Pesticides — how to read the material

This is the first article in a series
by research scientist Shona Kelly
that will talk about pesticides in
tree nurseries and sawmills. In
this article Ms. Kelly, a research-
er at the Division of Occupa-
tional and Environmental Health
at the University of B.C.’s
Department of Healthcare and
Epidemiology, will define the
term pesticide, and explain how
to read a label or material safety
data sheet. In the second article
she will explain measures of tox-
icity, how pesticides enter our
body and protective equipment.
The third article will concen-
trate on the pesticides used by
tree nursery.workers. The fourth
and final article will examine the
anti-sapstain pesticides used in
sawmills,

ESTICIDES are legal poisons

— chemical substances used

to kill or control pests. I use

the phrase “legal poisons”

deliberately. Pesticides are in-
deed poisons — just as is everything
else in our environment. Even every-
day substances like table salt and
oxygen can be hazardous if we are
exposed to high doses. As a famous
man in the 14th century said (and I
paraphrase) — all things are toxic, it
is only the dose that matters.

In Canada, pesticides are legally
controlled substances. This means
their availability and use in Canada
are controlled by regulations. Agri-
culture Canada, in consultation with
Health and Welfare Canada, Environ-
ment Canada, and Fisheries and
Oceans Canada, decides which prod-
ucts can be sold in Canada. These
decisions are based on reviews of toxi-
cology tests, laboratory and field stud-
ies of the persistence of the product
and also the use for which the pesti-
cide will be applied. This last one
sounds obvious, but in Canada, unlike
the U.S., we do not bring in new,
relatively untested products when old,
well understood products are still effec-
tive. Sometimes problems associated
with a pesticide may take years to
discover and Agriculture Canada
tends to be more cautious than their
US. counterparts.

DEFINITION OF A PESTICIDE

In Canada the term pesticide
includes all the subgroups listed in
Table 1. The popular press tends to
refer to ‘pesticides and herbicides’ —
perhaps because herbicides are con-
sidered non-toxic. I just want to
remind you that paraquat is a herbi-
cide! Many people feel that biocide
(literally meaning ‘killer of life’) is a
better term than pesticide. The word
biocide more accurately describes that
fact that other forms of life besides
the target pests can be affected when

After being manufactured in a rela-
tively pure form, the pesticide is then
formulated. The formulation is the
form in which the pesticide is sold for
use or, to put it another way, the
pesticide is processed into a useable
form. Pesticides are formulated to
improve their properties of storage,
handling, effectiveness, or safety. This
does not include any dilution done by
a pesticide applicator at the applica-
tion site. Table 2 is a list, by no means
complete, of the different types of
formulations. The part of the prod-
uct that kills the pest is called the
“active ingredient,” the other parts of
the product are called “inert ingredi-
ents.” The words active and inert refer
only to the way the pesticide affects
the pest and not on how hazardous
they may be to other organisms like
humans. Don’t be intimidated by the
terminology used in this table. I’ve
included the information so that the

.« pesticide label becomes less intimi-

dating. For example, EC in a pesti-
cide name means the product is an
emulsifiable concentrate. WP means
it is a wettable powder.

READING A LABEL
Now, lets look at a label. The first
thing you must understand about a
label is that it is a legal agreement
between the purchaser and the manu-
facturer. By purchasing the product
you are agreeing to use the product as
indicated on the label. It is illegal to
use a pesticide product for any pur-
pose not described on the label. Prod-
ucts introduced to the market recently
tend to have better labels than prod-

ucts that have been available for a

long time. Agriculture Canada is work-

ing with manufacturers to improve all
labels but this takes time.

Now, lets look at the information
available on the label.

1. Trade Name — this is the “brand
name.” It does not often contain
the name of the active ingredient,
but the name may contain the let-

formulation. It is important that
you know the complete name
because closely related products
may have similar names but differ-
ent ingredients. Emulsifiable con-
centrates may contain toxic petro-
leum distillates while wettable
powders do not. The proper name
of a pesticide product is critical
when poisoning has occurred and
doctors are trying to treat the
patient.

. Guarantee — this gives the amount

and name of the active ingredient.
If the “inert” ingredients are toxic
they will often be listed here as
well.

. Pesticide Use — a statement which,

in a general way, describes what
the product is to be used for. For
example, Vision is a herbicide for
use in forestry.

. Marketing Code — this describes
who can use the product.

— domestic is for untrained users in

the home and garden.

