Chemical Properties
Light-yellow crystals. Insoluble in water; soluble in most organic
solvents. Decomposes in alkaline solutions.
Uses
Insecticide; acaricide.
General Description
Light yellow crystalline powder with an aromatic odor. Used as an insecticide for cotton and an acaricide.
Air & Water Reactions
Insoluble in water. Hydrolyzed by alkali [EPA, 1998].
Reactivity Profile
Organophosphates, such as EPN, are susceptible to formation of highly toxic and flammable phosphine gas in the presence of strong reducing agents such as hydrides. Partial oxidation by oxidizing agents may result in the release of toxic phosphorus oxides.
Health Hazard
EPN may be fatal if swallowed. It is poisonous if inhaled and extremely hazardous by skin contact. Repeated exposure may, without symptoms, be increasingly hazardous. The estimated fatal oral dose is 0.3 grams for a 150 lb. (70 kg) person.
Fire Hazard
(Non-Specific -- Organophosphorus Pesticide, n.o.s.) EPN may burn but does not ignite readily. Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Avoid strong oxidizers. Hydrolyzed by alkali.
Hazard
A cholinesterase inhibitor, absorbed by
skin, use may be restricted. Questionable carcinogen.
Potential Exposure
EPN is used in preparation of emulsifiable, granular or wettable powder insecticides for cotton.
A potential danger to those involved in the manufacture,
formulation and application of this material.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Speed in removing material from skin
is of extreme importance. Shampoo hair promptly if contaminated. Seek medical attention immediately. If this
chemical has been inhaled, remove from exposure, begin
rescue breathing (using universal precautions, including
resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit.
Shipping
UN2783 Organophosphorus pesticides, solid,
toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1;
Labels: 6.1-Poisonous materials, Technical Name Required.
UN3018 Organophosphorus pesticides, liquid, toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
Incompatibilities
Contact with oxidizers may cause the
release of phosphorous oxides. Contact with strong reducing agents, such as hydrides; may cause the formation of
flammable and toxic phosphine gas. Contact with alkalies
causes decomposition (hydrolysis) producing p-nitrophenol.
Description
EPN is a light yellow crystalline solid with anaromatic odor (as a pesticide) or a brown liquid above36℃. Molecular weight = 323.32; Freezing/Meltingpoint = 36℃; Vapor pressure = 3.4 * 10 -7 mmHg at 20℃.Hazard Identification (based on NFPA-704 M RatingSystem): Health 4, Flammability 1, Reactivity 0. Insolublein water.
Waste Disposal
EPN plant wastes are treated
by preaeration, activated sludge treatment; recycle, chlorination and final polishing where additional natural biological stabilization occurs. EPN is also relatively rapidly
hydrolyzed in alkaline solution to benzene thiophosphoric
acid; alcohol and p-nitrophenol and soil burial with alkali
may be used. For large quantities, however, incineration is
recommended. In accordance with 40CFR165, follow
recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following
package label directions or by contacting your local or federal environmental control agency, or by contacting your
regional EPA office.
Physical properties
Yellow to brown crystalline powder with an aromatic-like odor.
Definition
ChEBI: EPN is an organic phosphonate, a phosphonic ester and an organothiophosphate insecticide. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, an acaricide and an agrochemical.
Agricultural Uses
Insecticide: Banned for use in the EU. All registered uses of EPN
in the U.S. were canceled by the U.S. EPA on August 31,
1988. Effective June 9, 1993, the U.S. EPA announced the
revocation of all tolerances for residues of the insecticide
Trade name
NIAGARA®[C]; PIN®; SANTOX®;
TRIPLE KILL T®[C]; VETO®[C]
Environmental Fate
Biological. From the first-order biotic and abiotic rate constants of EPN in estuarine
water and sediment/water systems, the estimated biodegradation half-lives were 6.2 and
9.2 days, respectively (Walker et al., 1988).
Soil. Though no products were reported, the half-life in soil is 15–30 days (Hartley
and Kidd, 1987).
Photolytic. EPN may undergo direct photolysis since the insecticide showed some
absorption when a 1,4-dioxane was irradiated with UV light (l >290 nm) (Gore et al.,
1971).
Chemical/Physical. On heating, EPN is converted to the S-ethyl isomer (Worthing and
Hance, 1991). Releases toxic fumes of phosphorus, nitrogen and sulfur oxides when heated
to decomposition (Sax and Lewis, 1987; Lewis, 1990). Rapidly hydrolyzed in alkaline
solutions to p-nitrophenol, alcohol and benzene thiophosphoric acid (Sittig, 1985).
Metabolic pathway
EPN is degraded and deactivated in soil, plants and animals by a series
of hydrolytic, dealkylation and oxidative desulfuration steps, ultimately
to give phenylphosphonate. The metabolic pathway may or may not
proceed via activation to the oxon, which is not usually detected in
appreciable quantities as it metabolically unstable. A detoxification reaction
via reduction of the nitro group to afford amino-EPN has been shown
to take place in anaerobic soil, bacteria and animals. Uncommonly for
organophosphates, hydroxylation of the phenyl ring also occurs in rats
and hens.
storage
Color Code—Blue: Health Hazard/Poison: Storein a secure poison location. Prior to working with EPN youshould be trained on its proper handling and storage. Storein tightly closed containers in a cool, well-ventilated areaaway from oxidizers.
Degradation
EPN is hydrolysed by alkali to yield 4-nitrophenol (2). The half-lives at
pH values 4 and 7 were 70 days and 22 days, respectively. When heated in
a sealed tube it was converted to the isomeric S-ethyl O-4-nitrophenyl
phenylphosphonothioate (3) (PM).
