WASHINGTON, D.C. 20460


Acknowledgments   	    1
Preface  	    1
Introduction 	    2
Pests	    2
  Insects  	    2
    Cockroaches 	    2
    Stored Product Pests	    2
    Domestic Flies 	    4
    Occasional Pests	    5
  Spiders  and Mites  	    6
  Centipedes  	    6
  Rodents  	    6
  Birds   	    6
Pest Control	    6
  Insects  	    6
  Spiders  and Mites  	    7
  Centipedes  	    7
  Rodents  	    7
  Birds   	    8
Pest Treatment Areas  in Food Plants	    8
  Incoming Ingredients and Materials
    Storage Areas	    8
  Processing and Packaging Areas	    9
  Finished Products Warehouse and
    Shipping  Areas  	    9
  Grounds  	    9
Pesticides  	    9
  Aerosols 	    9
  Liquids 	    9
  Dusts  	  10
  Granules  	  10
  Baits  	  10
  Fumigants  	  10
  Vapors  	  12

            EFA  ;:..:


This guide  was developed  by the University  of
Minnesota  under  U.S.  Environmental  Protection
Agency  (EPA)  contract  number  68-01-2651.  This
contract was issued by the Training Branch, Opera-
tions Division, Office of Pesticide Programs,  EPA.
The leader of this group effort was Phillip  K. Harein,
University of Minnesota. Editors  were Mary  Ann
Wamslcy.  EPA, and Donna  M.  Vermeirc, North
Carolina State University.

Contributors were:
Robert  Davis,  U.S. Department  of  Agriculture,
  Savannah, Georgia
William M.  Hoffman,  Environmental  Protection
  Agency, Washington,  D.C.
Darrell  Jones,  General  Mills,  Inc.,  Minneapolis,
Vernon  E.  Walter,  Terminix  International  Inc.,
  Memphis, Tennessee

Many representatives of  the food processing indus-
try and  food commodity associations reviewed and
commented on the  guide.
Federal  regulations establish general  and  specific
standards that you must  meet before you can use
certain pesticides. Your State will provide material
which you may study to help you meet  the general

This guide contains basic information to help you
meet the specific standards for pesticide applicators
in the food and feed industries. Because this guide
was prepared to cover the entire nation, some in-
formation important to  your State  may  not  be
included. The State agency in charge of your training
can provide the other materials you should study.

This guide will give you  information  about:
•  characteristics of common pests,
•  their  life cycles  and habits, and
•  how to control them.

 The control of pests in food plants (food manufac-
 turing, processing, and warehousing) requires a high
 degree  of  professionalism  combined  with  experi-
 ence and knowledge.

 • Food plants must continually  employ pest man-
   agement programs.
 * These programs must be  directed against pests in
   the immediate area, and against pests that  may be
   introduced from incoming materials.
 • These programs must respond  to daily needs  and
   be flexible to meet  emergency  pest control situa-
• Without  good  pest management,  contaminated
   products may result. Contamination  can cause
   serious health, financial, legal, and aesthetic prob-


 A variety of pests are found in food manufacturing
 plants. The type of pest  you will find depends on
both the geographic location of  the plant and the
type of food being processed.

Pests  may  damage,  destroy, or  contaminate proc-
 essed foods. They must be controlled to protect the
quality of  the product. The  presence or evidence of
pests  may  result in seizure of  products or other
 actions by Federal or  State  agencies.



Cockroaches contaminate  food with their droppings,
with their bodies, and with bacteria they carry. They
vary somewhat in appearance and  habits,  but in
• All cockroaches have chewing mouthparts.
• They seek cover in the daytime or when disturbed
   at night.
• All are flat, brownish or dark,  and fast-running.

