Chemical Properties
White, off-white or pale yellow crystalline solid.
Slight, sweet odor; ester-like.
Chemical Properties
Light yellow solid
Uses
Metsulfuron-methyl is an organic micro-pollutant.
Uses
Metsulfuron-methyl is a triazine urea herbicide used to control broad-leaved weeds
in barley and wheat.
Definition
ChEBI: A N-sulfonylurea in which the sulfonyl group is attached to a 2-(methoxycarbonyl)phenyl group while a (4-methoxy-6-methyl-1,3,5-triazin-2-yl group replaces one of the amino hydrogens of the remaining urea group.
Agricultural Uses
Herbicide: Metsulfuron-methyl is a pre-emergence and
post-emergence herbicide used to control annual grasses,
brush, woody plants and broadleaf weeds. It can be applied
to cereals including barley, rye and wheat and to pastures.
It is primarily used to control brush, woody plants
and broadleaf weeds on rights-of-way, fence rows, storage
areas, highways and other non-crop areas.
Trade name
ALLIE®; ALLY®; ALLY-20DF®; ANSWER®;
BRUSH-OFF®; CANVAS®; CIMARRON®; DMC® WEED
CONTROL; DPD 63760H®; DPX 6376®; DPX-T 6376®;
ESCORT®; FINESSE®; GROPPER®; NUP®; PARTISAN
®; PASTURE® MD; RIVERDALE®; ROSULFURON®
Potential Exposure
Metsulfuron-methyl is a preemergence
and postemergence sulfonylurea herbicide used to control
annual grasses, brush, woody plants and broadleaf weeds. It
can be applied to cereals including barley, rye and wheat
and to pastures. It is primarily used to control brush, woody
plants and broadleaf weeds on rights-of-way, fence rows,
storage areas, highways and other noncrop areas.
Environmental Fate
Soil/
Plant. Hydrolyzes in soil and plants to nontoxic products (Hartley and Kidd,
1987). The half-life in soil varies from 7 days to 1 month (Hartley and Kidd, 1987).
Ismail and Lee (1995) studied the persistence of metsulfuron-methyl in a sandy loam
(pH 5.1) and clay soil (3.1) under laboratory conditions. Degradation was more rapid in
non-sterilized than in sterilized soil. In non-sterilized soil, the rate of degradation increased
with increasing soil moisture content. When the moisture level in the sandy loam and clay
soil was increased from 20 to 80% of field capacity at 35°C, the half-lives were reduced
from 9.0 to 5.7 and 11.2 to 4.6, days, respectively. The investigators concluded that the
disappearance of metsulfuron-methyl in soil resulted from microbial degradation and
chemical hydrolysis.
Metabolic pathway
In soils, under aerobic conditions, metsulfuron methyl
is degraded by the cleavage of the sulfonylurea
linkage, resulting in the formation of methyl 2-
(aminosulfonyl)benzoate, 4-methoxy-6-methyl-2-amino-
1,3,5-triazine, and saccharin as major products. Under
anaerobic conditons, free acid of metsulfuron methyl
and the resulting O-demethylation product are
identified. The formation of two ring-opening products at the triazine moiety is observed. Under acidic
conditions, hydrolytic degradation products identified
are involved in the soil degradation products. In plants,
the specific metabolites are identified as the
hydroxylation product of the phenyl ring of metsulfuron
methyl and 4-methoxy-6-hydroxymethyl-2-amino-1,3,5-
triazine. Mammalian metabolites are also included in
the soil metabolites.
Shipping
UN3077 Environmentally hazardous substances,
solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous
material, Technical Name Required.
Incompatibilities
Strong oxidizers. Stable in air to about
140 C. It is hydrolyzed in acid solutions.
Waste Disposal
It is the responsibility of
chemical waste generators to determine the toxicity and
physical properties and of a discarded chemical and to
properly identify its classification and certification as a hazardous
waste and to determine the disposal method. United
States Environmental Protection Agency guidelines for the
classification determination are listed in 40 CFR Parts
261.3. In addition, waste generators must consult and follow
all regional, national, state and local hazardous waste
laws to ensure complete and accurate classification and disposal
methods. Recycle any unused portion of the material
for its approved use or return it to the manufacturer or
supplier. Offer surplus and nonrecyclable solutions to a
licensed disposal company. Dissolve or mix the pesticide
with a combustible solvent and burn in a chemical incinerator
equipped with an afterburner and scrubber.
