|Chemical Abstract Number (CAS #)||
||EPA Method 619|
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| Nonselective preemergence & postemergence herbicide which controls most annual &
perennial broadleaf & grassy weeds
A NON-SELECTIVE HERBICIDE USED FOR CONTROL OF MOST ANNUAL &
PERENNIAL BROAD-LEAVED, GRASS & BRUSH WEEDS ON NON-CROP AREAS AT
10-20 KG AI/HA & MAY BE APPLIED TO THE GROUND BEFORE LAYING ASPHALT.
PROMETONE HAS BEEN USED FOR CONTROL OF DEEPROOTED PERENNIAL
GRASSES SUCH AS BERMUDA.
|Apparent Color|| COLORLESS POWDER; White, crystalline
|Melting Point|| 91-92 DEG C
|Molecular Weight|| 225.3
|Density|| 1.088 G/CU CM @ 20 DEG C
|Environmental Impact|| Prometone may be released to the environment during its manufacture, transport,
storage, formulation and use as a nonselective herbicide for the control of perennial broadleaf and
grassy weeds on non-agricultural land. When prometone is applied to soil, it will adsorb
moderately to the soil. It is moderately persistent in soil; its estimated half-life in soil is between
1.5 and 6 months. It is not known whether it degrades by chemical or microbial processes. An
important mechanism by which prometone is lost from soil is by volatilization. Prometone rises to
the soil surface with evaporating water and as the concentration of the herbicide at the soil-air
interface increases, the amount of prometone volatilizing increases. If released into water,
prometone will partially adsorb to sediment and particulate matter in the water column.
Degradation should be slow. Bioconcentration in fish should not be significant. Volatilization
should not be an important fate process. In the atmosphere, prometone would be expected to
degrade by reaction with photochemically produced hydroxyl radical; its estimated half-life is 2.4
hr. Exposure to prometone will be primarily occupational by skin contact. It is most likely to
occur while applying the herbicide or touching treated soil or vegetation. Exposure by inhalation
may occur when entering recently treated fields.
|Environmental Fate|| TERRESTRIAL FATE: TRIAZINES ARE NOT READILY DEGRADED BY
SOIL MICROORGANISMS. THUS, THEIR RATE OF DECAY IS RELATIVELY SLOW, &
AS THESE MATERIALS ALSO DO NOT READILY LEACH FROM THE SOIL, THEY
MAY PERSIST FOR QUITE EXTENDED PERIODS OF TIME. TRIAZINES
TERRESTRIAL FATE: THE RESIDUAL ACTIVITY OF PROMETONE IN SOIL
DEPENDS MAINLY UPON SOIL TYPE, MOISTURE & APPLICATION RATE. UNDER
ARID CONDITIONS, IT CAN PERSIST FOR EXTENDED PERIODS.
TERRESTRIAL FATE: When prometone is applied to soil, it will adsorb moderately to the soil.
Prometone is moderately persistent in soil; its estimated half-life in soil is between 1.5 and 6
months . It is not know whether it degrades by a chemical or microbial process . In a
greenhouse experiment using a ryegrass bioassay it took between 4.5 and 20 weeks and >60 wks
for 50% and 80% of prometone activity to disappear when the herbicide was applied at 0.25
lb/acre . At an application rate of 1.0 lb/acre >60 weeks were required for half of its
phytotoxicity to disappear. No prometone degraded during the course of a 24-day volatilization
experiment performed in a special chamber using moist San Joaquin sandy loam at a temperature
of 25 deg C . An important mechanism by which prometone is lost from soil is by volatilization.
Prometone rises to the soil surface with evaporating water and as the concentration of the
herbicide at the soil-air interface increases, its adsorption to the soil decreases and the amount of
prometone volatilizing increases. In one experiment 7.6% of applied prometone was lost in 14
days as a result of this wicking effect and subsequent volatilization . Of the 50 kg of prometone
used in four Ontario, Canada agricultural watersheds in 1975, an estimated 44 g were lost to
water . This is thought to be entirely a result of storm runoff and snow melt from
nonagricultural land .
AQUATIC FATE: If released into water, prometone will partially adsorb to sediment and
particulate matter in the water column. Volatilization should not be a significant fate process. No
estimates on the rates of microbial and abiotic degradative process are available. From the
available soil data, degradation will be very slow.
ATMOSPHERIC FATE: In the atmosphere, prometone would be expected to degrade by
reaction with photochemically produced hydroxyl radical. Its estimated half-life is 2.4 hr .
TERRESTRIAL FATE: THE LONG SOIL PERSISTENCE OF THESE CMPD DOES
CREATE THE PROBLEM OF SOIL CARRY OVER, WHICH CAN DAMAGE
SUCCEEDING CASH CROPS. THEREFORE EXTREME CAUTION MUST BE TAKEN IN
THEIR APPLICATION ON CROPLAND TO AVOID SUCH INJURY TO FOLLOWING
|Drinking Water Impact|| SURFACE WATER: In a survey of 11 agricultural watersheds in Ontario, prometone
was found in 0.2% and 1.5% of samples in 1975-6 and 1976-7, respectively . The mean
concentration in positive samples was 0.02 ppb; the highest sample concentration found was 0.1
ppb . Prometone was detected, but not quantified, in selected streams feeding into Lakes
Ontario, Erie, Huron and Lake St. Clair .
GROUNDWATER: Between 1968 and 1978, only one well out of 237 in Ontario, Canada,
analyzed because of suspected contamination, was found to contain prometone . The
contamination was caused by diluted herbicide directly or indirectly entering the well and the level
of contamination was between 11 and 100 ppb .
EFFL: Prometone was reported in the secondary effluent of a municipal treatment plant in
Illinois that received industrial discharges . The concentration of prometone in the effluent was