EPN Chemical Profile 1/88
CHEMICAL NAME: Ethyl p-nitrophenyl thionobenzenephosphonate (31a)
DEC INGRED. CODE:
TRADE NAME(S): EPN (56)
FORMULATION(S): Wettable powders, granules, emulsifiable formulations
5 lb. EPN (5 lbs./gal.) (56)
TYPE: Organophosphate insecticide-miticide
BASIC PRODUCER(S): E.I. du Pont de Nemours and Co., Inc.
Wilmington, DE 19898
STATUS: Restricted use. RPAR issued 9/19/79; criteria possibly met or
exceeded: neurotoxicity. Final Notice of Determination and Decision
Document forwarded to Acting AA on June 30, 1983 (22).
No Special Review for EPN
On July 21, 1987, EPA issued a proposed decision not to initiate a
special review of EPN. The proposed decision was based on the fact that
there were no remaining viable registrations for EPN. Since EPA received no
comments on the proposed decision, the Agency has announced not to initiate a
special review. All registrations of technical EPN and formulated products
containing EPN have been voluntarily cancelled. The sale and use of existing
stocks will be allowed until August 31, 1988. After that date all remaining
stocks must be disposed of as permitted by state law (Federal Register,
PRINCIPAL USES: For control of insects such as European corn borer,
rice stem borer, bollworm, tobacco budworm, and boll weevil (56).
Important Pests Controlled: Rice stem borer, boll weevils, Oriental fruit
moth, cotton bollworms, plum curculio, fruit moths, peachtree borers,
mites, European cornborers, scale, budmoths, leafrollers, codling moths,
pear psylla, aphids, thrips, armyworms, leaf miners, Mexican bean
beetles, and many others (8a).
Acts similar to parathion only it is somewhat more persistant (8a).
II. PHYSICAL PROPERTIES
MOLECULAR FORMULA: C14 H14 NO4 P5 (62)
MOLECULAR WEIGHT: 323.3 (62)
PHYSICAL STATE: Light yellow crystalline powder (pure compound);
dark amber-colored liquid (technical product) (62).
MELTING POINT: 36 C (pure compound) (62)
VAPOR PRESSURE: 126 uPa at 25 C (pure compound) (62)
SOLUBILITY: Practically insoluble in water (pure compound) (62)
III. HEALTH HAZARD INFORMATION
OSHA STANDARD: 0.5 mg/m3 averaged over an 8-hour work shift (14)
NIOSH RECOMMENDED LIMIT: None established
ACGIH RECOMMENDED LIMIT: TWA (Time Weighted Average) = 0.5 mg/m3;
STEL (Short Term Exposure Level) = 2 mg/m3
(deleted); skin notation (15c).
A. ACUTE TOXICITY
DERMAL: LD50 = 230 mg/kg (male rat), 25 mg/kg (female rat)
LD50 = 420 mg/kg (rabbit) (56)
LD50 = 90-150 mg/kg (female rabbit); 30-50 mg/kg
(male rabbit) (31a).
Moderate to no skin irritation (31a)
ORAL: LD50 = 33-42 mg/kg (male rat); 14 mg/kg (female rat);
50-100 mg/kg (mouse); all dogs tested survived at 20
mg/kg, all were killed by 45 mg/kg (62).
INHALATION: LC50 = 0.076 mg/l (male rat); 0.024 mg/l
(female rat) (31a).
EYES: When treated with 0.1 ml of undiluted 44.8% liquid
formulation, unwashed eyes (rabbit) had moderate
conjunctival irritation and mild corneal opacity.
In all washed eyes the compound caused transient mild
conjunctival irritation and transient slight corneal
opacity. All eyes were normal within 2-7 days (31a).
B. SUBACUTE AND CHRONIC TOXICITY:
In 2-year feeding studies with rats, 75 ppm was a no-effect level
for females and 150 ppm a no-effect level for males; highest levels fed
(225 ppm for females and 450 ppm for males) retarded growth only. EPN
was not stored in vital organs or in depot fat. In one-year studies
with dogs (male and female), 2 mg/kg/day was a no-effect level. In a
21 month hen neurotoxicity study, no clinical signs of delayed
neurotoxicity were seen in hens fed 18 ppm. Delayed neurotoxicity was
seen at 54 ppm.
Ames Mutagenicity Study: Negative.
6 mg of EPN per day fed to human volunteers for 47 days produced
no effects. Daily dose of 9 mg for 56 days produced reversible
inhibition of blood cholinesterase. No neurotoxic effects were
IV. ENVIRONMENTAL CONSIDERATIONS
Moderately hazardous to birds, fish, and beneficial insects.
Hazardous to honey bees. Biological magnification unlikely. Injurious
to McIntosh and related varieties of apples (1).
Rainbow Trout LC50 (96-hr. exposure) = 190 ppb
Bluegill Sunfish LC50 (96-hr. exposure) = 80 ppb
Daphnia magna LC50 (48-hr. exposure) = 320 ppb
Bobwhite Quail LC50 (8-day feeding) = 437 ppm
Mallard Duck LC50 (8-day feeding) = 294 ppm
Bobwhite Quail LD50 = 220 mg/kg
Ringnecked Pheasant LD50 = 165 mg/kg
EPN showed little tendency to leach. Other evidence shows
ultraviolet degradation of EPN, which probably contributes to its rapid
environmental disappearance (31a).
