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

19 Isoproturon
� Isoproturon is an herbicide used in cereal production
across Europe to control grasses and
broadleaves.
� In Norway, isoproturon is prohibited to use
from 2006.
� The substance is very toxic for aquatic organisms
and moderately persistent.
� The levels found in Norwegian environment
are low, but data is very limited. There is further
need for screening.
Production and use
Isoproturon has been allowed to use in Norway
until 2006, but sales were stopped by the
importer in 2003. Isoproturon has been in agricultural
use since 1985, and about 66 000 kilos
has been sold in Norway. It has been used on
cereals, often against annual bluegrass (Poa
annua). The product was cancelled because it
may cause cancer, and because it may pollute
groundwater.
Emissions, discharges,
distribution and hot-spots
The main source in Norway is agricultural use.
Monitoring
Isoproturon has been monitored in JOVÅ. Time
trends exist.
Fresh water
Isoproturon has not been investigated in marine
environments in Norway, nor in ground water.
Eight rivers and streams have been analyzed and
isoproturon was found in the stream
Finsalbekken in Hamar in Hedmark County.
The levels in Finsalbekken were relatively high,
and may be due to specific soil pollution.
Hot spots
The concentrations of isoproturon in
Finsalbekken could be caused by a hot spot.
Need for further screening and monitoring
There are hardly any data, and isoproturon is
still being used. These are indications that further
studies of isoproturon should be considered.
isoproturon ::::::::::..
Localities for further screening and monitoring
Isoproturon should be included in future screening
of both marine and fresh water environment.
Finsalbekken and the area around it should also
be investigated in order to establish new knowledge
of the situation there.
Analysis
The analysis of isoproturon is often part of
multi pesticide packages offered by several laboratories.
Methods
The methods are based on direct extraction with
an organic solvent (sediment and biota) or solid
phase extraction (SPE), clean-up with SPE and
separation and quantification with LC-based
methods: LC/MS or LC/UV.
S
FACTS
Cas no.: 34123-59-6
Synonyms: 3-(4-isopropylfenyl)-1,1-dimetylurea,
Arelon (product name Norway) Alon; Belgran; DPX
6774; Graminon; IP50; Tolkan.
Properties: White to yellowish powder/solid crystalline.
Toxic effects: Isoproturon has only slightly acute toxicity,
LD50 (rat oral) > 2000 mg/kg. Isoproturon is a
skin irritant and possible carcinogen. Isoproturon is
highly toxic to aquatic organisms.
Log Kow: 2,84
Persistence: DT50 water = 20 - 61 days
DT50 whole system = 44 - 276 d (CIRCA)
BCF 2,6-3,6.
Water solubility: 143,8 mg/l
Molecular formula: C 12 H 18 N 2 O
Metabolites: Desmethylisoproturon
Use: Isoproturon is used as herbicide, often in cereal
production, against annual grasses and broadleaves.
It was re-evaluated in the EU in 2001, and it is certified
for use in Sweden.
A study of the priority substances of the Water Framework Directive
TA-2140/2005
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