Safety and Health in the Use of Agrochemicals

An ILO contribution to the International Programme on Chemical Safety 
(a collaborative programme of the United Nations Environment Programme the International Labour Organisation and the World Health Organization)

2. Safety and health

Safety and health in the use of agrochemicals has been one of the primary concerns of international organisations and of many governments, employers and workers and their organisations for over two decades. Some agrochemicals such as pesticides are extremely hazardous to the health of workers and the general public, and also to the environment. However, they can be used safely if proper precautions are taken. Many industrially developed countries therefore enforce strict regulations with regard to the production, sale and use of pesticides, the most hazardous group among agrochemicals. These countries have banned or severely restricted the use of some very hazardous pesticides. It may happen that other countries may be compelled to import those banned or restricted agrochemicals because of specific needs, for example to eradicate a particular pest. For these countries the economic benefits of agricultural development outweigh the risks involved. Therefore, although the safety and health problems may vary in different countries, it is important to establish clear, common procedures for the use of agrochemicals.

All those who are responsible for the production, import, storage and sale of agrochemicals have a role to play in ensuring safety and health in their use. International organisations, governments, employers and workers and their organisations, and community leaders have a fundamental role: educating agrochemical users on the hazards of the substances they handle, how these enter the body, the nature of toxic effects and the proper methods of use, and informing them of the duties and responsibilities of government authorities, other organisations and the public.

2.1. How dangerous substances can enter the body

Most agrochemicals will have an adverse effect if they enter the body. Those that are more toxic are particularly dangerous even in small amounts. Many agricultural workers die and many more are poisoned or injured each year by such substances entering the body; the main routes of absorption are through the respiratory tract (inhalation), through the skin (dermal absorption) and through the digestive. tract (ingestion) - see figures 4-6. Almost all such casualties can be avoided by preventing the entry of agrochemicals into the body.

Figure 4. Inhalation

Figure 5. Skin absorption

2.1.1. Inhalation

Breathing agrochemicals into the lungs is more likely to happen if they are in the form of gases, fine spray droplets, dust, fumes and smoke. Gases mix with the air. Others tend to remain suspended in the air for some time after release, for example by spraying. Often these particles are so small or well dispersed that they cannot be seen. Spraying agrochemicals without adequate precautions is noted to be a common cause of poisoning by inhalation. Users of fumigants and gases are particularly at risk of poisoning by inhalation.

Figure 6. Ingestion

Animal handlers are at risk from inhaling the spray created by animals which shake themselves after emerging from veterinary treatment dips.

2.1.2. Skin absorption

This is one of the most common poisoning routes. Pesticides act on pests and destroy them by penetrating the insect's skin or surfaces of plants considered to be weeds. Therefore, these substances can easily penetrate the intact human skin, if allowed to do so. Some formulations are especially hazardous if they are both toxic and contain penetrative solvents such as kerosene, petroleum products or xylene. These may pass through work clothing unnoticed by the worker. Hot working conditions which open the pores on the skin add a further risk; they allow more rapid skin absorption, as does skin damaged by cuts, abrasions or skin disease. Further, many veterinary products are chemicals that can easily be absorbed through the skin.

2.1.3. Ingestion

Contamination of the lips and mouth or accidental swallowing of agrochemicals is often caused by poor hygiene or bad practice. Failure to wash properly before eating is a common cause, as is smoking during work. Attempting to clean a blocked sprayer nozzle by putting it between the lips and blowing through it is another bad practice.

In some countries pesticides and veterinary products are decanted from large and properly labeled containers into unlabelled bottles and sold. These could subsequently be mistaken for soft drinks and consumed. Such practices should be banned. Even very small quantities of a toxic substance could cause death if ingested in this way. Inhaled toxic substances could subsequently be ingested by swallowing contaminated sputum.

2.1.4. Other

Many agrochemicals cause localised ill-effects on contact with skin or eyes even if they are not absorbed. They include some pesticides, strong acids such as sulphuric acid and strong alkalis such as caustic soda. Veterinary products may also cause problems when their use is subject to the added task of controlling the animal being treated. Accidental self-injection or needle grazing of the skin could.occur (figure 7). Such accidents may produce severe localised ill-effects, depending on the extent of skin penetration.

