dinoseb (Premerge, Dinitro) Herbicide Profile 4/87
CHEMICAL NAME: 2-sec-butyl-4,6-dinitrophenol (56)
TRADE NAME(S): Premerge, Vertac Dinitro Weed Killer, Dynamyte 3,
Dow General Weed Killer, Dow Selective Weed Killer
FORMULATION(S): Premerge 3 Dinitro Amine Herbicide, Vertac Dinitro
Weed Killer, Dynamyte 3 (all formulated as the
alkanolamine salt of dinoseb and contain the
equivalent of 0.36 kg (3 lb) of dinoseb per l
(gal); Dow General Weed Killer, 0.6 kg/l (5 lb
dinoseb/gal) as the free phenol; Dow Selective Weed
Killer, 0.12 kg (1 lb) ammonium salt of dinoseb/l
(gal); various formulations alone or in
combinations with other weed killers such as
naptalam are available from formulators (58).
TYPE: Nitrophenolic herbicide
BASIC PRODUCER(S): Tifa Ltd. Vertac Chemical Corp.
Tifa Squiare 5100 Poplar
50 Division Ave. Memphis, TN 38137
Millington, NJ 07946
STATUS: Restricted use. On October 7, 1986, the EPA
issued an emergency suspension and cancellation
that prohibits the sale, distribution, and use of
all dinoseb products. This action was taken
and based primarily on evidence that dinoseb
exposure poses a risk of birth defects, male
sterility, and acute toxicity to agricultural
workers. This order became effective immediately
on the above date.
*** NOTICE ***
April 22, 1987
What is the Status Nationally?
The EPA ordered an emergency suspension of all registered
products containing dinoseb or any of its salts on October 14, 1986.
This action prohibited all sale, distribution, and use of dinoseb
products. Also at the same time, EPA issued an intent to cancel the
registrations of all pesticide products containing dinoseb and to deny
all pending applications for any product containing dinoseb.
The decision to suspend dinoseb was related to new data
submitted to EPA. The new data, the EPA administrator said, showed
1. Dinoseb is a developmental toxicant in laboratory
2. Dinoseb affects the reproductive system of male
3. Acute toxicity of dinoseb is achieved through exposure
to relatively low doses by both the oral and dermal
routes when compared with other pesticides.
4. The use of dinoseb also poses hazards to wildlife.
Recently, the EPA has allowed three states (Washington, Idaho
and Oregon) to use dinoseb as a result of hearings. These hearings
were primarily requested by processors (the Agriculture Department
requested hearings for Oregon) and demonstrated new benefit data,
or that the EPA underestimated the economic situation as a result of
the suspension of dinoseb.
What is the Status in New York?
All pesticide formulations containing dinoseb are suspended.
No one can sell, distribute, transport, or use pesticide formulations
containing dinoseb. The Department of Environmental Conservation
(DEC) has quarantined most suppliers and applicators possessing
Dr. Robin Bellinder and the Chemicals-Pesticides Program
submitted an emergency exemption, Section 18 request, on March
20, 1987 to the DEC for the use of dinoseb to control broadleaf weeds
in peas and beans (snap, dry, and lima). The request is still at DEC
and and has not been formally sent to EPA.
What About Reimbursement and Disposal?
Procedures for requesting indemnification (compensation) and
disposal for pesticide products containing dinoseb products were
published in the April 15, 1987 Federal Register (enclosed).
The right of indemnification extends to "any person" who has
suffered economic loss as well as those who owned products at the
time of suspension. Indemnification claims for dinoseb products
must be filed with the EPA no later than July 14, 1987. Follow their
procedures in the Federal Register Notice ( please note that form(s)
must be obtained and filled out, so don't wait until the last minute).
Disposal information can be found on page of 12357 of the
Federal Register notice. The EPA is encouraging registrants and
suppliers to take back suspended or canceled dinoseb products.