— commercial is for either Agricul-

ture or Industrial use and the
workers are expected to have had
some training.

— restricted is for application by

licensed applicators only and usu-
ally requires a special permit
issued by federal or provincial pes-
ticide regulators.

. Warning Symbols — are not
exactly the same as those used by
WHMIS but the underlying prin-
cipals are similar. A “stop sign” is
used on the most toxic pesticides,
a diamond-shaped sign warns of
moderate toxicity, and a “yield
sign” cautions of slight toxicity.
The symbols enclosed in these
signs may be a skull & crossbones
for poisonous products, a fire sym-
bol for flammable products, an
“exploding grenade” for potentially
explosive products, or a corroded
hand for corrhosive products.

. Precautions — state what protec-
tive equipment should be worn
while using the product. Older
labels tend to be vague here but
newer labels will even specify the
type of respirator cartridge or the
material that gloves should be

a,
cw -

© Research Scientist Shona Kelly

made from. For older products it is
best to contact the manufacturer
directly and find out what they
recommend.

. Directions for use — this is general

information on how the product is
to be applied to control the pest.
Most products have a separai
detailed application guide avail-
able. New ones should be obtained
each year as the information is
constantly being updated and
improved. Do not confuse the appli-
cation guide with the Material
Safety Data Sheet (MSDS).

. First Aid and Toxicological Infor-

mation — is a brief summary of
any poisoning symptoms. Much
more detailed information is avail-
able on the MSDS. The manufac-
turers should be contacted every
year to check for new versions of
the MSDS. The MSDS will also
have the most recent Emergency
phone number. There have been
many changes in the pesticide mar-
ket in Canada and phone numbers
found on products purchased more
than 6 months ago may not be
accurate.

|. Registration Number — this is the

Pest Control Products Act (PCP)
Number that is given to the prod-
uct by Agriculture Canada. Each

TABLE 2
PESTICIDE FORMULATIONS
Products such as bug bombs, Raid”.

Contain an insect attractant and may also
contain a pool of insecticide.

Usually pesticide-treated foods for control of
animals and birds.

Finely powdered dry
other finely powde:

aerosols
attractant traps

baits
dusts

emulsifiable concentrate

e

sticides mixed with
dry substances.

a pesticide is used.

ters EC or WP, which describe its

acaricide/miticide
algicide

animal repellant
animal toxicant
bactericide

bird repellant

bird toxicant/avicide
disinfectant

fish toxicant/piscicide
fungicide

herbicide

insect repellant
insecticide

materials preservative
molluscicide
nematicide

plant growth regulator
pruning paint
rodenticide
slimicide
wood preservative

PESTICIDE GROUPS — BY TYPE OF PEST KILLED

TABLE 1

kills mites and ticks

kills algae

repels animals but does not kill them
kills large animals like coyotes

kills or slows the growth of bacteria
repels bird but does not kill them
kills birds

same as a bactericide

kills fish

kills fungi

kills plants

repels insects but does not kill them
kills insects

e.g. mildew preventers in fabric

kills snails, slugs, clams, etc.

kills nematodes

increases or decreases plant growth
a physical barrier to protect tree wounds
kills rodents

kills slime, e.g. in swimming pools

flowable suspension
fumigants

granulars
impregnated material

oil solutions

slow release

soluble pellets

ultra-low volume
concentrates

wettable power

Oily solutions to which an emulsifier is added
to make them mixable with water.

A “pudding-like” product that flows easily into
the spray tank where it is mixed with water and
kept in suspension by constant mixing.
Pesticides that are gases at room temperature
and therefore can enter every crack and crevice
to kill pests.

Larger particles than dusts.

e.g.s. wood-preservative soaked clothes,

No-pest Strips’, flea collars.

Pesticide is dissolved in oil and is applied as an
oil spray. Water is NEVER added but kerosene
or diesel fuel may be used to dilute it.

e.g. micro-encapsulated pesticides, impregnat
resin strips.
Large blocks of pesticide impregnated solids that
are designed to dissolve in watér. Often available
to homeowners for use with a hose attachment.
Usually consists of the pesticide dissolved in a
minimum of solvent ada are applied without.
further dilution by special equipment that emits
an extremely fine spray.

A dust combined with a wetting agent to make
the mixing of the powder with water easier. They
don’t actually dissolve but are suspended in the
water and must be constantly stirred.

a
10/LUMBERWORKER/APRIL, 1992