The stages in the life cycle of a cockroach are:
• the egg, enclosed in  a capsule  which contains
   several eggs,
* several stages of  nymphs,  which look like  the
   adults but  are smaller  and have  no wings,  and
* the adult.
• Adults have  wings covering the entire abdomen.
• Reddish-brown.
• Adults 1 to I '-'2 inches long.
• Found  in  dark,  moist  areas  and may live  in

   Adults have wings covering entire abdomen.
   Tan with two dark stripes running lengthwise  on
   the area just behind the head.
   Often occur in  large numbers.
   Will eat almost any food consumed by man.
   Adults 1 to 11/2  inches long.
   More active than other cockroaches.

•  Female has small wings; male's wings cover about
   *'j  of the abdomen.
•  Shiny black, or very dark brown.
•  About 1 inch  long as an  adult.
•  Often lives in sewers  and enters buildings through
   American Cockroach       Oriental Cockroach

Stored Product  Pests

Beetles are important pests of stored food. Usually
both the larva  and  the adult  will feed on  food-
stuffs. Under ideal conditions they can have six or
more generations per year and quickly  become a
serious problem. Adults may have a pair of thin
wings covered by a  pair of thick,  hard  wings.

 The stages in  the life cycle of the beetle are:
 • egg,
 • larva,
 • pupa, and
 • adult.

   About VH inch long; dark brown.
   Pronounced snouts.
   Larvae arc  small, white,  legless grubs that feed
   and develop inside individual kernels of grain.
   May attack  grain prior to harvest and in storage.
   Rice weevil can fly;  granary weevil cannot fly.
        Granary Weevil
Rice Weevil
   Shiny dark brown or black beetle.
   Small and slender.
   Head turned downward; very strong mouthparts
   which can cut through wood.
   Adult is a strong flier.
   Larvae  feed  on  flour, grain  dust,  or broken or
   whole grain.
                       CONFUSED FLOUR BEETLE—RED FLOUR
                       • Elongated, flat adults,  about  Vs  inch long.
                       * Shiny, reddish-brown.
                       • Feed on stored foods such as flour,  cereal, nuts,
                         and  spices.
                       • Feed by scraping the surface of foods or eating
                         finely ground  material.
                       • Red flour beetle is  a strong  flier; confused flour
                         beetle cannot fly.
                       • The three segments  at the tip of the red flour
                         beetle's  antennae are enlarged. The antenna seg-
                         ments of the confused flour beetle enlarge grad-
                         ually toward the tip.
                                                     Red Flour Beetle
                       SAWTOOTHED GRAIN BEETLE-
                       MERCHANT  GRAIN BEETLE:
                         Elongated, flat adults, about V»  inch long.
                         Dark brown.
                         Adults have sawtooth-like projections on
                         of area just  behind the head.
                         Do not fly.
                         Feed on  almost all dried foods.
                                                     Saw-Toothed Grain Beetle
• Small, reddish-brown adults, usually less than Vs
  inch long.
• Head on adult bent down and not visible from
• Feed on dried plant and animal material.
• Cigarette beetle  can fly; drugstore beetle  seldom
• Wing covers  lined on  drugstore  beetle;  smooth
  on cigarette beetle.
    Cigarette Beetle
                       DERMESTID  BEETLES:
                       • Oval-shaped beetles  which feed on waste grain
                         or flour.
                       • Natural scavengers.
                       • Several species.
                       • Larvae are tapered, with head  at the  large end.
                       • Prominent bristles  or hair often found  at pointed
                         end of larva.
                       • Larvae feed  on dry grain dust, waste  matter, or
                          Khapra Beetle Adult
Khapra Beetle Larva

                                                      Mediterranean Flour Moth
Moths cause damage by:
• eating food,
• contaminating food to the point where  it cannot
   be consumed by  humans, and
• webbing food with so  much  silk  that  mill ma-
   chinery may be clogged.  Large populations may
   lead to microorganism  problems.

The stages in the life cycle of the moths are:
• egg,
• larva,
• pupa, and
• adult.

