RC - What is RC? - Rotterdam Convention

precolumn from which the compounds are directly injected into the
analytical column by rapid heating of the precolumn. The method was
reported to be suitable for the analysis of aqueous samples by
purging the precolumn following injection of the sample
(0.01-0.2 cm 3 ). The analytical method developed for volatile
halogenated compounds by Krost et al. (1982) was applied by
Pellizari (1982) and Barkley et al. (1980). Barkley et al.
(1980) also described the analysis of volatile halogenated
compounds
in water, blood and urine using a modification of this method: the
substances are recovered from water by heating and from biological
matrices by heating and purging and are subsequently trapped on a
Tenax column.
A spectrophotometric method for the determination of
hexachlorobutadiene in blood and urine has been reported. The
method
involves extraction by heptane and determination by either UV
spectroscopy or colorimetry after derivatization with pyridine.
Reported detection limits were 0.05 mg/litre for the UV method and
5 mg/litre for the colorimetric method (Gauntley et al., 1975).
Interference by other chlorinated hydrocarbons can be expected.
3. SOURCES OF HUMAN AND ENVIRONMENTAL EXPOSURE
3.1 Natural occurrence
Hexachlorobutadiene has not been reported to occur as a
natural
product.
&
and
3.2 Anthropogenic sources
3.2.1 Production levels and processes
The available data are in general of poor quality and not
up-to-date. Commercial production of hexachlorobutadiene was
reported to occur in Germany and Austria (SRI, 1984). In the USA,
commercial production was apparently terminated around 1970 (Mumma
Lawless, 1975). The compound was and is chiefly produced as
by-product of the manufacture of chlorinated hydrocarbons, often in
association with hexachlorobenzene. In the USA, the manufacture of
tetrachloroethene, trichloroethene and carbon tetrachloride
accounted in 1972 for over 99% of this production of
hexachlorobutadiene in heavy fractions, the so-called Hex-waste,
amounted to 3310-6580 tonnes (Brown et al., 1975; Mumma & Lawless,
1975; Yurawecz et al., 1976; see also section 3.2.3). It was also
reported to be a by-product of the manufacture of vinyl chloride,
allyl chloride and epichlorohydrin by chlorinolysis processes (Kusz
et al., 1984). Hexachlorobutadiene has been identified in the
effluents of sewage treatment plants (section 5.2) and as a
by-product of the pyrolysis of trichloro-ethene (Yasuhara & Morita,
1990) and plastics (Singh et al., 1982). The annual world
production of hexachlorobutadiene in heavy fractions was estimated
in 1982 to be 10 000 tonnes (Hutzinger, 1982). No data have been