napropamide (Devrinol) Herbicide Profile 2/85
CHEMICAL NAME: 2-(a-Naphthoxy)-N,N-diethylpropionamide (56)
TRADE NAME(S): Devrinol (56)
FORMULATION(S): Emulsifiable concentrate (2-E), wettable powder
(50%), and 10% granules (56).
BASIC PRODUCER(S): Stauffer Chemical Co.
Agricultural Chemical Div.
Westport, CT 06881
STATUS: General use
PRINCIPAL USES: Control of several grass and broadleaf weeds in
orchards and vineyards. Also effective for weed control in direct
seeded tomatoes, strawberries, tobacco, peppers, ornamentals, and other
Napropamide is registered for use on established or newly planted
almonds, apricots, cherries, grapes, nectarines, oranges, peaches,
plums, prunes, and tomatoes. It has been used for several years on
oilseed rape in Europe. Other tolerant crops include asparagus
(established), peppers, broccoli, Brussel sprouts, cabbage, Chinese
cabbage, cauliflower, collards, English pea, Irish potatoes, eggplant,
peanuts, radish, safflower, sunflower, tobacco, turnip, and watermelon.
Sensitive crops include wheat, barley, and milo (58).
APPLICATION METHOD(S): Napropamide may be applied to the soil surface
preemergence to the weeds in orchards where a lot of rainfall occurs
soon after application. For the best results, it should be incorporated
in the soil to a depth of 2.5 to 5 cm (1 to 2 inches) (58).
Important Weeds Controlled: Bromes, wild barley, cupgrass, annual
bluegrass, crabgrass, barnyardgrass, prickley lettuce, filaree,
groundsel, chickweed, fiddleneck, knotweed, lambsquarters, malva,
pigweed, purslane, sowthistle and others (8b).
Weeds not controlled include bindweed, annual morning glory,
mustards, nightshade, sunflower, and turkey mullein (8b).
A long-lasting compound which will give season-long weed control
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C17 H21 NO2 (62)
MOLECULAR WEIGHT: 271.4 (62)
PHYSICAL STATE: White crystals (pure compound); brown solid
(technical product) (58).
The technical grade is 92-96% pure (62).
MELTING POINT: 74.8 - 75.5 C (pure compound) (58); 68-70 C
(technical product) (29m).
VAPOR PRESSURE: 0.004 um at 25 C (pure compound) (58)
SOLUBILITY: 73 ppm water at 20C (pure compound) (58)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: LD50 = >4640 mg/kg (rabbit); it is not a primary skin
ORAL: LD50 (male rat) = >500 mg/kg (technical product); >4640
mg/kg (50 WP); >5000 mg/kg (10G) (56).
INHALATION: LC50 = >9.5 mg/l/hr (50W) (58)
EYES: It is not a primary eye irritant (62).
B. SUBACUTE AND CHRONIC TOXICITY:
Daily ingestion by mice of 30, 60, 120, 240 and 480 mg/kg/day for
six weeks in a feeding study resulted in no compound related changes in
general behavior, survival, appearance, body weight or food
Daily ingestion by beagle dogs of 16, 40 and 100 mg/kg/day for 13
weeks in a feeding study resulted in no compound related changes in
survival, body weight, histopathology, physical observations,
hemograms, plasma, glucose, BUN, AP, SGOT, prothrombin time or
urinalysis. Increased liver weight was observed at 100 mg/kg/day.
SGPT was elevated at 100 and 40 mg/kg/day.
Daily ingestion of 13, 25, and 50 mg/kg/day for 13 weeks by rats
in a feeding study resulted in no compound related changes in survival,
body weight gain, food consumption, physical examination, plasma
glucose, SGPT and prothrombin time.
Daily ingestion by rats of 10, 30, and 100 mg/kg/day for 52 weeks
in a feeding study resulted in no compound related changes in clinical
signs, survival, clinical chemistry, hematology, urinalysis, tissue
mass incidence or gross pathology. Body weight gain and food
consumption were slightly lower for females in the 100 mg/kg/day group
(Devrinol Technical) (29m).
IV. ENVIRONMENTAL CONSIDERATIONS
Goldfish LC50 (96 hr) = >10.0 ppm (58).
Behavior In Or On Soils
1. Adsorption and leaching characteristics in basic soil types:
Napropamide was quite resistant to leaching in most mineral soils.
It leached downward about 2.5 cm (1 inch) in clay and silty clay
soils, about 5 cm (2 inches) in loam, and 20 cm (8 inches) in
loamy sand when 20 cm (8 inches) of water was applied to columns
of each soil type.
2. Microbial breakdown: Napropamide was slowly broken down by
microorganisms in the soil. In pure culture, a soil fungus
metabolized it quite rapidly (50% in 2 weeks).
3. Loss from photodecomposition and/or volatilization: Very little
if any loss occurred by volatilization from the soil surface.
However, under conditions of high sunlight intensity in the
summer, slightly over 50% loss by photodecomposition occurred
after 4 days on the soil surface. Under winter conditions the
loss was approximately 30% in 8 days.
4. Resultant average persistence at recommended rates: When
incorporated in moist loamy sand and loam soils at 21 to 32 C (70
to 90 F), the half life was 8 to 12 weeks (58).
V. EMERGENCY AND FIRST AID PROCEDURES
The chemical information provided below has been condensed
from original source documents, primarily from "Recognition and
Management of Pesticide Poisonings", 3rd ed. by Donald P. Morgan,
which have been footnoted. This information has been provided in
this form for your convenience and general guidance only. In
specific cases, further consultation and reference may be required
and is recommended. This information is not intended as a sub-
stitute for a more exhaustive review of the literature nor for the
judgement of a physician or other trained professional.