For more information regarding dinoseb, please contact the
PRINCIPAL USES: The phenol form (Vertac General Weed Killer) is
used as a general contact herbicide in orchards, vineyards, forage
legumes, and for killing potato vines and desiccating seed crops to
facilitate harvest. The ammonium salt (Vertac Selective) is used as a
selective contact herbicide in alfalfa, clover, birdsfoot trefoil,
onions, garlic, peas, and small grains. Alkanolamine salts such as
Premerge 3 are applied to kill germinating seeds contained in the upper
soil surface layers in preemergence treatments and also in early
postemergence and directed sprays in numerous crops. Drexel Dynamyte 3
for use on lentils (56).
APPLICATION METHOD(S): Preplant, preemergence, postemergence and directed
postemergence applications possible depending upon weed problem, crop,
and dinoseb formulation (58).
Important Weeds Controlled: Effective on most small annual seedlings,
Spraying is most effective at relatively high temperatures. Control
should last from between 3-6 weeks (8b).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C10 H12 N2 O5 (62)
MOLECULAR WEIGHT: 240.2 (62)
PHYSICAL STATE: Orange solid (pure compound); orange-brown solid
(technical product, 95-98% pure) (62).
ODOR: Pungent odor (pure compound) (58)
MELTING POINT: 38-42 C (pure compound); 30-40 C (technical
BOILING POINT: Not determined. Flash point 177 C (pure compound)
VAPOR PRESSURE: 1 mmHg at 151.1 C; 20 mmHg at 217.3 C (pure
SOLUBILITY: 0.0052 g/100g water at 25 C (pure compound) (58).
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: NA
NIOSH RECOMMENDED LIMIT: NA
ACGIH RECOMMENDED LIMIT: NA
A. ACUTE TOXICITY
DERMAL: Staining of skin and minor irritation by very small
amounts. Rapid absorption - The dinoseb LD50 value for
guinea pigs is in the range of 100 to 200 mg/kg. The
LD50 value for skin adsorption in rabbits of 3 dinoseb
formulations are: 170 mg/kg for Premerge 3 Dinitro
Amine Herbicide, 75 mg/kg for Dow General Weed Killer,
and 212 mg/kg for Dow Selective Weed Killer (58).
ORAL: LD50 = 58 mg/kg (rat) (58).
INHALATION: Dusts may be irritating and may cause serious
EYES: Mild to moderate irritation expected (58).
B. SUBACUTE AND CHRONIC TOXICITY:
Fed to rats for 5 to 13 days as 0.05% of diet; caused rapid
emaciation, slight kidney and liver effects, and death (58).
Rats - 6 months:
0.01% in diet - no effects.
0.02% in diet - growth depression without mortality.
In a 91-day dog study there was no effect at 100 ppm in the diet
which is approximately 4 mg/kg per day (58).
In 180-day feeding trials rats receiving 100 mg/kg diet suffered
no ill effect (62).
IV. ENVIRONMENTAL CONSIDERATIONS
Behavior In Or On Soils
1. Adsorption and leaching characteristics in basic soil types:
Dinoseb is not tightly adsorbed on most agricultural soils. It
can leach in porous, sandy soils; but experiments have shown
that for normal temperature zone rainfall and infiltration
rates, it should not be leached from the top foot of soil by
rainfall in the first year after application, during which time
it is subjected to soil microbial degradation.
2. Microbial breakdown: There is no buildup in soil and microbial
breakdown has been demonstrated.
3. Loss from photodecomposition and/or volatilization: Some losses
via steam distillation under specific conditions of soil
acidity, high temperatures, and surface soil moisture.
4. Resultant average persistence of phytotoxicity at recommended
rates: Two to 4-weeks under average conditions of use (58).
1. General toxicity to wildlife and fish:
a. Toxicity to fish - dinoseb is highly toxic to fish. After 24
hr of exposure, goldfish showed no effect at 0.1 ppm; but at
0.4 ppm, all died. Since dinoseb is not used in aquatic
areas, there is little or no practical hazard to fish as long
as direct contamination of lakes and streams is avoided.
b. Five-day dietary studies with dinoseb show that it is
moderately toxic to birds. The LC50 of dinoseb to ring-necked
pheasant is 515 ppm and to Japanese quail is 409 ppm.
c. Under actual use conditions, the practical hazard of dinoseb
to birds and other wildlife is very low. Since dinoseb is a
potent contact herbicide, vegetation is neither attractive nor
palatable to wildlife soon after treatment. Residues on
treated vegetation degrade quite rapidly and are very low by
about 3 weeks after spraying. No proven cases of injury to
birds or other wildlife have occurred during wide-scale
commercial use of dinoseb for over 20 years.
