Pesticide Guidelines Part IV

Guidelines for the use of pesticides
Chapter 6 PESTICIDE HAZARDS AND FIRST AID
Summary
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Know how to identify and differentiate between types of harmful effects associated with
pesticide application.
Understand the hazard level classification system for pesticides, including the associated signal words
Know how to identify the common exposure routes for various pesticides and application
methods.
Know how to recognize typical symptoms of pesticide exposure in humans and be
aware of the appropriate first aid response.
To be effective in controlling the pest, pesticides must be toxic or poisonous to kill the pest
they intended to control. But because pesticides are toxic, they are potentially hazardous to
humans and animals as well as to pests as their target site of action in the pest could be similar to that in humans and animals. Since pesticide toxicity varies, it is important for an pesticide operator to have at least a general knowledge of the relative toxicity of the products they
are using.
TOXICITY, EXPOSURE AND HAZARD
Product Toxicity refers to the ability of a pesticide to cause damage after a short-term (acute
toxicity) or long-term (chronic toxicity) exposure.
1.
Lethal Dose 50% or LD50 is the dose of a toxicant required to kill 50% of the population
of the test animals under a standard set of conditions. It is recorded in milligrams of toxicant per kilogram of body weight of the test animal (mg/kg). Oral LD50 refers to the test
animal being exposed to the toxicant by feeding. Dermal LD50 refers to the test animal
being exposed to the toxicant by skin exposure.
2.
Lethal Concentration 50% or LC50 is the concentration of toxicant in air or water required to kill 50% of the test population. This is commonly expressed in parts per million
(ppm) or milligrams per liter (mg/l). It is a common measurement of the lethal effect of
the toxicant on fishes and other aquatic organisms.
Category (US Environmental Protection Agency)
Signal Word
Required on Label
Oral LD50
mg/kg
Dermal LD50
mg/kg
Inhalation
LC50 mg/lit
I. Highly Toxic
DANGER
POISON
From 0 to 50
From 0 to 200
II. Moderately
Toxic
WARNING
From 50 to 500
From 200 to 2,000 From 0.2 to 2
III. Slightly Toxic
CAUTION
From 500 to 5,000 From 2,000 to
20,000
From 2.0 to 20
IV. Slightly Toxic
CAUTION
(Optional)
More than 5,000
Greater than 20 Over 1 pint (0.568
lit.) or 1 pound
(0.453kg).
More than 20,000
From 0 to 0.2
Approximate Oral
Dose to kill an
average person.
A few drops to 1 tsp
Over 1 tsp to 1
ounce (~28g)
Over 1 ounce to 1
pint (0.568 lit.) or 1
pound (0.453kg)
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Guidelines for the use of pesticides
Exposure occurs when pesticides get onto or into the body through the skin, by inhalation,
by swallowing, or by eye contact. Exposure occurs mainly when handling opened containers,
mixing and loading, working around contaminated application equipment, carrying out spray,
mist or dust applications, cleaning up spills or re-entering a recently treated area before the
spray has dried or the dusts have settled.
Hazard or risk is the main concern for the pesticide applicator or handler. It is the potential or
probability for harm (injury, illness or allergy) to occur because of product toxicity and human
exposure. The words “toxicity” and “hazard” are not the same. “Hazard” reflects both the
pesticide’s toxicity and the likelihood that you will be exposed to the product in a particular
situation. “Toxicity” is a measure of the pesticide’s capacity to cause injury which is a combination of its chemical properties and its concentration.
Hazard (Risk) = Toxicity x Exposure
EFFECTS OF PESTICIDE
Pesticide injuries occur because the products can cause damage by contact with skin, eyes
or respiratory tract; can be absorbed by the body and cause systemic effects; and can induce allergic responses. Any chemical can be harmful; some even deadly. Many chemicals
we are exposed to daily have risks associated with their use because of their toxicity and
over exposure. Pesticide is just like any other chemical, the risk of illness or injury is determined by both the dose (level of exposure) and the toxicity.
Contact Effects
Contact symptoms include skin irritation such as itching, redness, rashes, blisters and burns.
Skin discolouration may also occur.
Systemic Effects
Systemic effects in humans occur primarily when people are exposed to pesticides. For example, the nervous system of insects is very similar to that of humans. Thus, an insecticide
targeting an insect nervous system often affects a human if the dose is sufficient. Likewise,
the blood system in rodents is similar to the human circulatory system. Therefore, rodenticides that target the blood system of rodents may also affect a human. Fumigants are another class of pesticides that can cause systemic injury.