•  Adults  have  four wings;  about  '/2  inch  wing-    WAREHOUSE MOTH:
•  Forewings are pale yellow.  Hind wings are gray
   and pointed.
   Larvae  develop within whole kernels of grain.
   May attack grain before harvest  as well  as  in
   Pupa found inside grain.
   Six to  seven  generations per year.
   When they emerge, they leave a round flap over
   the hole in the grain.
                                                       Front wings are gray with dark wavy lines.
                                                       Adults rest with head and thorax held high.
                                                       Larvae feed on surface of food, and  spin large
                                                       amounts  of silk in and over it.
                                                       Three to four generations per year.
                                                       Larvae leave feeding area to pupate.
                                                       Prefers flour but infests wheat, bran, nuts, choc-
                                                       olate, seed, beans, and dried fruits.

                                                    • Adult's forewings are gray.
                                                    • They fly in a series of quick darts.
                                                    • Habits similar to the Mediterranean Flour Moth.
                                                    • Larvae striped  with a  series of brown or .purple

                                                    Domestic Flies
   Angoumois Grain Moth
  Adults  have four wings, with a  wingspread of
  about l/2 inch.
  Forewings have a coppery color on the outer two-
  thirds and whitish gray near the body.
  Larvae  spin large amounts of silk  in and over
  Larvae  may leave food and  crawl over adjacent
  Five to six generations per year.
  Prefers  flour but feeds on many raw and proc-
  essed dry foods.
   Indian Meal Moth
• Adults  have four wings, with a  wingspread of
  about % inch.
Most flies have one pair of wings as adults. The
larvae are called  maggots and  have the head  at
the small pointed end of the body. Larvae have  no

The life cycle of the fly includes:
•  egg-
•  larva,
•  pupa, and
•  adult.

•  Area behind the head  gray with stripes.  Abdo-
   men shiny blue.
•  Slightly larger than  housefly.
•  Common  during early  spring.
•  Life cycle is 2-3 weeks.
•  Attracted  to decaying  flesh.

•  Body shiny green or copper.
•  Slightly larger than housefly.
•  Garbage is common  breeding area.
•  Often  comes from  nearby  residential areas  or
•  Life cycle  is 9-18 days.
•  Common during summer months.

 • Adults dull gray with four stripes on area behind
   the  head.
 • About V*  inch long as adult.
 • Most abundant in fall, but may be found through-
   out  the year.
 • Larvae occur in animal waste  or  rotting fruits
   and vegetables.
 • Life cycle is  1-6 weeks.
   House Fly
•  Adults  about '/»  inch long and yellowish brown.
•  Attracted to sour or pungent  odors.
•  Adults  often found around overripe fruit or vege-
•  Life cycle is 8-11  days.
*  Eggs often laid on cracks in tomatoes and similar

Occasional Pests

•  Only adults  are  normally  seen.
•  Eat many foods but prefer sweets and grease.
•  Most species have  winged stage  once  a  year.
•  Most come in  from outside,  but  a few species
   nest in  walls.
The stages in the life cycle of an ant are:
* egg,
• larva,
• pupa, and
• adult.
 • Gray, silver,  or brownish  adults,  about Vi inch
 • Young resemble adults  but are smaller.
 • Silverfish like high humidity; firebrats prefer low
   humidity and  high temperature.
 • Can live a year or more without food.
 • Often found in warehouses, where they may dam-
   age paper and starch products.
                                                      Bristle Tail
The stages in the life cycle of silverfish and firebrats
•  the egg,
•  nymphs, and
•  adult,  which  continues to  molt throughout its
   life span.

•  Very small  (^n-Mo inch).
•  Young  resemble adults.
•  Normally live in moist areas and feed on fungi.
•  May be carried into food manufacturing plants
   on infested  pallets  and cardboard slipsheets.
•  Have been found in  newly manufactured empty
Life cycle takes a little over a month. The stages
• egg,
• nymph, and
• adult.