Toxicological studies on laboratory animals, certain
alkyldinitrophenols used in agriculture. The Dow Chemical Co.,
Dinitrophenol -- toxicological information and suggestions regarding
treatment for persons swallowing herbicides containing
dinitrophenol. The Dow Chemical Company, Midland, Michigan (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
FREQUENT SYMPTOMS AND SIGNS OF POISONING:
YELLOW STAINING of skin and hair often signify contact with a
nitrophenolic chemical. Staining of the sclerae and urine indicate
absorption of potentially toxic amounts. PROFUSE SWEATING, HEADACHE,
THIRST, MALAISE, and LASSITUDE are the common early symptoms of
poisoning. WARM, FLUSHED SKIN, TACHYCARDIA, and FEVER characterize a
serious degree of poisoning. APPREHENSION, restlessness, anxiety,
manic behavior, or unconsciousness reflect severe cerebral injury.
CONVULSIONS occur in the most severe poisonings. Cyanosis, tachypnea
and dyspnea result from stimulation of metabolism, pyrexia, and tissue
anoxia. Weight loss occurs in persons chronically poisoned at low
SKIN CONTACT: Wash contaminated skin and hair promptly with soap
and water, or with water alone if soap is not available (25).
INGESTION: Induce vomiting by giving an emetic and repeat until
vomit is clear. Then give two teaspoonfuls of baking soda in a glass
of water. Send for a physician immediately (58).
INHALATION: If any illness occurs due to inhalation of dust or
spray mists, remove the person to fresh air and call a physician (58).
EYE CONTACT: Flush chemical from eyes with copious amounts of
clean water (25).
NOTES TO PHYSICIAN:
1. IN EVENT OF SYSTEMIC POISONING:
A. REDUCE ELEVATED BODY TEMPERATURE BY PHYSICAL MEANS.
Administer sponge baths and cover victim with low-temperature
blankets. In fully conscious patients, administer cold,
sugar-containing liquids by mouth as tolerated.
B. Administer OXYGEN continuously by mask to minimize tissue
C. Unless there are manifestations of cerebral edema, administer
INTRAVENOUS FLUIDS at maximum tolerated rates to enhance
urinary excretion of toxicant and to support physiologic
mechanisms for heat loss. IN the presence of CEREBRAL EDEMA,
intravenous FLUIDS must be administered very CAUTIOUSLY to
avoid increasing the cerebral injury. Monitor fluid balance,
blood electrolytes and sugar, adjusting IV infusions to
stabilize electrolyte concentrations. Follow urine contents
of albumin and cells. Follow serum alkaline phosphatase, GOT,
and LDH to evaluate liver injury.
D. Administer SEDATIVES, if necessary, to control apprehension,
excitement, and/or convulsions. Although not previously used
in this type of poisoning, DIAZEPAM (Valium) should help:
adult dose, 5-10 mg slowly IV, or IM (deep); child's dose, 0.1
mg/kg. Repeat every 2-4 hours as needed. Amobarbital or
pentobarbital may be needed. Dose in adults: 200 mg, IM or
slowly IV, every 4-6 hours; child's dose: up to 5 mg/g.
CAUTION: Be prepared to counteract respiratory depression and
hypotension which may follow administration of
anticonvulsants and sedatives.
2. If toxicant has been INGESTED, evacuate the stomach and intestine.
A. If victim is alert and respiration is not depressed, give
SYRUP OF IPECAC, followed by 1-2 glasses of water, to induce
vomiting (adults 12 years and older: 30 ml; children under
12: 15 ml).
CAUTION: OBSERVE victim closely AFTER administering IPECAC.
If consciousness level declines, or if vomiting has
not occurred in 15 minutes, immediately INTUBATE,
ASPIRATE, and LAVAGE the stomach.
Following emesis, have victim drink a suspension of 30-50 gm
ACTIVATED CHARCOAL in 3-4 ounces of water to bind toxicant
remaining in the gastrointestinal tract.
