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Six steps to safe insecticide use

Insecticides are some of the most toxic chemicals used on Prairie farms. Remind yourself or someone you love about these 6 steps to insecticide safety

Some farmers may never spray an insecticide. Others may spray for grasshoppers or flea beetles in an emerging crop, but later season pests such as bertha armyworm, diamondback moth or aphids are often aerially sprayed. “There is not a lot of focus on insecticides generally because they are not used every year as herbicides are,” says Harry Brook, a crop specialist with Alberta Agriculture and Rural Development.

Toxicity

Insecticides tend to have higher levels of toxicity than herbicides and fungicides and, as a result, can have implications for human health and the environment. It’s important to follow safety precautions, understand the chemicals that you are working with and use them judiciously. “Unlike herbicides, insecticides can have significant human health issues and proper hygiene is even more important for that reason,” says Tom Wolf, a research scientist at Agriculture and Agri-Food Canada’s Saskatoon Research Centre.

Insecticides use different mechanisms to kill insects at different stages of their development. Ovicides, for example, kill insect eggs; larvicides kill larvae. Unfortunately insecticides do not discriminate as to which species they kill, so it’s important not to allow insecticides to be sprayed, spilled or to drift into non-target areas, to avoid killing beneficial organisms.

Insecticides can be particularly toxic to fish and other aquatic organisms, as well as birds. For example, the common insecticide Lorsban (clorpyrifos), as well as other products such as synthetic pyrethroids, can be toxic to aquatic life at very low concentrations.

“The Pest Management Regulatory Agency considers Lorban safe at 100 parts per trillion, that means about 0.4 millilitres of the active ingredient in an Olympic swimming pool, which is not very much,” says Wolf.

These products are handled several times — transported to the farm, moved to an on-farm storage site, mixed and loaded. In addition, empty containers and sprayers need to be cleaned out before disposal. All of these activities pose a risk to human safety and the environment because handlers are directly exposed to the concentrated product. When improperly used or spilled, some insecticides can cause serious and immediate, acute human health problems or longer-term, chronic conditions. Large quantities of insecticides which find their way into a water supply due to a spill can cause skin rashes, nausea, eye irritations or other toxic effects.

As insecticides tend to be more potent than herbicides, they need at least the same careful consideration when it comes to handling, application, clean-up, storage and disposal.

Alberta Agriculture offers a Farmer Pesticide Training Certificate Course which can be taken by correspondence and is required if farmers want to use restricted pesticides in Alberta. It has a handy interactive component with useful learning activities, which can be accessed online.

Follow these steps to keep yourself, your family and the environment safe during this growing season.

1. Know what’s in it

It’s important to be aware of the physical and chemical properties of the insecticide you’re working with. These include: toxicity, degradation, volatility, solubility, adsorption, absorption and bio-accumulation. These properties influence the insecticide’s potential to harm humans, animals and the environment. They should be indicated on the product label or on the product’s Material Data Safety Sheet, which will often accompany the purchased product or can be downloaded from the manufacturer’s website.

2  Know where you’re using it

Knowing your land is an important first step in applying any chemical control effectively and safely. Soil texture, depth and permeability play an important role in application and storage considerations. Fine textured (clay) soils, for example, have a higher potential for runoff but a lower risk of leaching. Coarse textured (sandy) soils have less risk for runoff but there is more potential for groundwater contamination. Slope of the land also can affect the risk of contamination from runoff, especially if close to a watercourse. Make sure to take this into account when choosing a storage site.

3. Handle and apply with caution

Handle any pesticide carefully and wear the appropriate personal protective clothing and equipment. Labels on chemical containers have symbols indicating what risk the contents pose to the user. Where there is minimal risk, no symbol is required, but protective clothing should still be worn. Different protective clothing is required depending on the toxicity level of the pesticide being used.

There are many different formulations of insecticides such as powders, granules and liquids, some should not be tank mixed with other products. For example emulsifiable concentrate (EC) insecticides should not be mixed with fungicides or herbicides. Always check product labels for any possible interactions.

Never smoke or eat while applying pesticides and avoid inhaling spray or dust. Wear a respirator if necessary. Have soap, water and a towel available wherever you are handling insecticides so that if you do spill the product on your skin, or if it splashes into your eyes, you can wash them immediately. Always wash your hands and face when you are finished handling or applying insecticides and before break periods, lunch or going to the bathroom. Bathe or shower immediately after working with pesticides and change to clean clothing. Thoroughly wash soiled clothing before re-using.

If any symptoms of illness occur during or shortly after pesticide handling or application, call a doctor or get the exposed person to a hospital immediately. Pesticide poisoning can have mild to severe symptoms ranging from headaches, nausea and skin irritation to breathing difficulties or fever. If in any doubt get a medical opinion. Make sure that take the label or container of the product to the doctor with you.