• Winged adults are attracted  to lights in summer-
• May  stray into food manufacturing plants  and
  contaminate food.
• May eat holes in paper, cloth, or rubber.
• Large hind legs adapted for jumping.

Stages in the  life cycle are:
• egg,
• nymphs, and
• adult.

 • Spiders are usually just a nuisance, but the black
   widow and brown  recluse  are  poisonous.
 • Spiders  are  more  commonly  found  in  ware-
   houses than in production areas.
 • Webs, bodies, and  excretions of spiders  can be
   a nuisance.
 • Presence of spiders  may indicate an insect infes-
   tation problem.
 • Mites are  extremely small.
 • Some mites contaminate food.
 • A  heavy infestation of mites produces  a  pro-
   nounced pungent odor.
 • Mites may cause skin rash to humans  and diges-
   tive disturbance if eaten.

 • Has many legs—one pair per segment.
 • Beneficial and eats insects, but may contaminate
 * Large populations are associated  with moisture
   and decaying  vegetable matter.
 • May enter from outside.
 * May frighten some workers, but not poisonous.

   Contaminate and destroy food products.
   Damage equipment,  structures,  and other  non-
   edible items.
   May carry diseases and ectoparasites.
   Can cause  fires.
   Have the ability to coexist with man.

The three most common kinds  are:
•  Norway, brown, or  common rat,
•  roof or black  rat, and
•  house mouse.

        Field Identification of Domestic Rodents
          ROW RAT Rottui ro«i»           TOUNC "*T
                    EAR    Er€  NOSE
                     !"Ul.   •  HLV.T
                                   FEET    HEAD
                                   HOUSf MOUSE
                                    Mm nvtcului
      NORWAY RAT  Ratlus nontgkvi
 The Norway rat prefers to live in underground bur-
 rows, but can climb readily. The roof rat prefers to
 live in  upper portions of a building, but may  use
 burrows. The house mouse lives in  any convenient
 protected space inside or outside.


 Only three  species  of birds—English  sparrows,
 pigeons, and starlings—are normally considered pests
 around  food  manufacturing  plants.  They are pri-
 marily objectionable because:
 • Their feathers  and droppings  can  contaminate
 • They may spread diseases.
 • They may ruin roofs and gutters  and deface build-
   ings with their droppings.
 • They sometimes carry mites which can bite man.




 Continual removal of  food  and water sources and
 destruction of  breeding places are essential in obtain-
 ing satisfactory cockroach control.  Apply  insecti-
 cides as crack and  crevice or  spot  treatments  to
 places  where  the  insects hide. Follow  label direc-
 tions for commercial food handling areas.

 Common hideouts are behind and beneath  built-in
 equipment,  beneath  trash,  in  floor drains,  sewers,
 and  in  cracks  and crevices in concrete,  brick, or
 block walls. Sprays  are usually preferred  to dusts
 because they are  easier to apply and the  residue is
 not visible. Dusts, however, can sometimes be blown
 into places difficult to reach with spray.

Use ULV (ultra low volume) concentrates  and aero-
sol applications of contact sprays and flushing agents
to supplement residual sprays  and  dusts. Use them
alone where the label prohibits  use of residuals.

Stored Product Pests

To eliminate infestations, find and destroy infested
materials and  treat the area where they are stored.
Some infested  materials can be treated with cold or
heat  or  fumigated. Thorough  cleaning  is essential
to remove spilled food to prevent  reinfestation.

Domestic Flies

Successful fly control must include a combination of
sanitation measures,  mechanical lures (electric grids),
physical barriers (screens or air curtains), and insec-
ticides. The  plant and  surrounding area should be
kept free of garbage, manure, and decaying plant or
animal matter. Continual removal of solid and liquid
process wastes  is essential to prevent the formation
of breeding sites. Control adults by spraying resting
places with the  use of aerosols or ULV concentrates.
Baits can be used to treat breeding sites.


