Welcome to Module 2. In the previous lessons we hope you learned something about the kinds of risks posed by pesticides and the main international initiative designed to address these problems. In this module we would like to give you an idea of a basic approach to minimizing the risks we talked about. In the lessons included in this Module we will cover the following 7 basic responsible use rules:
Integrated Pest Management, or IPM, is characterized by management of pests rather than their control. It is a way to keep pest densities below the level where they 'eat' into farmer profits. IPM practitioners use a holistic approach to managing pests, integrating methods and ideas from a broad range of disciplines into a comprehensive program. Agricultural professionals and farmers who understand and use IPM have a powerful tool at their disposal. A definition that we like and use in our agLearn program is as follows:
"IPM is a set of management activities that farmers implement to maintain the intensity of potential pests at levels below which they become pests, without endangering the productivity and profitability of the farming system as a whole, the health of the farm family and its livestock, and the quality of the adjacent and downstream environments." (John Wightman, 1998)
One of the most fundamental premises of IPM is also one of the most important concepts of responsible use. This is that every effort should first be made to prevent the need for pesticides and that they should only be used as a last resort. Prevention, preventing the occurrence of pest problems before they can cause economic damage or require an intervention, is by far the most preferred and most responsible tactic.
For additional information on Integrated Pest Management:
For additional information on health and environmental risk assessment:
By law in most countries, all pesticides sold must have a label and users must read and obey it. In most countries, for example, it is illegal to use a pesticide on a crop unless the crop is listed on the label. It is also illegal to exceed the given rate of application on the label. Reading and understanding the label should be your starting point for responsible use once a decision has been made to use a pesticide as a control tactic.
The label should give you all the information you need for observing the remaining rules of responsible use. It will tell you how dangerous (risky) the chemical is by hazard classes (PDF 68K). It will give you some idea of what personal protective equipment you should use (precautionary statements), often through the use of pictograms. It will provide information on handling, mixing, and application including recommended equipment. It should tell you the last date before harvest that it is safe to apply the chemical. It will give you advice on what to do if the chemical is accidentally swallowed or spilled.
Below are links to some recommended articles that you can read to increase your knowledge of pesticide labels.
For additional and more complete information on all registered pesticides (including labels):
In the lesson on health risks of pesticides we presented a simple formula - Risk = Toxicity x Exposure. This relationship tells us that one way to decrease health risks is to reduce exposure to chemical pesticides. Avoiding exposure is the primary function of Personal Protective Equipment (PPE).
Choosing the proper PPE for any activity involving pesticides starts with reading the label. By law, all legally registered pesticides must tell the user if and what PPE's should be used. This information is usually in the form of Precautions statements on the label and many manufacturers also use pictograms (PDF 142K) to tell users what PPEs should be used when using their products.
There are 2 critical rules associated with PPE's. One is that if the required PPE's are not available for a particular product, or if they cannot be used for various reasons (e.g. too hot, too expensive, etc.), then the pesticide in question should not be used. The second is that if PPE's are available and appropriate then they should be used correctly.
A considerable amount of information on the proper use of Personal Protective Equipment (PPE) has been developed, collected and published by several organizations.
Personal Protection (PDF 260K 11pp.)
You are also encouraged to read the documents linked below.
Handling is any activity that involves exposure to a pesticide. This includes mixing, transporting, storing, disposing, applying, or working on pesticide equipment. Of course, the primary concern when handling pesticides is for personal safety and there are a number of safety steps that any handler should make whenever pesticides are handled. Beyond these safety steps, a handler should minimize environmental risks by analyzing the situation and making informed decisions before applying any pesticide. Some of these decisions include what pesticide to use, what formulation of a particular pesticide is best, what application procedure will give the best result with the least risk, what is the best time to apply and how much pesticide is needed. Responsible use involves selecting the least toxic and least persistent pesticide that will give the desired result. It also involves following all label recommendations when mixing, loading or applying any pesticide.