Figure 7. Injecting a piglet with iron to prevent anemia. (care should be taken when handling injection needles)

2.2. Classification and related measures

It has already been said that agricultural workers may be exposed to a variety of agrochemicals at work. Most of these are toxic. Therefore, all agrochemical users must know how to use the products safely by increasing their knowledge of the hazards involved, both to themselves and others. Knowledge is a powerful weapon which can be obtained by reading and understanding the label on the container. By strictly following the instructions on the label, agrochemical users will learn to protect themselves, other people, livestock, wildlife and the environment.

2.2.1. Classification

The hazards of the many thousands of agrochemicals on the market are described as toxic, harmful, corrosive, irritant, flammable, explosive or oxidising. This is called classification. Some agrochemicals may possess more than one of these hazards.

The word " toxic " has already been used in this guide to mean generally that a substance would cause ill-effects if it entered the body. In practice, the agrochemical container would It should be noted that words such as " toxic " or " harmful " have specific significance when they appear on a label. These words usually accompany a symbol.

2.2. 1. 1. Toxicity

The toxicity of a substance is mainly determined from the results of laboratory tests on small animals such as rats. These tests determine the amount of the substance that kills up to 50 per cent of a sample of laboratory test animals within a specified period. The results and hence the toxicity of the substance are expressed in two ways, depending on the test procedure: whether the animals were made to ingest or inhale the substance.

For example, a lethal dose 50 (LD 50) of 25 means that when a diet containing 25 milligrams (mg) of the substance was fed to each animal among a group of rats, half of them died after a given period assuming that each rat weighed 1 kilogram (kg). In practice the amount of toxic substance to be fed is calculated according to the body weight of the test animal. Thus the animal feed would have contained only 12.5 mg of the substance if the rats weighed half a kilogram each.

Similarly, lethal inhaled concentration 50 (LC 50) refers to the amount of the substance that will kill 50 per cent of the test population by inhalation.

In practice, the agrochemical container would carry the hazard classification symbol rather than LD 50 or LC 50 values. However, it is important to understand the relationship between the two. It should be remembered that the lower the LD 50 or LC 60 value, the higher the toxicity.

As there are many varieties of agrochemicals, the labels are also different. Different symbols in several colours, as well as the words on the label, are used to describe the harmful effects. Therefore one should understand what the symbols and words mean.

A label might have the following symbol with one of the following words:

VERY TOXIC or TOXIC

This symbol with the words "very toxic " is used to label a substance which, if it is inhaled or ingested or if it penetrates the skin, may involve extremely serious, acute (immediate) or chronic (longer-term) health risks and even death. The same symbol with the word " toxic " also denotes a highly hazardous substance. The decision to use the word " toxic " is based on LD 50 values. Therefore, extreme caution is necessary in the use of these agrochemicals and instructions on the label must be strictly followed.

Very toxic and toxic substances might also be denoted on the label by hazard class, such as class 1^a and I b respectively.

The following symbol with the word "harmful" should appear on the label of a substance which, if it is inhaled or ingested or if it penetrates the skin, may involve limited health risks. It might also be listed as an agrochemical in class II. It should be noted that class II presently denotes a," moderately hazardous" substance according to The WHO recommended classification of pesticides by hazard and guidelines to classification 1990-91.

2.2.1.2. Irritancy

The same symbol as for "harmful" but with the word " irritant " may instead be found on some labels. It is meant for a non-corrosive substance which, through immediate, prolonged or repeated contact with the skin or mucous membrane, can cause inflammation.

Other labels may specify that a substance belongs to toxicity class III, or class 4 or class 5, depending on the country classification concerned. There may be other labels with the words " does not belong to any toxicity class". Such classification is again linked to LD 50 values. It is important to follow instructions on the label in all cases.