Control ants by direct treatment of their nests. Dusts
can  be used on  outdoor-nesting ants.  For control
of indoor-nesting  ants, use  formulations that  will
not  move  far  from the  spray  site.  Follow  label
directions.  Sprays or granular insecticides can  also
be used on the nests and  surrounding area. If you
cannot locate the nest site, apply insecticides  where
the ants gain entry or hide—along foundation walls,
at doorways, windowsills, baseboards, or behind or
beneath equipment.


Directed sprays applied to cracks and crevices  that
serve as hiding and resting places are most frequently
used for  control; dusts  and baits may also be used
as well as aerosols and ULV concentrates.


Remove moisture and food sources. Directed sprays
and  aerosols are effective in  control.


Remove  trash piles  and tall  weeds.  If  a dump or
similar area is  a  breeding place, cover it with  6
inches of soil or ashes. Outdoor sprays give only
temporary control.   Inside, spray  residual pesticide
in areas  where crickets have been seen.


Control insects that serve as food, and remove webs.
Direct pesticide sprays  or dusts at hiding areas.


Remove sources of moisture  and decaying vegetable
matter. Use  wettable powders or emulsifiable con-
centrates of residual pesticide in a 2- to 3-foot strip
around the outside of  the building. Treat suspected
breeding sites by applying the pesticide with enough
water to carry it down to where the pests live.


A rat or mouse control program is based on know-
•  where they live, feed, and travel, and
•  the  extent of the infestation.

You must eliminate shelter, food,  and water. Close
all entrances the rats or mice use to come  and go
from buildings.  These preventive measures are the
key to successful control.  To  prevent rodent migra-
tion, it is  best to poison  or trap  before making
environmental changes.

The  two categories of rodenticides are:
•  multiple-dose anticoagulants, and
•  single-dose poisons.

Each rodenticide  has  special  characteristics, u$es,
and hazards. Some are highly  toxic  to  humans  and
pets. Mix, handle, and  apply them according to label

Place bait  deep into burrows or use  bait stations.
Keep them away from  people  and desirable animals.
Dispose of excess baits and dead animal  carcasses
at frequent intervals.

Mice will eagerly sample  new food.  Rats, however,
usually approach new food with caution. If it tastes
bad or makes them sick,  they will not  eat it again.
This is "bait shyness". When  using bait for control,
use a  bait that is fresh  and  identical  to  the food
the rats are using.  If you use  a different bait base,
prebait in  the area for a few nights  before using
a  toxic bait.  Alternate anticoagulants  with single-
dose poisons  to reduce possibility  of  the develop-
ment of resistance. Certain baits may attract insects
and should be replaced often.

Rats require water  to drink. Mice  may get water
from the food they eat. If all water sources can be
eliminated, liquid baits are  very  effective  for  rats
but only moderately so for mice.

Both rats and mice prefer to  run next to walls or
other surfaces. Place traps  and baits in these run-
ways.  Traps  may be used with bait, or the trigger

 device may be expanded and used without bait. Rats
 approach new objects cautiously.

 The mouse investigates any new object or change in
 its territory, so changing placement of baits or traps
 may improve control. Each house mouse establishes
 a territory which may not extend more than 10 feet
 from the nest. For this reason, baits and traps should
 be placed no more than  10 to 20  feet  apart.

 Be aware of nearby environmental disruptions that
 may cause rodents to enter buildings.


 Sanitation is the first step in control. Remove food,
 water,  and habitat. Control methods include build-
 ing out, removing food,  and using repellents,  traps,
 or avicides.

 Building out involves using new construction features
 or modifying existing features  so that birds cannot
 roost or nest.

 Repellents include various devices or substances in-
 stalled in potential bird  roosting and nesting  areas.
 They include revolving lights, noise makers (distress
 calls),  charged wires, and repellent glues or jellies.

