 µg/litre (Caron & Kramer, 1994). In Lake Ontario, in 1981, a median concentration of 0.4 µg/litre and a maximum of 3.9 µg/litre were measured (Kaiser et al., 1983). The authors considered that the lower levels in the open lake were likely due to biogenic activity, while the elevated levels were due mainly to the influence of nearby urban/industrial areas (B. Scott, personal communication, 1998). The highest measured concentration in surface water, 25.0 µg/litre, was associated with a chemical plant on Thompson Creek in the Niagara region that has since closed (Kaiser & Comba, 1983).

Levels of carbon disulfide in seawater

In seawater, Lovelock (1974) reported concentrations in the open Atlantic of 0.52 and 0.78 ng/litre off the coast of Ireland and 5.4 ng/litre in stagnant bay water near Ireland. Leck & Rodhe (1991) measured levels of carbon disulfide between 0.83 and 1.18 ng/litre in the open Baltic and North seas. Kim & Andreae (1987) reported concentrations of carbon disulfide in surface waters in the North Atlantic ranging between 0.01 and 4.6 ng/litre. Data on levels in groundwater were not identified.

Levels of carbon disulfide in soil

Only limited data on concentrations of carbon disulfide in soils were identified. In a 1985-1986 study of background sites in the general vicinity of petrochemical refinery facilities west of Toronto, Ontario, carbon disulfide was detected at one of five sites in Port Credit at 0.000 11 µg/g, but not at any of six sites from Oakville/Burlington (Golder Associates, 1987). In a 1987 survey of organic compounds in surface soils in background areas in the same municipalities, carbon disulfide was detected at 3 of 30 urban residential and parkland sites in Port Credit, Oakville, and Burlington, at concentrations of 0.10, 0.10, and 0.14 µg/g, respectively (Golder Associates, 1987). However, reported levels were near the method detection limit (0.10 µg/g), and the values were not corrected for the observed contamination of the method blank.

In 1988, carbon disulfide was measured in sedi-ment suspensions taken from Lake Ontario, near Burlington, Ontario, and in Harp Lake, near Huntsville, Ontario. Caron & Kramer (1994), using a sulfur-specific gas chromatographic method, were able to detect 5.9 ng carbon disulfide/litre in Lake Ontario sediments and 9.7 ng carbon disulfide/litre in Harp Lake sediments.

Levels of carbon disulfide in air

Western Mining Corporation submitted data from a review undertaken by Industrial Risk Management Pty Ltd 36 of more than 400 atmospheric samples reported to the Department of Mines. The samples measured carbon disulphide levels at their various mining operations and the results showed that:

• the maximum carbon disulphide level measured was 15 ppm in the mixing

section;

• only two readings were above 10 ppm;

• only 20 readings were at or above 5 ppm and most of these were recorded as being

in the “mixing section”; and

• the average concentration of atmospheric carbon disulphide from 133 samples

taken in the mixing section was less than 2.5 ppm.