2.2.1.3. Corrosivity

The following symbol with the word corrosive " will be found on the label of a substance which may destroy living tissues on contact with them. Severe bums on the skin and flesh might result from splashes of such substances on the body.

2.2.1.4. Flammability

The following symbol with the words "extremely flammable " denotes a liquid that would boil at body temperature and would catch fire if exposed to a flame. The same symbol with the words "highly flammable " denotes a substance which:

• may become hot and finally catch fire in contact with air at ambient temperature;
• is a solid and may readily catch fire after brief contact with the source of ignition and which continues to bum or to be consumed after removal of the source of ignition;
• is a gas and bums in air at normal pressure;
• in contact with water or damp air releases highly flammable gases in dangerous quantities;
• is a liquid that would catch fire with slight warning and exposure to. a flame.

The same symbol with the word " flammable- " denotes a substance which is a liquid that would catch fire if it were allowed to warm above room temperature. Smoking or lighting a flame should be prohibited near flammable substances. Such substances should also not be exposed to direct sunlight or allowed to warm up.

The following symbol with the word "oxidising " denotes a substance which releases a lot of heat while it reacts with other substances, particularly flammable substances.

2.2.1.5. Explosivity

The following symbol with the word "explosive" denotes a substance which may explode under the effect of a flame or if subjected to shocks or friction.

2.2.2. Labeling and relabelling

The purpose of a label is to convey a message about what the product is, who makes it and how it may be used safely and effectively. Considerable effort goes into ensuring that labels communicate to the user in a clear, concise and easily understandable manner.

It follows that if the product is to be used safely, then users must first read, understand and comply with the label. This is as important an activity as any other involving the use of the agrochemical, and must not be neglected. If users experience any difficulty in progressing beyond this first crucial stage, they should seek advice before going any further.

Some agrochemical containers are too small for a label to be glued or stuck on. In such instances there should be a leaflet securely attached to, or tagged on to, the container. Users should always ensure that a leaflet is presented with small containers. Information might also include any literature provided separately in a package, e.g. product information documents or chemical safety data sheets. This material should not be overlooked by the user.

Labeled information seeks to identify a product and describes how, when and where it should be used. It is then completed with details of potential hazards, good practices, safety precautions, first-aid instructions and advice to health personnel.

Before using any agrochemical the user should read the label and discover the information. The following should be indicated:

• hazard symbol;
• trade name of the product;
• name and quantity of active ingredient;
• purpose for which it is to be used;
• registration number when required by legislation;
• name and address of the manufacturer, distributor or agent;
• directions for use;
• safety precautions;
• warnings and statements of good practice;
• first-aid instructions and advice to health personnel;
• name and quantity of any solvent or similar material classified as hazardous;
• amount by weight or volume in the container;
• identification number of the batch or consignment;
• interval between agrochemical application and harvesting;
• any matter required by national legislation such as a reference to the requirements of specific regulations.

Users should always read the label before use or, if they do not understand the instructions, ask someone who knows. If the label is too small and cannot be read, they should use a magnifying glass or ask someone with better eyesight to read it to them. If it is torn or defaced, it may be necessary to ask the supplier for another container on which the label is legible.

Agrochemicals may be transferred from labeled containers to other containers or equipment. This may be done by suppliers who import in bulk quantities or by the user at the farm. In all instances the person responsible for the transfer must ensure that other such containers are relabelled. Relabelling must ensure that the contents are identified in a manner which will make known to the users:

• the hazards associated with their use;
• the methods of using them safely; and
• emergency procedures.

For further information reference could be made to FAO: Guidelines on good labeling practice for pesticides (Rome, 1985), and GIFAP (International Group of National Associations of Manufacturers of Agrochemical Products): F!pictograms for agrochemical labels, devised in cooperation with the FAO (Brussels, 1988).

2.2.3. Chemical safety data sheets

For each labeled agrochemical, suppliers should have a chemical safety data sheet. These should be supplied upon request to employers, agricultural officers and extension workers, and community leaders. Such data sheets contain essential detailed information regarding the identity and classification of the product, the hazards it presents and the appropriate safety precautions and emergency procedures.