Allergic Effects
Allergic effects are harmful effects some people develop in reaction to substances that may
not cause the same reaction in most other people.
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Guidelines for the use of pesticides
Pesticide Exposure—How it enters our body?
Dermal Exposure
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•
•
•
•
•
•
Not wearing gloves or other protective clothing.
Not washing hands after handling pesticides, product
containers or application equipment.
Not washing hands before using the toilet.
Splashing or spilling of pesticide on the skin.
Being exposed to spray or dust drift.
Applying pesticides in windy weather or above your head.
Touching treated plants, soil or livestock.
Eye Exposure
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•
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Rubbing eyes with contaminated gloves or hands.
Splashing pesticides into the eyes.
Handling dry formulations when not wearing eye protection.
Oral Exposure
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Not washing hands before eating, smoking, chewing or
drinking.
•
Splashing pesticide into the mouth.
Inhalation Exposure
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Handling pesticides in a confined or poorly ventilated
areas.
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Handling dusts or powders.
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Using an inadequate or poorly fitted respirator.
•
Being exposed to spray or dust drift.
Pesticide Poisoning Symptoms
Mild Poisoning
Moderate Poisoning
Severe Poisoning
Fatigue
Dizziness
Blurred vision
Headache
Excessive sweating/salivation
Nausea & vomiting
Stomach cramps & diarrhea
Inability to walk
Weakness
Chest discomfort
Constriction of pupils
Unconsciousness
Severe constriction of pupils
Muscle twitching
Running nose & drooling
Breathing difficulty
Coma & death
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Guidelines for the use of pesticides
FIRST AID FOR PESTICIDE POISONING
Pesticide on the skin
Remove all contaminated clothing immediately.
Wash the affected area, including the hair, with water and
soap, then rinse well. Use of a shower is the best. Avoid
harsh scrubbing, which will enhances pesticide absorption.
Gently dry the affected area and wrap it in loose cloth or a
blanket, if necessary.
If the skin has chemical burns, cover the area loosely with a clean, soft cloth. Avoid using ointments, greases, powders and other medications unless instructed to do so by a medical personnel.
Pesticide in the eyes
Immediately hold the eyelid open and gently wash the affected eyes with drips of clean water.
Do not use chemicals or drugs in the wash water unless instructed to do so by a physician or a
poison control center. Drip the water across the eye, not directly into the eye or use an eyewash dispenser.
Continuously rinse the eyes for 15 minutes. If only one eye is involved, be careful not to contaminate the other eye.
Flush water under the eyelids to remove debris. Cover the eye with a clean piece of cloth and
seek medical attention immediately.
Inhaled Pesticide
Immediately carry the victim to fresh air—do not allow the victim to walk.
Do not attempt to rescue someone who is in an enclosed, contaminated area unless you are
wearing appropriate PPE.
If other people are in the vicinity, warn them of the danger.
Have the victim lie down and loosen the clothing.
Keep the victim warm and quiet. Do not allow him/her to become chilled or overheated.
If the victim is convulsing, protect the victim’s head and watch that breathing continues.
Keep the person’s chin up to ensure that air passages are open for breathing.
If breathing stops or is irregular, give artificial respiration.
Pesticide in the mouth or swallowed.
If the pesticide has got into the mouth but has not been swallowed, rinse the mouth with plenty
of water. After this, give the victim large amount (up to 1 litre) of milk or water to drink.
If the pesticide is swallowed, one of the most critical first aid
decision is whether to induce vomiting. Induce vomiting only if
the label instructs to do so. Several pesticides cause more
harm when vomited than if they remain in the stomach.
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Guidelines for the use of pesticides
Chapter 7 PERSONAL PROTECTIVE EQUIPMENT (PPE)
Summary
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Understand the importance of personal protective equipment worn during pesticide application.
PURPOSE OF PERSONAL PROTECTIVE EQUIPMENT (PPE)
Pesticides can enter the body through the eyes, the mouth, the skin and through inhalation
into the lungs. It is best to avoid direct contact with pesticide by wearing the proper protective
clothing. Pesticide operators generally get pesticide poisoning through skin contact. Most pesticide is absorbed into the skin within the first few minutes of contact. Hence, PPE should be
worn for personal safety during mixing and filling of pesticides when the contamination risks
are the highest ie. when pesticide concentrates are being handled during measuring out for
mixing and filling. And for personal safety during spraying as the risk of operator contamination can arise from sprayer leakage, drift from the nozzle, operator contact with sprayed crops
and dripping of liquid sprays from tall plants or trees. PPE may be uncomfortable in the
tropics but they are necessary for operator safety.
