Safety
25
Safety Precautions
Warning Symbols
Visual warning symbols on pesticide labels indicate
the kind of harm that can result from pesticide misuse
or mishandling. They alert the user to the degree of
the hazard (by the shape of the border) and to the
type of hazard (by the centre picture).
Flammable The “fire” symbol is a warning that the
pesticide is flammable or easily ignited.
Keep the pesticide away from heat,
sparks or open flames. Do not smoke
while mixing or applying the product.
Explosive
The “exploding grenade” symbol
indicates that the pesticide can
explode, e.g. pesticide in pressurized
cans. Explosive conditions may also
be created by using Roundup or
Rustler (glyphosate) in a galvanized
steel spray tank.
Corrosive
The “corroded hand” symbol indicates
that the pesticide is corrosive to the
skin and eyes. The chemical is either
acid or alkali (caustic) and can burn
the skin. Protect the skin and eyes
when using these products.
Poisonous The “skull and crossbones” symbol
warns that the chemical is poisonous
if taken into the body. Keep the
product out of reach of children. Use
the appropriate safety measures when
dealing with poisonous products.
Pesticide Toxicity, Hazard and Risk
The terms “toxicity,” “hazard” and “risk” do not all
have the same meanings. Users of pesticides should
understand the difference in meanings among
these terms.
Pesticides vary in toxicity or the degree of being
poisonous. How poisonous a pesticide is depends
on its inherent chemical and physical properties.
The relative hazard of a pesticide depends on the
toxicity of the pesticide, the dose received and the
length of time exposed. No hazard exists when the
pesticide container is sealed, but once the seal is
broken and the pesticide is handled, exposure can
occur, and a hazardous situation is created.
Risk of exposure is a function of how an individual
handles the product. Although the hazard may be
the same whenever a pesticide is being poured into
the spray tank, the risk is different if one person
wears a hard hat, goggles, respirator, nitrile gloves,
waterproof apron and neoprene or rubber boots and
the other person wears none of these. A knowledge
of the toxicity of a product and the potential for
personal exposure can be used to lower the risk of
exposure. The user can control the risk by carefully
managing the hazard. Even when highly toxic
pesticides are used, if the degree of exposure is kept
low enough, the risk can be kept at an acceptable
level. The toxicity of the pesticide can’t be changed,
but the risk can be managed.
LD
50
values are used to rate the toxicity of the
pesticides. The LD
50
is an abbreviation for the dose
(
expressed in milligrams per kilogram of body weight
of the test animal) that is lethal to 50 per cent of the
The following table relates the oral LD
50
value (mg/kg) of a pesticide to its toxicity symbol.
LD
50
greater than
2,500
mg/kg indicates
very low toxicity
LD
50
1,000 - 2,500
mg/kg
indicates low
toxicity
LD
50
500 - 1,000
mg/kg
indicates moderate
toxicity
LD
50
less than 500 mg/kg
indicates high
toxicity