2.2.4. Identification

As already mentioned, all agrochemicals should be labeled or marked (figure 8). The label should provide essential information regarding the identity, the classification, the hazards presented and the safety precautions to be observed. In addition it should cover the information on use described in section 2.2.2. Less hazardous agrochemicals, such as some fertilisers, should also be marked. Each marking should provide information on the identity and important properties relevant to the safety and health of users, as well as the name and address of the supplier.

Figure 8. All agrochemicals should be labeled or marked

In addition to the essential information on the label, less hazardous agrochemicals might be accompanied by product information documents. Such documents would be indispensable in instances where chemical safety data sheets are not provided. This information is given to the user, at no extra cost, because it is important. Every user should read, understand and follow the instructions to ensure safety and health in the use of agrochemicals. Such information should include:

• instructions on how, when and where to use the product safely and effectively;
• explanatory notes on specific matters such as dose/application rates, timing and method of treatment or application;
• warnings in some detail to prevent incorrect or inappropriate use;
• notes for observing any safety interval between the application of an agrochemical and harvesting or between the treatment of an animal and the consumption of it or its product, such as milk;
• expiry date of any product or its container if it is likely to deteriorate under normal storage conditions;
• general instructions essential to proper use such as mixing, application, compatibility with other products, preferred storage conditions, and disposal of surplus and used containers;
• description of necessary safety precautions such as the wearing of protective clothing and what to do in the event of contamination or other emergency;
• warnings about avoiding harmful effects on livestock, wildlife and the environment;
• instructions about first aid and advice to doctors indicating what to do in the event of poisoning and, where necessary, special antidotal measures with particular products;
• prohibition on the reuse of any container used for classified products, except those specifically designed and intended for such reuse.

For agrochemicals that have been marked only to indicate their identity and are without a label, the supplier should provide on request, to employers and other users, information in order to determine any precautionary measures that need to be taken during transport, handling, use and disposal.

Agrochemical users should not attempt to use the product until they have read and understood the label or the marking. They should seek the advice of the employer, agricultural extension worker or community leader in case of doubt.

When an agrochemical product is unknown and the information for its safe use is not available, then it should not be used. If inquiries fail to discover its identity, it should be disposed of safely as described later in the guide (see section 2.3.9).

Discussion and activities (sections 2.1 and 2.2)

1. Read the labels of the agrochemicals in your store.
2. Describe how they could enter your body: by inhalation, ingestion or skin absorption.
   • Which would be the most common way for the chemicals to enter the body?
   • Could they enter by all routes at the same rate?
3. Describe any cases of poisoning in your locality from (a) inhalation, (b) ingestion, (c) skin absorption, (d) all routes.
   • What lessons did you learn?
   • How can this information be shared with others in your locality?
4. Read the label of the agrochemicals in your store. Using a chart as shown below, list by category those which are: very toxic, toxic, harmful, corrosive, irritant, flammable, oxidising and explosive.
   • How many have more than one property that would affect health?
   • How many have three or more properties?
   • How many have only one?
5. Have you ever bought an agrochemical without a label? If yes, why?
   • Did the retailer sell it to you? If yes, return it to him. If the retailer confirms that the product was not labeled because it did not belong to any toxic class, check with other users before use.
   • Have you ever noticed a retailer or another user dispensing agrochemicals from a labeled container to an unlabelled one (a) for sale, (b) for storage? If yes, (c) how did you react then?
   • Describe how you would react now that you have understood about labeling and relabelling.

Some agrochemicals such as fertilisers may not be classified, In these cases ask the retailer for any information or documentation on effective use that would give essential safety information.

2.3. Safe handling and use

This major section deals with packaging, transport, transfer, storage, dispensing, pesticide application, other agrochemical applications, spillage and disposal of containers and waste.

As pesticide application is a major activity in the use of agrochemicals and also the most hazardous, precautions to be taken before, during and after application are treated separately.

Storage, management of spills and disposal are also hazardous operations. Precautions to be taken, both for the safety of users as well as the general public and the environment, are described.