What are Personal Protective Equipment that you should use?
Gloves
Always wear unlined, elbow length chemical resistant gloves when handling any pesticides
except those that are category IV or of lower toxicity. The elbow length gloves protect your
wrists and prevent pesticides from running down your sleeves into your gloves.
Body Covering
Regular work attire of long pants and a long-sleeved shirt, shoes and socks are acceptable
for slightly toxic (category III) and relatively non-toxic (Category IV) pesticides. Pesticide operator should reserve one set of clothing for pesticide use only.
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Guidelines for the use of pesticides
For application of Category II (Moderately Toxic) or I (Highly Toxic) pesticides, always wear
a clean & dry protective suit that covers your entire body from wrists to ankles. The sleeves
must be long enough to overlap with the gloves. Openings, such as pockets, should be kept
to a minimum. Protective suits are one or two-piece garments such as coveralls. Cotton coveralls are good choice for general use because they are comfortable, lightweight, reusable
and less costly. They are better suited for exposure to pesticides in dust, granule or powder
form. But these are not recommended for use with liquid pesticides.
Apron
Wear a chemical-resistant apron when repairing o cleaning spray equipment and when mixing or loading. The apron is an essential PPE for operator handling pesticides of Category I
and II. Choose an apron that extends from the neck to at least the knee level.
Boots
Wear unlined chemical resistant boots which covers your ankles when handling or applying
moderately or highly toxic pesticides (Category II & I). Nitrile and butyl boots appear to give
the best protection. Do not use leather boots. The pant legs should be placed outside the
boots to avoid any pesticide draining into the boot. Wash the boots after each use and dry
thoroughly inside and out to remove any pesticide residue. Boots used for pesticide application should not be used for other purpose ie have a dedicated boots for pesticide use only.
Goggles or Face Shield
Wear shielded safety glasses, a full-face respirator or a full-face shield when you will be
coming into contact with pesticide to protect your eyes. Safety glasses with brow and side
shields are acceptable for low exposure situations. Always wear goggles or full face respirator when you are pouring or mixing concentrates or working with a highly toxic spray or dust.
Clean them after each use. Be careful of the headband as it is often made of material which
readily absorbs and holds chemicals.
Respirators (Or N91 type mask)
Respirators protect the pesticide operator from inhaling any toxic chemical. The pesticide label will indicate if a respirator is required. The respirator should be worn during any lengthy
exposure with a high risk pesticide inhalation. Always wear a respirator while mixing or filling
highly toxic pesticides. Pesticide operator who will be constantly exposed to small amounts
of moderately toxic pesticides for a day or several days should also wear a respirator.
The respirator should fit properly on your face. It should be worn tightly enough to form a
seal around your face. Before using a respirator for pesticide application, the pesticide operator should test the respirator. The headband should be properly adjusted to fit nicely to
avoid headaches or dizziness of the operator. After each use, wash the face piece with detergent and warm water. Rinse thoroughly and wipe dry with a clean cloth. Store the respirator, filters and cartridges in a clean and dry place away from any pesticide. A tightly closed
plastic bag works well for storage of respirator.
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Guidelines for the use of pesticides
Chapter 8 TRANSPORTATION AND STORAGE OF PESTICIDES
Summary
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•
Understand the importance of handling, storing and disposing pesticides properly.
Know what to do when handling a pesticide spill.
TRANSPORT
In Singapore, the transportation of hazardous substances like pesticides is subjected to laws
and regulations governed by the National Environment Agency (NEA). Their purpose is to
make such operation as safe as possible and to deal effectively with accidents where they occur. If you need to transport pesticides from one location to another, please check and comply
with existing laws.
•
Keep pesticides away from passengers, livestock/animals and foodstuffs during
transportation.
•
Load and unload pesticide packages with care. Never place them under other heavy
items which may crush them nor allow them to drop from a height. Secure containers so
that they will not roll or slide during transport.
STORAGE
Pesticides are products that may deteriorate and become hazardous if they are not stored under proper conditions. Consult the label for advice on storage.
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Always handle pesticides & their containers in PPE.
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Always keep pesticides in their original containers with labels intact.