If poisoning is suspected, do not wait for symptoms to develop.
Contact a physician, the nearest hospital, or the nearest Poison
SKIN CONTACT: Immediately remove contaminated clothing under a
safety shower. Flush all affected areas with large amounts of water
for at least 15 minutes. Do not attempt to neutralize with chemical
agents. Obtain medical advice immediately (Devrinol Technical) (29m).
INGESTION: Immediately dilute the swallowed material by rapidly
giving large quantities of water or milk, if available, and induce
vomiting by gagging the victim with a finger or blunt object placed on
the back of the victim's tongue. Continue fluid administration until
vomitus is clear. Never give anything by mouth to an unconscious
person. Call a physician or the nearest Poison Control Center
immediately (Devrinol Technical) (29m).
INHALATION: Remove from contaminated atmosphere. If breathing
has ceased, clear the victim's airway and start mouth-to-mouth
artificial respiration, which may be supplemented by the use of a
bag-mask respirator, or a manually-triggered oxygen supply capable of
delivering 1 liter/second or more. If the victim is breathing, oxygen
may be administered from a demand-type or continuous-flow inhalator,
preferably with a physician's advice. Contact a physician immediately
(Devrinol Technical) (29m).
EYE CONTACT: Immediately flush the eyes with large quantities of
running water for a minimum of 15 minutes. Hold the eyelids apart
during the irrigation to ensure flushing of the entire surface of the
eye and lids with water. Do not attempt to neutralize with chemical
agents. Obtain medical attention as soon as possible. Oils or
ointments should not be used. Continue the irrigation for an
additional 15 minutes if the physician is not immediately available
(Devrinol Technical) (29m).
VI. FIRE AND EXPLOSION INFORMATION
GENERAL: Flash point 191 C (375 F) (58).
Devrinol Technical is not considered flammable but may support
combustion and may decompose under fire conditions to give off toxic
materials. Prevent human exposure to fire, smoke, fumes, or products
of combustion. Evacuate nonessential personnel from the fire area.
Maintain a safe distance from the fire and drum storage areas because
excessive heat may cause drums to rupture violently. Wear full face
self-contained breathing apparatus and impervious clothing (such as
gloves, hoods, suits, and boots made of rubber) (Devrinol Technical)
EXTINGUISHER TYPE: Use water, dry chemical, foam, carbon dioxide, or
halogenated extinguishing agents. High pressure water hose may spread
the product from broken containers increasing contamination hazards.
Use of contaminated buildings, areas, and equipment must be prevented
until they are properly decontaminated (Devrinol Technical) (29m).
Possible incompatibiities: None known. Noncorrosive (58).
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Stable for several years in packages (58).
Containers should be stored in a cool, dry, well-ventilated area.
Store away from flammable materials and sources of heat and flame. Do
not store near seeds, fertilizer or foodstuffs. Exercise due caution
to prevent damage to or leakage from the container (Devrinol 50 WP)
PROTECTIVE CLOTHING: Wear rubber gloves, protective clothing, and
safety glasses (58).
PROTECTIVE EQUIPMENT: Where adequate ventilation is not available and
there is a possibility of exposure to vapor or aerosol, inhalation
exposure can be controlled through the use of NIOSH-MESA approved
respirator with a particulate prefilter (Devrinol Technical) (29m).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
Make sure all personnel involved in the spill cleanup are aware of
the hazards associated with this material.
A small spill can be handled routinely considering the physical
and hazardous properties of the product as well as the location of the
spill. Use adequate ventilation to prevent inhalation contact. Wear
protective clothing to prevent skin and eye contact. Use the
following procedures for Devrinol Technical:
1. Sweep up the powder being careful not to create a dust.
2. Place sweepings in an open drum.
3. Generously cover the contaminated area with a common household
detergent (e.g. TIDE). Using a stiff brush, work the detergent
into the spill material using sufficient water to form a slurry.
Brush the slurry into cracks and crevices; and allow to stand for
2 to 3 minutes. Be careful to completely avoid skin or eye
contact. Do not splatter on one's self or bystanders.
4. Spread a suitable absorbent such as clay on the slurried liquid
and shovel the absorbed material into an open drum.
5. Repeat if necessary.
6. Flush the area with water, while observing proper environmental
7. Seal drum and dispose of contaminated material in an approved
Larger spills must be handled according to a predetermined plan.
For assistance in developing a plan, contact Stauffer's Agricultural
Chemical Division, Westport, CT 06880 (Devrinol Technical) (29m).
X. LITERATURE CITED
8b. Thomson, W.T. 1981. Agricultural chemicals - book 2:
herbicides. Revised ed. Thomson Publications, Fresno, CA.
29m. Stauffer Chemical Company, Agricultural Chemical Division. 1978.
Product safety information: Devrinol technical. Westport,
29n. Stauffer Chemical Company, Agricultural Chemical Division. 1979.
Product safety information: Devrinol 50-WP. Westport, CT.
56. Farm Chemicals Handbook, 70th ed. 1984. R. T. Meister, G. L.
Berg, C. Sine, S. Meister, and J. Poplyk, eds. Meister
Publishing Co., Willoughby, OH.
58. Weed Science Society of America, Herbicide Handbook Committee.
1983. Herbicide handbook of the weed science society of
America, 5th ed. Weed Science Society of America, Champaign,
IL. 515 pp.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.