Reference is also made to a series of FAO guidelines that are relevant to this section. These include:

• Guidelines for the packaging and storage of pesticides (Rome, 1985);
• Guidelines for the disposal of waste pesticide and pesticide containers on the farm (Rome, 1985);
• Guidelines on good practice for ground and aerial application of pesticides (Rome, 1988).

2.3.1. Packaging

Agrochemicals are usually supplied in packages. These may vary greatly in size, from a small bottle or box to a large metal or plastic drum. Packages are made of glass, metal, plastic or paper. In some cases they are subject to high internal pressures. Liquefied gases such as methyl bromide or anhydrous ammonia could evaporate inside the container to exert pressures on its walls. Packages need to be resistant to these pressures or the corrosive action of chemicals.

Agrochemical users should know that each package must comply with the national standards and regulations that apply to the packaging of agrochemicals. Such regulations may not exist in some countries. Therefore, users should be aware of general requirements for packaging. This information will be useful to identify properly packaged agrochemicals during purchase. Improperly packaged products could cause health risks

An agrochemical package should be so designed and constructed that:

• the contents cannot escape during handling, storage, stacking, loading and unloading;
• the contents will not deteriorate or be spoilt;
• the materials from which it is made, including fastenings such as lids, do not react with the contents to form other compounds;
• all parts of it are well, made and will not be adversely affected by changes in atmospheric conditions such as pressure, temperature and humidity;
• it is provided with a seal which is destroyed on opening for the first time, and has a fastening device so designed that it can be repeatedly refastened by the user (figure 9);
• it is labeled or marked

Figure 9. Opening a correctly designed container

Users should clearly understand that packaging and repackaging of agrochemicals is beyond their competence unless they have been trained to do so. Further, they should never attempt to repackage any agrochemical in a container not meant for it. Even if it had contained the same pesticide, there is a risk, for example, that the package may be damaged or the lid may not fasten properly. Users run a risk of contamination with toxic substances, by even trying to examine whether a container is fit for reuse.

2.3.2. Transport

Manufacturers, exporters and importers of agrochemicals should comply with international transportation and safety regulations. They might also have to comply with national regulations. Agrochemical users should be aware that such regulations exist. They are also concerned with transport, which may be from suppliers to farm or from store to field. Safe transport should ensure that:

• only products in good-quality containers are accepted from the supplier; those which are damaged or leaking should be refused;
• any vehicle transporting a product will not damage the container. Sharp edges on vehicle sides or nails which have worked upwards from floorboards should be hammered down or otherwise removed;
• a package or container is handled in a manner to avoid unnecessary collisions or violent falls. These may burst or weaken the container to cause spillage of its contents;
• any information provided with the agrochemicals such as labeling, accompanying information or data sheets is transported with it;
• random stacking is avoided during transport; for example, containers of liquid products should be transported top-side up and not be subjected to pressure by excessive loads which may cause them to burst;
• agrochemicals are isolated from other materials transported on the same vehicle;
• paper, cardboard or water-soluble packages are protected from rain or bad weather by a vehicle roof or waterproof covering;
• agrochemicals are not carried alongside the driver in either a vehicle or a tractor cab;
• drivers take extra care. They should be competent to take suitable precautions in the event of a collision or other emergency. This may involve containing spillage wherever possible and avoiding contamination of anyone providing assistance.

Figure 10 shows pesticides being loaded on to a lorry.

Figure 10. Loading pesticides on to a lorry

2.3.3. Transfer

Only in very exceptional cases should agrochemical products be transferred from one container to another. The practice has many disadvantages including the possibility that an agrochemical may mistakenly be consumed as a soft drink; this has caused fatalities in several countries. That is why the practice is banned in many countries.

Where in exceptional circumstances it is necessary to transfer agrochemicals from one container to another, the receiving container should be:

• wherever possible, the agrochemical manufacturer's container which has previously held the same product and been tested by a competent person as fit for reuse;
• of the same quality as the original container;
• properly labeled or marked;
• completely clean and empty;
• not overfilled with a liquid so as to cause spillage when pouring or due to expansion in volume by rise in temperature.

