The information in this profile may be out-of-date. It was last revised
in 1996. EXTOXNET no longer updates this information, but it may be useful
as a reference or resource.
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updated pesticide fact sheets.
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E X T O X N E T
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and the Institute for Environmental Toxicology, Michigan State
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USDA/Extension Service/National Agricultural Pesticide Impact
EXTOXNET primary files maintained and archived at Oregon State
Revised June 1996
Trade and Other Names:
Trade names for products containing imazalil include Bromazil,
Deccozil, Fungaflor, Freshgard, and Fungazil. The fungicide is
compatible with many other types of pesticides.
Imazalil is a moderately toxic compound in EPA toxicity class II.
Labels for products containing it must bear the Signal Word
WARNING . Imazalil is a General Use Pesticide (GUP).
Imazalil is a systemic imidazole fungicide used to control a wide
range of fungi on fruit, vegetables, and ornamentals, including
powdery mildew on cucumber and black spot on roses. Imazalil is
also used as a seed dressing and for postharvest treatment of
citrus, banana, and other fruit to control storage decay. Under
natural conditions, it is less likely that imazalil treatment
will lead to resistant strains of fungi than as a result of
treatment with other fungicides.
- Acute toxicity: Imazalil is moderately
toxic by ingestion, with a reported oral LD50 of 227 to
343 mg/kg in rats [1,8]. The LD50 in dogs is greater than
640 mg/kg . The reported dermal LD50 is 4200 to 4880
mg/kg in rats, indicating slight toxicity . Test
animals have experienced symptoms such as excitation of
hair folicles (goose pimples), muscle incoordination,
reduced arterial tension, tremors, and vomiting .
Contact dermatitis has been noted in some cases in
sensitive individuals .
- Chronic toxicity: Rats fed imazalil
nitrate at dietary levels of up to 0.4 mg/kg/day for 14
weeks were not affected in appearance, behavior,
survival, food consumption, urinalysis, or tissue
composition. There were slight liver, body weight, and
bilirubin changes at higher doses . Groups of rats
fed up to 0.4 mg/kg/day for 6, 12, and 24 months did not
show compound or dose related effects on body weight
gain, food consumption, appearance, behavior, or survival
. Similar results were found in a dog study where
animals received up to 0.5 mg/kg/day for 2 years. The
liver showed some slight effects at the higher doses, but
all other measured and observed parameters were within
normal limits .
- Reproductive effects: In three separate
three-generation rat studies at low to moderate doses of
0.4 mg/kg/day, there was a trend to a lower number of
live births at the highest dose level. No differences
were noted in percent of pregnancies or duration of
pregnancy [3,41]. These data suggest that imazalil is
unlikely to cause reproductive effects under normal
- Teratogenic effects: None of the rat
studies mentioned above resulted in fetal abnormalities.
A mouse study at doses up to 4.8 mg/kg/day was also
negative. It is unlikely that imazalil is teratogenic
- Mutagenic effects: Dominant lethal
mutagenic effects were not evident in male and female
mice . Based on these data, it appears that imazalil
is not mutagenic.
- Carcinogenic effects: In a group of rats
given imazalil for 30 months at a dose of 5.0 mg/kg/day,
there were no increases in tumors compared to the
controls . This suggests that imazalil is
- Organ toxicity: Based on animal tests,
imazalil affects the nervous system and liver.
- Fate in humans and animals: Imazalil is
rapidly absorbed, distributed, metabolized, and excreted
by rats. Following a single dose of imazalil sulfate, 90%
was excreted in metabolized form within 96 hours .
Only 3% was eliminated via the feces in nonmetabolized
form, indicating almost complete absorption from the
gastrointestinal tract . At least four metabolites
are formed 48 hours after administration. Accumulation in
fatty tissue did not occur .
- Effects on birds: Both the mallard duck
and the Japanese quail are relatively insensitive to the
fungicide. The 8-day LC50 values in these birds range
from about 5500 to 6300 mg/kg/day . These values
indicate that the compound is practically nontoxic to
- Effects on aquatic organisms: Imazalil
is moderately toxic to fish. The LC50 for imazalil in
trout is 2.5 mg/L and in the bluegill sunfish is 3.2 mg/L
- Effects on other organisms: The compound
is non-toxic to bees .
- Breakdown in soil and groundwater:
Imazalil is highly persistent in the soil environment,
with a reported field half-life of between 120 and 190
days . A representative value is estimated to be 150
days for most soils . It is soluble in water, but
strongly bound to soils , and thus unlikely to pose a
risk to groundwater. In a plot where seven applications
were made at 14-day intervals, leaching was practically
nonexistent and accumulation did not appear to be a
- Breakdown in water: In acid to neutral
aqueous solutions, imazalil is stable for at least 8
weeks at 40 F. Decomposition occurs at elevated
temperatures and under the influence of light .
- Breakdown in vegetation: One week after
treated barley seed was sown in soil, about 76% of the
imazalil was in the adjacent soil and about 29% was in
the seedcoat. After 3 weeks, only 6% was in the green
plant parts. Under normal storage conditions, oranges
dipped in 2000 mg active ingredient/L and stored have
residues (89%) present as the parent compound. Only a
small amount of imazalil was present in the pulp, and
part of this may have resulted from handling during
peeling . Studies with apples gave similar results.
- Appearance: Imazalil is a slightly
yellow to brown solidified oil .
- Chemical Name: (+/-)-allyl
1-(2,4-dichlorophenyl)-2-imidazol-1-ylether ester 
- CAS Number: 35554-44-0
- Molecular Weight: 297.18
- Water Solubility: 1400 mg/L @ 20 C 
- Solubility in Other Solvents: s.s. in
hexane, methanol, toluene, benzene 
- Melting Point: 50 C 
- Vapor Pressure: 0.0093 mPa 25 C 
- Partition Coefficient: 3.8195 
- Adsorption Coefficient: 4000 
- ADI: 0.03 mg/kg/day 
- MCL: Not Available
- RfD: 0.013 mg/kg/day 
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
Plant Protection Division
1125 Trenton-Harbourton Road
Titusville, NJ 08560-1200
- Phone: 609-730-2607
- Emergency: Not Available
References for the information in this PIP can be found in
Reference List Number 10
information in this profile does not in any way replace or
supersede the information on the pesticide product labeling or
other regulatory requirements. Please refer to the pesticide