Approximate Residual Period: 3 weeks on plants; 80 days on unexposed
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 BY ORGANOPHOSPHATE PESTICIDES
Symptoms of acute poisoning develop during exposure or within 12
hours (usually within four hours) of contact. HEADACHE, DIZZINESS,
WEAKNESS, INCOORDINATION, MUSCLE TWITCHING, TREMOR, NAUSEA, ABDOMINAL
CRAMPS, DIARRHEA, and SWEATING are common early symptoms. Blurred or
dark vision, confusion, tightness in the chest, wheezing, productive
cough, and PULMONARY EDEMA may occur. Incontinence, unconsciousness
and convulsions indicate very severe poisoning. SLOW HEARTBEAT,
salivation, and tearing are common. TOXIC PSYCHOSIS, with manic or
bizarre behavior, has led to misdiagnosis of acute alcoholism. Slowing
of the heartbeat may rarely progress to complete sinus arrest.
RESPIRATORY DEPRESSION may be fatal. Continuing daily absorption of
organophosphate at intermediate dosage may cause an INFLUENZA-LIKE
ILLNESS characterized by weakness, anorexia, and malaise (25).
SKIN CONTACT: Bathe and shampoo victim with soap and water if
there is any chance that skin and hair are contaminated (25).
INGESTION: If victim is alert and respiration is not depressed,
give Syrup of Ipecac, followed by 1-2 glasses of water to induce vomting.
Adults (12 years and over): 30 ml; children: 15 ml (25).
INHALATION: Remove from exposure and have patient lie down and
keep quiet. If patient is not breathing, start artificial respiration
immediately. Never give anything by mouth to an unconscious person
EYE CONTACT: Flush with water for 15 minutes and get medical
NOTES TO PHYSICIAN:
Administer ATROPINE SULFTE intravenously, or intramuscularly, if IV
injection is not possible.
In MODERATELY SEVERE poisoning: Adult dosage: 0.4-2.0 mg repeated
every 15 minutes until atropinization is achieved: tachycardia (pulse
of 140 per minute), flushing, dry mouth, dilated pupils. Maintain
atropinization by repeated doses for 2-12 hours or longer depending on
severity of poisoning.
Dosage for children under 12 years: 0.05 mg/kg body weight, repeated
every 15 minutes until atropinization is achieved. Maintain
atropinization with repeated dosage of 0.02-0.05 mg/kg.
SEVERELY POISONED individuals may exhibit remarkable tolernce to
atropine; two or more times the dosages suggested above may be needed.
Administer PRALIDOXIME (Protopam (TM)-Ayerst, 2-PAM) in cases of severe
poisoning in which respiratory depression, muscle weakness and
twitchings are severe.
Adult dosage: 1.0 gm intravenously at no more than 0.5 gm per minute.
Child's dose (under 12 years): 20-50 mg/kg (depending on severity of
poisoning) intravenously, injecting no more than half the total dose
Dosage of pralidoxime may be repeated in 1-2 hours, then at 10-12 hour
intervals if needed. In very severe poisonings, dosage rates may be
VI. FIRE AND EXPLOSION INFORMATION
To be developed.
Generally compatible except with Bordeaux and zinc-lime mixtures
VIII. PROTECTIVE MEASURES
STORAGE AND HANDLING: May be fatal if swallowed. Poisonous if inhaled.
Extremely hazardous by skin contact. Rapidly absorbed through skin.
Repeated exposure may, without symptoms, be increasingly hazardous. Do
not breathe vapor, do not get in eyes, on skin, on clothing. Use with
adequate ventilation. Keep away from heat and open flame. Keep
container closed. Store at 65-100 F (56).
PROTECTIVE CLOTHING: Wear clean heavy natural rubber gloves, rubber
boots, and clean waterproof or freshly laundered protective clothing
(coveralls, cap). Destroy and replace gloves frequently (31a).
PROTECTIVE EQUIPMENT: When mixing or otherwise handling, wear goggles
and a pesticide respirator jointly approved by the Mining Enforcement
and Safety Administration and by NIOSH (31a).
IX. PROCEDURES FOR SPILLS AND LEAKS
IN CASE OF EMERGENCY, CALL, DAY OR NIGHT
PESTICIDE TEAM SAFETY NETWORK/CHEMTREC
In case of spillage, cover with an absorbent such as soda ash,
lime, clay, or sawdust. Sweep up and bury. Wash area thoroughly with
strong lye solution; then flush with water (31a).
X. LITERATURE CITED
1. Harding, W.C. 1979. Pesticide profiles, part one: insecticides
and miticides. Univ. Maryland, Coop. Ext. Serv. Bull. 267.
8a. Thomson, W. T. 1976. Agricultural chemicals - book 1:
insecticides, acaricides, and ovicides. Revised ed. Thomson
Publ., Indianapolis, IN. 232 pp.
14. U. S. Department of Health and Human Services, National Institute
for Occuptational Safety and Health. 1981. Occupational
health guidelines for chemical hazards. F. W. Mackinson, R.
S. Stricoff, L. J. Partridge, Jr., and A. D. Little, Inc.,
eds. DHHS (NIOSH) Publ. No. 81-123. Washington, DC.
15c. American Conference of Governmental Industrial Hygienists. 1984.
TLVs: threshold limit values for chemical substances and
physical agents in the work environment and biological exposure
indices with intended changes for 1984-85. Cincinnati, OH.
22. U.S. Environmental Protection Agency, Office of Pesticide
Programs. 1983. June 1983 status report on rebuttable
presumption against registration (RPAR) or special review
process, registration standards and the data call in
programs. Washington, DC. 45 pp.
25. Morgan, D.P. 1982. Recognition and management of pesticide
poisonings, 3rd ed. U.S. Environmental Protection Agency,
Washington, DC. 120 pp.
31a. E. I. du Pont de Nemours and Co., Inc. 1983. Technical data
sheet for EPN. Wilmington, DE.
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.
62. The Pesticide Manual: A World Compendium, 7th ed. 1983. C.R.
Worthing, ed. The British Crop Protection Council, Croydon,
England. 695 pp.