 Traps are often used successfully in pigeon control.
 especially when prebaited for  a  few days. Release
 any birds that are protected by law from such control

 Population reduction includes shooting  (where per-
 missible) and the  use of  avicides. Chemical control
 is probably the most effective method. Follow label
 directions closely.  Know  your  city,  county,  State,
 and  Federal regulations.

Food plants have five areas of activity where pests
must  be controlled:
•  receiving and storage area for incoming materials,
•  processing area,
•  packaging area,
•  finished product warehouse and shipping area, and
•  grounds—the  building   exterior  and  the area
   around the plant.
Both  chemical  and nonchemical  controls are im-
portant in these areas. Nonchemical controls include
both  preventive  maintenance and mechanical and
physical measures.

Pests  may enter the plant in two ways:
•  by  slipping by the outside control programs, and
•  by  coming in with  ingredients  or materials.

Some nonchemical  control  methods  that apply  to
all areas inside a plant are:
•  Rodent-proofing and bird-proofing doors,  walls,
   windows,  and roofs.
•  Screening all windows that can be opened.
•  Eliminating cracks, crevices,  and  other  places
   where pests may hide.
•  Whenever  possible,  locating equipment  off the
   floor and  away from walls or sealing it to walls
   and floors.
•  Keeping the building clean and free  of litter.
•  Keeping the inside  and outside of all equipment
•  Using light traps for insects.


Xonchemical Controls

•  Visually inspect  all  vehicles, ingredients, and ma-
   terials to  insure that pests are not brought into
   storage  areas.
•  Store ingredients  and materials far enough away
  from walls to permit access for inspection.
•  Use FIFO (first in-first out) rotation  of incoming
•  Use traps or other  methods for rodents.
•  Use air curtains at  dock  and pedestrian doors  to
   keep insects out.
•  Use mechanical  repellents for birds.

Chemical Controls

•  Space treatment with nonresiduals.
•  Crack and crevice treatment  with  residuals.
•  Spot treatments with residuals.
•  Periodic general treatment.
•  Treatment of raw bulk commodities with  fumi-
  gants and sprays on receipt  and during storage
  where applicable.

• Bait stations.


Nonchemical Controls

• Place rodent traps near doors if situation warrants.

Chemical Controls

  Space treatment  with nonresiduals.
  Spot treatment with nonresiduals.
  Crack and crevice treatment  with  residuals.
  Contact treatment with nonresiduals.
  Periodic general  treatments.


Use the same pest  control methods in  the finished
products warehouse as in the materials receipt  and
storage area.

Vehicle inspection is essential to prevent the finished
products from  being placed in a pest-contaminated
carrier. Vehicle inspection is difficult,  particularly
for boxcars and trucks with false walls or endliners.
If vehicles are dirty or infested,  do not use them.

Chemical Controls in Vehicles

Before loading, consider:
• space treatment,  or
• crack and crevice treatment.

After  loading,  use:
• general treatment—usually  a  solid  fumigant—for
  in-transit control.


Nonchemical Control

• Eliminate all exposed dirt surfaces by paving all
  roadways or parking areas  and  maintaining well-
  kept lawns. This  will reduce  contamination from
  dirt, microbes, and other  airborne  particles.
•  Provide good drainage  to  help keep  the area
   clean and dry.
•  Place outside lighting away  from buildings and
   focus the lights toward buildings. This helps keep
   night-flying insects away from doors and windows.
•  Screen potential bird roosting areas.
•  Store equipment so that  it does not become a
   place for pests to hide.
•  Remove all  litter, weeds, and grass  clippings.
•  Eliminate  any waste  that may accumulate near
   exhaust systems.
•  Use rodent,  insect, and bird traps as necessary.

Chemical Control

•  Baits for rodents.
•  Baits, fogs, and sprays for insects.
•  Chemical repellents or avicides for birds.


• Excellent for flying or exposed insect pests.
• Disperse well if used correctly.
• Convenient and easy to store.
• Usually leave little surface deposit.
• Store well during normal  use period.
• Available for hand operations or can be installed
  as a timed  release system.