B. IF VICITM IS NOT FULLY ALERT, empty the stomach immediately by
INTUBATION, ASPIRATION, and LAVAGE, using isotonic saline or
5% sodium bicarbonate. Because these pesticides are usually
dissolved in petroleum distillates, emesis and intubation of
the stomach involve serious risk that solvent will be
aspirated, leading to chemical pneumonitis. For this reason:
(a) If victim is unconsciousa or obtunded and factilities are
at hand, insert an ENDOTRACHEAL TUBE (cuffed, if
available) prior to gastric intubation.
(b) Keep victim's HEAD BELOW LEVEL OF THE STOMACH and turned
to the left, during intubation and lavage (Trendelenburg,
or left lateral decubitus, with head of table tipped
(c) ASPIRATE PHARYNX as regularly as possible to remove
gagged or vomited stomach contents.
(d) After aspiration of gastric contents and washing of
stomach, instill 30-50 gm of ACTIVATED CHARCOAL in 3-4
ounces of water through the stomach tube to limit
absorption of remaining toxicant. Do NOT instill cream,
milk, or other materials containing vegetable or animal
fats, as these are likely to enhance absorption.
C. If bowel movement has not occurred in 4 hours, and if patient
is fully conscious, give SODIUM SULFATE as a cathartic: 0.25
mg/kg body weight in 1-6 ounces of water. Magnesium sulfate
and citrate are equally suitable unless renal function is
impaired; retention of magnesium may depress CNS function and
alter myocardial irritabiity.
3. DO NOT administer atropine, aspirin, or other antipyretics to
control fever. Animal tests indicate that aspirin enhances,
rather than reduces, the toxicity of nitrophenolic and
4. During convalescence, administer high-calorie, high-vitamin diet
to facilitate repletion of body fat and carbohydrate.
5. Discourage subsequent contact with the toxicant for at least 4
weeks, to allow full restoration of normal metabolic processes.
6. HEMODIALYSIS and HEMOPERFUSION may be considered in severe
poisonings by aromatic nitro-compounds, although most phenols are
extensively bound to plasma proteins. EXCHANGE TRANSFUSION is
another option in poisonings characterized by impaired renal
function. So long as renal and liver functions are intact, these
compounds are efficiently excreted (25).
VI. FIRE AND EXPLOSION INFORMATION
Premerge 3 Dinitro Amine Herbicide - flammable (flash point
29.4 C, TCC)
Dow General Weed Killer - flammable (flash point 15.6 C TCC)
Dow Selective Weed Killer - flammable (flash point 18.9 C TCC) (58)
Premerge 3 - compatible with hard water.
Dow General Weed Killer - forms loose emulsions in all types of
water; needs mechanical agitation.
Dow Selective Weed Killer - compatible with hard water.
Formulations are noncorrosive to equipment if cleaned after use (58)
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: Do not get in eyes, on skin, or on clothing. Do
not take internally. Wash thoroughly with soap and water after
handling and before eating or smoking. Avoid breathing spray mist or
vapors. Do not store near heat or open flame. This product is toxic
to fish and wildlife. Birds and other wildlife in treated areas may be
killed. Keep out of lakes, streams, or ponds. Do not apply where
run-off is likely to occur. Do not apply when weather conditions favor
drift from areas treated (40b).
PROTECTIVE CLOTHING: Wear suitable protective equipment such as
chemical workers goggles, rubber or plastic gloves and rubber or
plastic apron while pouring and transferring the concentrated product
and at other times when contact is likely. Wear protective clothing
such as long sleeved shirt and long legged pants or coveralls while
mixing or spraying. Do not wear contaminated clothing or shoes (40b).
PROTECTIVE EQUIPMENT: To avoid breathing spray mist, wear a mask or
respirator of a type recommended by NIOSH or MSHA. Keep respirator
clean. Wash throughly and change cartridge as necessary (40b).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
X. LITERATURE CITED
8b. Thomson, W.T. 1981. Agricultural chemicals - book 2:
herbicides. Revised ed. Thomson Publications, Fresno, CA.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
40b. The Dow Chemical Company. 1980. Specimen label: Premerge 3.
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.