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Always maintain proper record of the list of pesticides stored and a usage record.
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Keep them out of reach of children, preferably locked in a separate cupboard or box and
never where they might be mistaken for food or drink.
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Keep them dry, away from fire and out of direct sunlight.
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Store pesticides separately, preferably in a separate building under lock and key.
•
Store pesticides in an area that is not prone to flooding, located downwind and downhill
from sensitive areas such as houses, ponds, play areas or water catchment.
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Guidelines for the use of pesticides
The Storage Area
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Cool, dry and airy room or building that is fireproof.
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A properly installed ventilation system with a switch outside
so that the fans can be turned on before anyone enters the
facility/area.
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Should be fenced in or lockable to prevent unauthorized access.
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Weatherproof warning signs should alert persons to stay away.
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Proper installed drainage system for collection of possible runoff water from the area
that should be treated as surplus pesticide and be disposed properly.
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Available supply of detergent or soap, hand cleanser and water .
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Absorbable clay, activated charcoal, vermiculite, pet litter or sawdust should be readily
available at the storage site to soak up any spills or leaks. Hydrated lime and high pH
commercial detergent should also be available to neutralize the pesticide in case of any
emergency. A shovel, broom, dust pan and a fire extinguisher should be available.
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Do not store pesticides with food, animal feeds, drinks or PPE.
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For maintenance of pesticide records, you may refer to example form attached.
Handling Pesticide Containers
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They should be stored off the floor to avoid damage by dampness.
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Rigid containers should always be stored in an upright position. They should be stored
in orderly rows with enough room to allow for access.
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They should be checked often for corrosion, leaks or loose caps.
Pesticide Equipment Storage
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All pesticide application equipment should be stored in a special area, away from
children and food. Only store properly cleansed equipment after use.
Notify the authorities ie AVA,
DEALING WITH SPILLAGE
NEA, Police, SCDF accordingly
If spillage or leaks do occur:
of any large chemical spill
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Wear PPE during clean-up operations.
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Keep people and animals away.
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If pesticide spills on a person, wash it off immediately. Have them get out of the area,
remove and wash affected clothing, thoroughly wash contaminated skin areas with
soap and water. Change clothes and see a doctor if in doubt or where necessary.
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If the spill is a liquid, throw activated charcoal, absorptive clay, vermiculite, pet litter or
sawdust over the entire spill. Use enough to soak up most of the liquid. Then sweep or
shovel it into a large drum.
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If the spill is dust, granular or powder, sweep or shovel it directly into a large drum.
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Contaminated material ie rinsed water, activated charcoal etc should be properly disposed off.
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Check the label or supplier/manufacturer for further instructions on spillage.
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If a decontamination agent is recommended and available, cover the spill area with it.
Hydrated lime and high pH commercial detergents are often recommended. Follow instructions on decontamination procedures as recommended.
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Purchase
Reference
Date of
Delivery
Brand & Supplier Active ingredi- Expiry
ent
Date
Example of Maintenance of Pesticide Record Form
Date
Opened
Officer's Verified
initial
by
Date
Used Up
Officer 's Verified
initial
by
Date
Discarded
Officer Verified
by
Comments
Guidelines for the use of pesticides
Chapter 9 MIXING AND APPLICATION OF PESTICIDES
Summary
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Know the precautions to take during mixing and spraying of pesticides.
Know how to select a suitable nozzle and how to mix pesticides for use.
Learn about the calibration procedures for pesticide use.
PRECAUTIONS TO TAKE
Pesticide use is dependent upon the crop, the pest problem and the equipment to be used.
Always read and follow the label instructions on dose, technique, protective clothing, timing,
repeat applications etc. Before you start mixing the pesticide, you should be aware of the following:
Additives/Adjuvants
An adjuvant is a chemical added to the pesticide mixture that helps the active ingredient (AI)
to do a better job. Spreaders and stickers help the AI spread evenly over the treated surface
and stay there in spite of rain, wind or bad weather. These may already been included in the
formulations.
Compatibility
Often two or more pesticides are mixed together in a sprayer tank in order to control more
than one pest with the same application. However to do so, the pesticides must be compatible, ie. They must be able to be mixed together without reducing their effectiveness in any
way. Some pesticides may be incompatible and hence, always check the labels or consult the
manufacturer before mixing.
pH of water
Alkaline (pH of 8.0 or more) spray water may lead to chemical breakdown of the AI. If the water is alkaline and you are using a pesticide that is sensitive to high pH, you should lower the
pH of the water in the spray tank. A pH in the range of 4 to 6 is recommended for most pesticide sprays. You can adjust the spray solution to the 4—6 pH range by using adjuvants that
are marketed for this purpose.
