Insecticides
409
• 
Safety - page 25 • First aid - page 33 • Resistance management - page 41
bicarbonate breaks down to form ammonia (a pungent, warning gas) and carbon dioxide (a fire suppressant). Within
1 - 4
hours, depending on temperature and humidity, the product begins to decompose and release phosphine. After
decomposition, there remains a grey-white dust composed almost entirely of non-poisonous aluminum hydroxide
with trace amounts of undecomposed aluminum phosphide. The dust is eliminated when raw agricultural
commodities are moved.
Expected results
The effectiveness of this product depends on the fumigation achieved by the release of phosphine gas. Therefore,
tightness of the area to be fumigated and temperature of the commodity are essential when determining dosage rates
and exposure rates. The tighter the bin and the warmer the temperature of the commodity, the lower the dosage
required and vice versa.
Restrictions
Aerate finished food for 48 hours before it is offered to the consumer.
Toxicity
Hydrogen phosphide gas is very toxic to all forms of animal life, and exposure to even small amounts should be
prevented. Poisoning results from ingestion or inhalation as hydrogen phosphide is not absorbed through the skin. It
is also insoluble in water, fats and oils.
Precautions
Protective equipment
It will be necessary to wear a gas mask if the treated area is entered prior to aeration. It is not necessary to wear a gas
mask when product is applied according to label directions. Wear gloves of cotton or other breathable material when
handling the product. Only open containers in open air and with the opening pointing away from your face. Wash
hands after use of the product.
Reduce gas hazards
Never
let tablets come in direct contact with liquid – this contact causes the immediate release of hydrogen
phosphide.
Never
open a container except for immediate usage.
Never
confine the product in small gas proof
enclosures such as plastic bags. Such confinement could cause the gas concentration to reach the lower flammability
level. Take precautions in areas where copper, brass or gold are present, as corrosion may occur.
Never
fumigate in
areas containing electronic or telephone equipment, photographic film or copy paper. Remove such items or protect
them from exposure to the gas. Hydrogen phosphide has great penetrating power, and gas may slowly seep through
concrete block walls. Hydrogen phosphide does not layer, but expands to fill the available space.
Symptoms of poisoning
Severity depends on concentration of hydrogen phosphide involved.
Mild poisoning
results in fatigue, nausea,
pressure or pain in the chest, ringing in the ears and uneasiness. Hydrogen phosphide is not a chronic poison, and
these symptoms will readily disappear with rest and fresh air.
Greater quantities of gas
produce such symptoms as
vomiting, stomach ache, diarrhea, disturbance in equilibrium and dyspnea (difficulty in breathing). Very high
concentrations quickly cause bluish-purple skin colour, agitation, poor muscle co-ordination, sub-normal blood
oxygen content, unconsciousness and death. Death can occur very quickly or be delayed several days as a result of
pulmonary edema and collapse, by paralysis of the central respiratory system. In cases of severe poisoning,
disturbance in liver and kidney function can also occur.
First aid
Should exposure to hydrogen phosphide be documented or suspected, remove patient from gas atmosphere to open
air.
Call a physician immediately
.
Have the patient lie down, keeping him warm and comfortable. Treat as for shock.
Make
no
antidotal use of fats, oil, butter or milk. Do
not
administer atropine as it is contraindicative. Begin artificial
respiration if breathing has ceased. When exposure to low concentrations of hydrogen phosphide has been
documented or suspected, the individual involved should rest for 24 hours, and under no circumstances should he
resume any work dealing with fumigation. If ingested, induce vomiting by touching the back of the throat with a
blunt object.
Storage
Tablets are received in resealable flasks. As long as flasks remain intact, the storage life of the product is unlimited.
Storage should be in a dry, locked, ventilated area and out of the reach of children and irresponsible persons.
Phostoxin (cont’d)