A study of the priority substances of the Water Framework Directive ...

..:::::::::: chlorpyrifos
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9 Chlorpyrifos
� Chlorpyrifos is one of the most common
insecticides worldwide. Increased popularity following
DDT ban.
� The substance has been found on imported
fruit and vegetables, but data on use and distribution
in Norway are limited.
� There are no data on environmental distribution
in Norway.
� There is no further need for screening of
Chlorpyrifos in Norway.
Production and use
In Norway, Chlorpyrifos has been used as insecticide
for ants. No sales for agricultural purposes
found in documentation on use and sales of
pesticides. No entries in the Product Register
since 2000.
Chlorpyrifos has been restricted banned from
agricultural use in in Sweden from 2001, but
becomes legal from 2005 as pesticide also due
to EC regulations.
It has also been used in veterinary and human
medicine (lice).
Emissions, discharges,
distribution and hot-spots
Chlorpyrifos may be found around arable lands
and possibly in landfills.
Monitoring
Chlorpyrifos has been screened in Sweden and
only been found in very low concentrations in a
fresh water stream and in compost. There are
no data on environmental distribution in
Norway.
Need for further screening and monitoring
The use of chlorpyrifos in Norway has been
very limited, and chlorpyrifos has not been
found in the environment. There is no need for
further screening or monitoring of chlorpyrifos.
Analysis
The analysis of chlorpyrifos is often part of
multi pesticide packages offered by several laboratories.
A study of the priority substances of the Water Framework Directive
TA-2140/2005
FACTS
Cas no.: 2921-88-2
Synonyms: Klorpyrifos, Dursban, chlorpyriphos (F-ISO,
JMAF), 0,0-Diethyl-0-3,5,6-trichlor-2-pyridylthiophosphat.
Properties: Granules, wettable powder, dustable
powder, and emulsifiable concentrate.
Toxic effects: Chlorpyrifos is toxic to humans. LD50 in
rats is 95 to 270 mg/kg. Skin and eye irritant. Toxic to
highly toxic to birds. Highly toxic to fresh water fish,
aquatic invertebrates and estuarine and marine
organisms. The 96-hour LC50 in rainbow trout
(Oncorhynchus mykiss) is 0,009 mg/L. Toxic to some
plants.
Log Kow: 4,66
Persistence: Up to 1 year in soil, half-life up to 80
days in water, may persist longer in groundwater and
sediments. BCF value 2,67. (HSDB)
DT50 water = 3-6 days
DT50 whole system = 22 -51 days (CIRCA)
Water solubility: 0,357 mg/l (25°C)
Molecular formula: C 9 -H 11 -Cl 3 -N-O 3 -P-S
Metabolites: 3,5,6-trichloro-2-pyridinol (urine), (3,5,6trichloro-2-pyridyl)phosphate.
Use: Insecticide. One of the pesticides most often
found in amounts exceeding the maximum residue
level according to Mattilsynet (2003).
Methods
The methods are based on direct extraction with
an organic solvent (sediment and biota) or solid
phase extraction (SPE), eventually clean-up with
SPE and separation and quantification with GCbased
methods: GC/MS or GC/NPD.
Synergy with other analyses
Sample extraction and clean-up can be co-ordinated
with the analysis of other pesticides which
can be analysed by GC/MS especially other
organophosphorous insecticides as for example
chlorfenvinphos, malathion or methylparathion.
References
� Royal Haskoning: Fact sheets on production,
use and release of priority substances in the