Precautionary measures should be observed when agrochemicals are transferred. Particular attention should be paid to protective clothing, removal of spillage, personal hygiene and the avoidance of contamination of any foodstuffs.

2.3.4. Storage

Agrochemicals are usually delivered to a store by the supplier or transported by the user. They are also returned to the store after partial use at the farm. During storage they are most vulnerable to theft, vandalism, accidental or deliberate misuse or the effects of extreme weather conditions. Users who have to store agrochemicals should know how to construct and maintain a place for storage, thereby ensuring their own safety and that of others. They should also take necessary action to prevent the pollution of the environment.

In general, safe and secure storage should ensure correct siting to allow easy access for the delivery of agrochemicals and transfer to farm vehicles. If the store is within a general-purpose building it should be separated from other stocks such as flammable materials. The location of the store should also take account of possible pollution risks from leaks and spillages. It should be situated away from living accommodation and surface waters such as rivers, streams and reservoirs used for the supply of drinking or irrigation water. Figure 11 shows an agrochemical store.

Figure 11. A correctly designed agrochemical store

Stores should not be located:

• in areas liable to flooding or with a potential for the pollution of underground water supply sources such as wells and boreholes; or
• in upstream catchment areas for water supply; or
• in environmentally sensitive areas;

There should be adequate capacity for storing the maximum amount of agrochemicals and provision for secure stacking and easy access.

Users should also ensure that any building used to store agrochemicals:

• is of sound construction, resistant to fire, extremes of temperature and chemical action, and impervious to liquids. Floors should be so designed as to contain spillage or leakage and have a non-slip surface which can be easily cleaned. External walls should give at least 30 minutes' fire resistance and all walls should be impervious to water, their inside surfaces smooth, easily washable and free from dust traps. If a store is of single-storey construction, the roof should be of non-combustible material which will fall in quickly and act as a vent in the case of fire;
• has suitable entrances and exits with fireresistant doors opening outwards wherever possible. Doorways should be of adequate size to allow the safe movement of materials, and interior doors should be of the swing-door type. Where stores are constructed within a general-purpose building, it is preferable that access doors open directly on to the outside of that building. Where this is not possible, access should not be shared with areas used for domestic purposes, storage of foodstuffs or keeping animals;
• could contain spillage and leakage in order to protect the external environment. In circumstances where environmental conditions are particularly sensitive, it may be necessary to construct an internal drainage system connected to a containment tank or to an encircling wall (bunding) with the capacity to hold all the agrochemicals in store;
• is kept dry and is resistant to extremes of temperature. In very hot or freezing conditions most agrochemicals would deteriorate and could even damage the containers. Similarly, dampness will weaken paper sacks, possibly resulting in spillage of the contents. The growing practice of supplying pesticides in water-soluble sachets makes it particularly important that they are stored in absolutely dry conditions;
• has adequate natural or artificial light by the provision of sufficient window area or artificial (e.g. electric) lighting. Windows should not allow direct sunlight to fall on to agrochemicals because ultra-violet light may cause deterioration of containers and contents (figure 12).

Figure 12. Avoid exposing agrochemical containers
to direct sunlight

This could be avoided by shading windows or, if building a new store, by positioning windows. Electric lights and switches should be positioned so as to avoid mechanical damage and there should be an adequate separation distance between lamps and stored agrochemicals to avoid the transmission of heat;

is properly ventilated to remove stale or contaminated air. This may be achieved by the provision of " air bricks ". Where adequate natural ventilation cannot be provided, an extractor fan should be installed. In all circumstances the removal of air should be to a point on an external wall of the building of which the agrochemical store is a part;

is suitably marked with a warning sign (figure 13) and secured against theft. Any warning sign should conform to national requirements in respect of colour, pictorial symbol and geometrical shape. If national regulations have not been specified, the skull and crossbones is generally acceptable. The security of the store is important in preventing theft or misuse of contents by unauthorised people (figure 14). The extent of security should be adequate in all foreseeable circumstances;

Figure 13. Warning I Pesticide storage I No access to
unauthorised persons!