PESTICIDE APPLICATION EQUIPMENT
The most commonly used equipment will be hand-operated sprayers. The use of such applicators brings the operators into close proximity to the spray and it is therefore essential that
particular care is taken with the choice and use of the equipment and protective clothing. Most
application equipment can be placed into 2 groups : 1. For dry pesticide formulation and 2.
For liquid pesticide formulation.
1. Dry Formulation Equipment
2. Liquid Formulation Equipment
Example : Dusters
Examples:
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•
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Hand Operated Sprayers
(Hydraulic & Rotary atomizer)
Low, Ultra Low Volume Sprayers
Aerosol Generator
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Guidelines for the use of pesticides
Sprayer Nozzle
All spraying equipment uses either hydraulic nozzles or rotary atomizers to transform the
spray mixture into droplets. Spray quality varies with the range of droplet sizes produced. It
is essential that the nozzle chosen for a particular pesticide application should give the
spray quality indicated on the product label. Nozzles regulates the flow of liquid, atomize
the liquid stream into droplets and spread droplets in a specific pattern.
Regulate Flow
A nozzle regulates the flow of liquid with the size of its orifice. With most nozzles, flow rate
increases as pressure increases. However, pressure must be increased four times to double the flow rate or use the optimal pressure.
Atomize Stream
Each nozzle produces a range of droplet sizes from very fine to large. Droplet size is measured in microns (One micron = one thousandth of a millimeter).
Table 2 : Characteristics of Spray Qualities*
* *Adopted from the British Crop Protection Council.
Spray Quality
Very Fine
Size of Droplets
Main uses
Good
Exceptional
Circumstances
Fine
Good
Good Cover
Medium
Good
Most products & uses
Coarse
Moderate
Very Coarse
Finer
Retention on
Difficult leaf
surface
Coarser
Poor
Potential Drift
Hazard
High
Soil herbicides
Liquid Fertilizers
Very Low
Table 3 : Type of Nozzle Materials
Brass
The most commonly used, least resistant to wear and relatively
inexpensive.
Nylon
For non-abrasive formulations. Inexpensive and corrosion resistant. Not recommended for high pressure.
Plastic (Polymer)
Can be used for corrosive chemicals. Different grades of plastic
available.
Stainless Steel
Non-corrosive, excellent wear resistance and relatively expensive.
Hardened Stainless Steel
Very durable and useful for highly abrasive formulations.
Ceramic
Most durable tip for highly abrasive and/or corrosive chemicals.
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Guidelines for the use of pesticides
Type of Nozzle and its Spray Patterns
1.
Hollow cone and solid cone Nozzle
These nozzles produce a circular pattern. Hollow cone nozzles generally make finer, smaller particles than the solid
cone. They generally penetrate foliage well and are used to
apply fungicides, insecticides and sometimes herbicides.
2.
Flat Spray Nozzle
These are used to broadcast most types
of pesticides. The pattern created is a fan
shaped with gradually tapered edges. Uniform coverage across the sprayer width is
achieved by overlapping the tapered portion of the pattern. This is also a common
spray pattern used for applying structural
herbicides to floor or wall surfaces.
3.
Even Spray Nozzle
These produce a narrow rectangular pattern with a sharp cut of edges.
They are used for band applications of chemicals and are frequently used
with planting equipment.
4.
Flooding Nozzle
These are used for broadcast application of
fertilizers, herbicides and defoliants. They
deliver a wide flat spray pattern consisting
of large droplets. They can be mounted on
a boom in a variety of positions and are
sometimes used alone for boomless
broadcast spraying.
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Guidelines for the use of pesticides
Cleaning Sprayers
The sprayer should be thoroughly cleaned after each use using the proper PPE. The following steps are recommended:
1.
Flush the inside of the tank with clean water and partially fill it with water.
2.
Flush this water through the nozzles. When the tank is empty, repeat these steps so
that two complete rinses of the tank are carried out.
3.
Remove the nozzle tip and screens. Clean them in a strong detergent solution or
kerosene with a soft brush.
4.
Fill the tank the third time with a cleaning agent ie detergent.
5.