A key handling concern is the selection of the most appropriate application equipment. When equipment is selected the user should consider the type of pest, the pesticide that needs to be applied and the recommended method of application. Additional considerations are the size and type of area to be treated. Proper maintenance of application equipment is important because the applicator wants to be sure to apply only as much as is necessary and only put it where it will achieve the desired effect. Applying too little is a waste of the product, puts pesticide into the environment unnecessarily and can accelerate the development of pest resistance. Applying too much raises costs and increases risks. Applying pesticides outside the target area is again an uneconomical waste of product and poses unnecessary risks.
When you are thinking about pesticide application it might be helpful to remember the "Three E's" of application. These state that application needs to be:
For more information on pesticide application you might want to click refer to the following tutorial:
Below are also a number of supplementary readings for additional information on responsible pesticide handling.
As mentioned earlier, most pesticides are applied in order to kill, harm or repel a pest. As many pests have biological functions similar to humans it is not surprising that many chemical pesticides can also adversely affect humans. Of course, the most important thing to remember when dealing with pesticides is that prevention is the best protection and all efforts should be made to avoid exposure in the first place. To prevent accidental exposure you should:
We all know, however, that accidents happen - no matter how careful we are. People who use or work around pesticides, or people like participants in this class who are working with farmers who are using pesticides, must therefore be familiar with the signs and symptoms of poisoning and know appropriate first aid procedures that should be applied while waiting for medical help. First Aid information is generally printed on the pesticide label.
To learn more about pesticide poisoning and first aid you might want to click through the agLearn tutorial First Aid Treatment of Pesticide Poisoning (PDF 176K 12pp.)
Some other good sources of information on these topics can be found in the supplementary articles.
One of the primary regulatory responses to promoting responsible pesticide use has been to establish maximum residue levels (MRLs). Any agricultural product with residue levels above this limit may not be sold or traded. This mechanism helps to ensure that products are used according to the label and minimize environmental and health risks. MRL's are established as a part of the approval process for pesticides. Doing this involves performing trials to determine what levels of residues are present at harvest when the product is used as directed (label instructions). The maximum residue level (MRL) found in these trials is usually incorporated into national food laws and produce with levels above the MRL is considered to be illegal and must be destroyed.
There are generally very large margins of safety between allowable exposure in the diet and levels of exposure which could cause health concerns. The reason for setting and enforcing MRLs is not so much to establish safety or health limits. They are primarily a mechanism used to make sure that pesticides are used responsibly and according to the label.
Because different countries grow different crops and face different pest pressures, there is great potential for countries to set MRLs to suit their own agronomic and economic needs and not those of their neighbors or their trading partners. This situation may result in trading conflicts unrelated to health or environmental concerns. To prevent such conflict an International Body created under the UN known as 'CODEX Alimentarious' was charged with setting international standards for food including chemical residues in food.
Participants interested in the recommendations of this body should visit the link below:
Pesticide residue levels above the MRL may result from several practices: using a pesticide (or combinations of pesticides) not registered for the particular crop, over application of chemicals (never exceed the application rates or the total number of applications recommended on the label), or most commonly, chemicals applied too close to harvest time. In order for a grower to avoid having produce rejected, or in some cases even fined because of illegal residue levels, registration authorities have determined what are known as withholding periods. A withholding period is defined as the period of time that must elapse between the last application of a pesticide and:
Most pesticide manufacturers include recommended withholding periods on the product label, generally under 'Directions for Use".
Of course, the actual application of pesticides on the farm is only one activity where people need to observe responsible practices. Safety must also be a prime concern when transporting these products from the manufacturing site to the retailers and then on to the farm. After production, during their journey to users and upon reaching their final destination they will need to be safely stored. On many occasions pesticides, or their containers, will have to be disposed of in a manner that will cause the least impact to human health or the environment. Finally, accidental spills do occasionally happen that need proper attention.
Below are links to a number of documents that provide detailed information on all of these activities. Participants may also want to go through the following agLearn tutorials:
Protection According to Task (PDF 164K)
Protection of Other People (PDF 147K)