• No lasting protection.
• Good only  for exposed pests.
• Hazardous  if  container is punctured or over-
• Usually cannot be used during food processing or
  when people are present,


• Usually provide a deposit on surface.
• Can be  easily directed  onto surface for treatment.
• Easy to store, transport, and handle.
• Adaptable for use in many kinds of equipment.

• May be hazardous to use around electrical outlets
  (water or oil sprays).

   May  damage or  stain wallpaper,  varnish,  and    FUMIGANTS
   many fabrics (water or oil sprays).
   May  leave unsightly residue (wettable powders).
   Require agitation  during application  (wettable
   powders and emulsions).
   May  be  hazardous  around  open  flames  (oil
   May damage or etch asphalt, plastic tile, or rub-
   ber products (oil sprays).
   May make floors slippery  (oil sprays).
   May damage living plants (oil sprays).
                                                    Fumigants penetrate cracks, crevices, and the com-
                                                    modity being treated. They  must reach the target
                                                    pests as gases to be effective. As soon as a fumigant
                                                    diffuses from the target area, reinfestation can occur.
                                                    Fumigants must be applied in enclosed areas.

                                                    Types of Fumigation

                                                    Types of fumigation are:

• Excellent for crack and crevice treatments.
• May be  purchased ready-to-use.
• Usually  require  only  simple  and lightweight ap-
  plication equipment.
• Safe for  use around electrical equipment.
                                 surface  (should
                                 or above  food-
• Drift easily.
• Easily  dislodged  from treated
  not  be applied on equipment
  contact surfaces).
• Generally bulky to store.


• Ready-to-use.
• Do not drift.

• Can he used only on fairly level surfaces.
• May be tempting to nontarget animals.


• Can often control specific pests.
• Easily distributed.
• Easily monitored and recovered.
* Used in small amounts.

* Can be dangerous  to nontarget animals.
• Often  not as attractive as natural food supply.
• Rodents must feed for 5  to  15 days  on  an anti-
  coagulant rodenticide before  it is lethal.
* Rodents feeding on poison  baits may die any-
  where and go undetected, causing sanitation prob-
  general fumigation (buildings and their contents),
• spot fumigation (machinery, facilities, bulk com-
• tarpaulin or chamber fumigation  (packaged com-
  modities), and
• vehicle or in-transit fumigation (trucks, ships, and
  railway boxcars).

Selection of Fumigants
When choosing a  fumigant, consider:
• toxicity to the target pest,
• volatility and ability to penetrate,
• corrosive, flammability, and  explosive potential,
• warning properties and detection methods,
• effect  on seed  germination and  finished  product
• residue tolerances,
• availability,
• ease of application, and
• cost.

Several  factors  can change the efficiency of fumi-
gants. Consider these when selecting a formulation
and dosage:

Temperature—The fumigant may not kill the pests
if the product  or space  being  fumigated is below
10°C(50° F) or above 46° C( 115°  F).

Moisture—As the moisture content  of a commodity
increases, it becomes more difficult for a fumigant
to penetrate it. This  also increases  the potential for
residues exceeding legal tolerances.  Adequate mois-
ture  is required for  the  generation of some fumi-

Pests—Susceptibility  to fumigants depends  on spe-
cies, habitat, and stage of development. During some
stages of their life cycle, for example, many insects
are  protected by the  product  they infest.

Structure—Consider  the  condition  of the structure,
the type of construction, and the product it contains.

A wooden structure, even when sealed well, will not
retain fumigants as well as  metal, plastic,  masonry,
or concrete. Fumigation in vacuum chambers allows
increased efficiency.

Method of Application—Fumigants are widely used
because they can be applied in many ways. Fumiga-
tion techniques include:
•  Applying solid or liquid  formulations to streams
   of bulk grain.
•  Applying liquid  formulations  to the surface  of
   grain.  The  vapors flow down  through the grain
   either  by gravity or  by forced distribution  with
   bin aeration systems.
•  Piping  liquid or solid  formulations into a grain
   mass to eliminate local infestations.
•  Using spot fumigation in structures or in machin-
   ery or products.