Finally rinse the outside of the tank and straps. Check for any defects and then store
in a cool, dark, dry, secure and well ventilated space.
6.
All rinsed water should be properly disposed off.
MIXING THE PESTICIDE FOR APPLICATION
Mixing sites must be well away from watercourses or other environmentally sensitive areas. It is
essential to avoid skin contamination by wearing appropriate PPE as recommended on
the product label.
•
Always read and check the pesticide label.
•
Always adhere to the recommended dose rates and dilutions on the label. Higher
doses will not produce better results. Lower doses will be less effective. The method
adopted for measuring and preparation for use will vary according to the product
and the scale of use.
•
Ready-to-use (RTU) products can be added directly into the sprayer container.
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Concentrates which mix easily with water can be measured out and then poured directly into sprayer tank partly filled with water.
•
Half fill the sprayer tank with clean water. Add the measured product. (Adding
the product first might fill the pump with concentrate). Rinse the measuring
vessel and the product container, if it has been emptied, and pour the rinsing
into the tank.
•
Fit the tank lid and gently shake the sprayer, by rocking or use a stirrer to ensure thorough mixing.
•
Remove the lid and top up the tank with water to the correct level. Ensure that
the tank is not overfilled and is clean and dry before handling.
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Empty containers must be safely disposed of, in compliance with regulations.
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Check if wettable powders need creaming before being added to the tank. Wettable
powders may best pre-mixed (‘creamed’) with a little water before pouring into the
sprayer tank. Only shake a product container if the
label say so. Measure out the calculated quantity
with care, using a clean measure dedicated to this
purpose. Handle wettable powder carefully to avoid
a dust cloud.
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Guidelines for the use of pesticides
CALCULATION FOR MIXING PESTICIDE TO RECOMMENDED DOSAGE
Refer to the Product Label for the recommended dosage to use ie usually in the form of “ml/
Litres” or “g/Litres” or “per cent concentration of active ingredient”.
A.
1.
Based on Quantity of Pesticide ie Volume or weight
To determine the volume (Vi) of a pesticide of given concentration MI required to be
added to a spray tank with capacity, VF to prepare the recommended dosage MF :
Formula Dosage x Tank Capacity/Req. Volume = Quantity of Pesticide Required
Example:
Recommended Dosage MF is 5ml/L or 5ml of product in 1 litre working solution.
If the Tank Capacity is VF = 200 litres, volume of Product to be added into tank is
5ml/L (DOSAGE) X 200 Litres (TANK CAPACITY) = 1000ml or 1 Litre product
2.
The Recommended Dosage of a fungicide is 5 gm of the formulation to 1 litre of water.
If 500 litres of fungicide is required to spray an area of 1 ha, what is the amount of fungicide you should use to prepare the volume to spray an area of 15,000m2 ?
1 ha = 10,000m2
15,000m2 = 15,000 / 10,000 = 1.5 ha
For 1 ha, you need 500 litres of fungicide. For 1.5ha, 500 x 1.5 = 750 litres (VF) of
fungicide will be required. To prepare a 750 litres of spray solution at a recommended
dosage of 5g/L (MF), 5 g/L (DOSAGE) x 750 litres (REQUIRED VOLUME) = 3,750g/
3.75kg of fungicide needs to be added into 750 litres.
B.
3.
Based on % of Active Ingredient
To determine the quantity (Vi) of active ingredient at given % concentration of AI (MI)
required to be added to a spray tank with capacity (VF) to prepare the recommended
dosage (MF).
Formula
MI x Vi = MF x VF ; Vi = MF x VF
MI
Example:
Recommended Dosage (MF ) = 0.5% AI; Spray Tank Capacity (VF) required = 100litres;
Concentration of Pesticide (Wettable Powder) = 50% (MI) . Therefore, to prepare 100
litres of 0.5% AI working spray solution, = [(0.5% (MF ) x 100 litres (VF)) / 50% (MI)]
= 1kg of 50% Pesticide (Vi) needs to be added into the tank
Example:
Recommended Spray Dosage (MF ) = 0.025% AI; Spray volume (VF) required = 500 L
Concentration of Cypermethrin (EC) = 20% (MI). Therefore, to prepare 500 litres of
0.025% Cypermethrin working spray solution, = [(0.025% (MF ) x 500 litres (VF)) / 20%
(MI)] = 0.625 litres or 625 ml of 20% EC Cypermethrin (Vi) needs 20% (MI) to be
added into the tank.
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