4. Avoid spray drift

Avoid spray drift by paying careful attention to environmental conditions such as wind speed and direction, temperature and relative humidity. Generally it is not recommended to spray at wind speeds above 25 kilometres per hour. Avoid night spraying under conditions of temperature inversion, when air near the ground is cooler than the air above it causing poor spray dispersal. Temperature and relative humidity (RH) affect how quickly spray droplets evaporate. Droplets will evaporate more quickly at higher temperatures and lower RH, making them more prone to drift.

Use the appropriate spray quality, carrier volumes, pressure and low drift nozzle types for the product and situation. Coarser sprays are less likely to drift than finer sprays. Reduce speed and use a lower boom height to further reduce drift and be aware of the impact spraying will have, particularly on other crops or sensitive areas downwind.

5. Wear protective clothing

Always remember to discard clothing which has been worn when using insecticides before entering the house. Any items which have been badly soiled by highly toxic, undiluted chemicals should be discarded.

Goggles should be chemical-resistant to protect from splashing and dust or granules. Don’t use goggles with cloth or elastic headbands, which absorb pesticides. Goggles should fit snugly to also protect the side of your head. If you wear glasses, purchase goggles which fit snugly over them and never wear contact lenses when working around pesticides.

Coveralls: If you use disposable coveralls when mixing and applying pesticides they should be discarded at the end of the day, or at once if they become contaminated. Reusable fabric coveralls should be washed thoroughly each day before re-using. Separate pesticide-soiled clothes from other family laundry and wash as soon as possible after wearing using hot water and a long wash cycle. Use the type of detergent recommended on the chemical label. Generally a heavy-duty liquid detergent is best for laundering liquid type insecticides and a powder detergent for powder or granular forms. De-contaminate the washing machine afterwards by running a complete wash cycle with hot water and detergent but no clothing. It is best to air dry garments if possible rather than using the dryer. Fabric coveralls should not be used for highly toxic and concentrated pesticides. Close coveralls right up to the neck and wear over long-sleeved shirts and pants. Do not wear shorts under coveralls.

Gloves: Wear chemical-resistant gloves which are designed for use with solvents and pesticides. Never use lined gloves, gloves with fabric wristbands or leather gloves.

Headwear: Use a chemical-resistant hat or hard hat, preferably made of washable plastic and with a plastic, not fabric sweatband. The hat should be washed thoroughly after each use. Never wear baseball caps with cloth sweatbands because they will absorb the pesticide and re-contaminate if worn again.

Footwear: Wear chemical-resistant, unlined boots. Neoprene boots are the best and knee-length boots offer the best protection. Do not wear leather or fabric boots and shoes, which will absorb pesticide and cannot be cleaned effectively. Wear pant legs outside the boots.

Apron: A rubber or synthetic, liquid-proof apron will protect the front of your body when mixing or pouring chemicals. Make sure it is designed to resist solvents and that it covers the body from the chest to below the top of your boots.

Face Shield: These should be made of clear plastic and attach to a hard hat. They offer additional protection for the eyes and face especially when pouring and mixing.

Respirators: Dust masks will not protect against pesticide vapours and mists. Use respirators that have been approved by the U.S. National Institute for Occupational Safety and Health (NIOSH). Do not mix and match parts from different types of respirators. Chemical cartridge respirators are recommended for outdoor use when mixing and applying pesticides. Change filters daily and replace the cartridge when you can smell a chemical odour or breathing is difficult. Use new cartridges at the beginning of each spray season and inspect the face seal while the respirator is being worn. Respirators cannot be worn securely by people with beards, moustaches or sideburns.

6. Store insecticides safely

Each province or municipality may have regulations or recommendations concerning the storage and disposal of insecticides, so make sure to check the rules for your area. Storage facilities may be subject to national and/or provincial building and fire codes and will usually require no floor drains, a containment curb to retain spills and must be built from impervious materials. They need to be isolated from other work areas and have proper ventilation and security to prevent unauthorized access. There should be absorbent materials such as activated charcoal or other chemical absorbents on the premises in case of spillage.

All pesticides should be stored off the ground on pallets or shelves and where they are out of reach of children and cannot come into contact with human food or livestock feeds. Insecticides should be segregated from herbicides and fungicides to avoid cross-contamination. Never leave chemicals in unmarked containers; it’s best to leave them in their original containers. It is very dangerous to transfer any chemicals into bottles or other containers that are usually used for food or drinks, as they could be ingested by accident.

Signs should be posted at the storage entrance warning of the contents and giving an emergency contact phone number and phone numbers for emergency services such as fire, police, ambulance and hospitals. †

About the author

Contributor

Angela Lovell

Angela Lovell is a freelance writer based in Manitou, Manitoba. Visit her website at http://alovell.ca or follow her on Twitter @angelalovell10.

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