Preparing  for Fumigation

Understand fully the facility and commodity  to  be
fumigated, including the:
•  design  of the structure, as well  as  adjacent and
   connecting  structures  both  above  and  below
•  persons or animals expected to be at or near the
   area to be fumigated,
•  the commodity, its history and condition (previous
   fumigation,  temperature, moisture),
•  availability  of emergency shutoff stations for elec-
   tricity,  water, and gas,
•  location of nearest telephone, and  numbers for
   fire or  police departments, hospitals,  and physi-

Select a  suitable  fumigant.

Understand label directions, warnings, and antidotes.

You may  need to notify local  medical,  fire, and
police  authorities  and  other security personnel
•  chemicals to be used,
•  proposed date  and time of use.
•  type of gas masks required,
•  fire hazard  rating, and
•  name  and phone number of person  to contact
   in event of  emergency.

Have alternate application and protective equipment
and  replacement  parts  available.  Display warning
signs near points of entry and provide for security
of buildings.  Have necessary first  aid  equipment
available.  Before treatment is started, develop plans
to ventilate the area when  the  treatment period is


Always  assign  two  persons  to  each fumigation.
Everyone involved  in the fumigation  should  know
first  aid  and  other emergency procedures, including
personal  decontamination.

Follow  label  directions  exactly when applying a
fumigant. Consider prevailing winds and other per-
tinent  weather  factors such  as  temperature and
humidity. Apply fumigants from outside the exposed
areas wherever possible.

Inspect all valves, gauges,  and  in-plant piping be-
fore  using built-in  fumigation  system  where  fumi-
gant source may be either inside or outside the area
being treated.

Return to the storage area all unused  chemicals  in
clearly  labeled,  original containers.   Dispose   of
empty containers correctly.

Provide watchmen, when required. Entrances should
be secured by guards or locks.

Report to company-retained physician  or to  desig-
nated personnel,  indications of illness or physical
discomfort, no  matter how  minor they seem. These
symptoms and  signs may include: dizziness, nausea,
headaches, and lack of coordination.

Do not  consume alcohol for 24 hours before  or
after  a fumigation.

After Application

Before reentry, use a suitable  gas detector, as indi-
acted on the label, to determine fumigant concentra-
tion. Do not depend on odors. Some fumigant gases
are odorless.  Wear correct respiratory equipment.

Turn on  all ventilating or aerating fans.

Check for gas  concentrations  in areas that are ex-
pected to aerate slowly.

Remove  warning signs when the gas concentration
is within safe limits for human exposure.

Remove and dispose of packaging and waste prod-
ucts of solid fumigants.

Fumigants are useful but  have specific  advantages
and limitations.

•  Toxic to many pests.
0  Can be applied by various methods,
•  Easy to apply without disturbing the commodity.
•  Penetrate structures, commodities, and equipment.
•  Readily available  and economical.

•  Toxic to  humans.
•  Require trained applicators.
•  Target  area or commodity must be enclosed.
•  May  injure seed  germination.
•  Temperature requirements may be  hard to meet,
   especially in northern climates.

Vapors are volatilized by  supplementary heat or by
inherent high vapor pressure to produce a gas. They
are usually dispersed from impregnated resin strips,
or vaporizers.

•  Easy to apply  and safe to handle.
•  Can be used where fumigant tolerances may be
•  Sealed building not as essential as for fumigants.
•  Effective  against  flying insects  such as  moths
   and flies.

•  Will not penetrate commodities in concentrations
   lethal to target pests.
•  Resin strips cannot be  used in plant  areas where
   food is exposed.
                                                                    * US. GOVERNMENT PRINTING OFFICE 1S76- 210-810/162