Figure 14. Agrochemicals should be stored under
lock and key

• is well organised so that on delivery agrochemicals can be promptly stored and properly shelved and stacked in a secure and orderly way with clearly visible labels. Flammable products should be segregated by placing them in an isolated and particularly fire-resistant part of the store. Oxidising products and fumigants should, additionally, be stored in absolutely dry conditions. In any storage arrangement, care should be taken to avoid overloading shelving or compressing containers at the bottom of a stack.

Other considerations:

• water supply. A water supply should be provided nearby but not in the store. Any water supply used to fill sprayer tanks or animal treatment baths should be so designed as to avoid back siphonage;
• records. A record should be made of agrochemicals in store but kept separately in a
• safe place, so that there could be easy access to it in the event of an emergency such as fire or unauthorised use;
• first aid. Adequate first-aid facilities should be available to treat minor injuries and contamination of eyes and skin;
• fire precautions. Smoking and the use of a naked flame should be prohibited within the store. A suitable fire extinguisher in good working order should be at hand, in case of emergencies;
• washing facilities. Washing facilities should be provided close to the store for anyone who handles agrochemicals. They should be equipped with a wash-basin and clean running water, soap and towel (disposable towels are best if these are available);
• protective-clothing accommodation. Separate ventilated accommodation must be provided for protective clothing and for personal clothing. This accommodation, which is generally in the form of a cupboard or locker, must not be within the agrochemical storage area;
• storage for empty containers and solid agrochemical waste. Empty containers, other than those used for agrochemicals which react to produce gas with water, e.g. phosphide, should be washed at least three times and stored in a secure dry area with agrochemical waste; they should never be used to store food, water or other substances that may be consumed by people or animals. It should be remembered that a tiny amount of agrochemical residue from within the container could lead to serious illness or death;
• preparation areas. Where agrochemicals are dispensed into application equipment close to the store, a solid level surface should be available. They should drain only into an agrochemical containment area, to avoid polluting the surrounding environment.

2.3.5. Dispensing

Agrochemicals such as fertilisers, dusts and granules may be supplied ready for use. Others such as pesticides would need to be measured from concentrated formulations and mixed, for example with water. Dispensing agrochemicals in this way requires particular care to ensure that it is carried out safely and efficiently. This will include:

• reading the label in order to work out what equipment, such as measuring jugs, funnels, stirrers and protective clothing, is required (figure 15);
• setting out the agrochemical and dispensing equipment at an uncluttered place away from homes or livestock, and which could be cleaned of any spillage should it occur (figure 16);
• reading the label again to work out the correct dose rates and dilutions and how this can be achieved with the dispensing equipment available;
• wearing appropriate protective clothing, particularly gloves, as specified on the label or recommended in information sheets (figure 17);
• adding the dispensed agrochemical to the applicator in such a way that it is part full of water or any other diluting fluid recommended. This would prevent any accidental splash-back of the concentrated substance;
• carefully emptying packs of agrochemical dusts and powders into applicators to avoid their becoming airborne and being inhaled;
• decontaminating the utensils used for dispensing by washing or cleaning and returning to safe storage. Care should be taken to avoid inhalation, ingestion or skin absorption.

Figure 16. Set out the dispensing equipment in an uncluttered place

2.3.6. Pesticide application

The safe use of pesticides is determined by the repairs care and attention given to precautionary measures before, during and after application. It is very important to select the safest agrochemical that will act effectively with the least risk to people, livestock, wildlife and the environment.

There are different types of application equipment. The type of equipment to be used depends on:

• the scale of operation; and
• the form in which the agrochemical is applied.

It is not possible to give safety instructions about the full range of agrochemical application machinery in this guide. Some general principles, particularly with regard to the use of portable sprayers, are listed under three separate steps: pre spraying, during application and post-spraying precautions. These must be observed in order to ensure effective and safe use.

Before discussing these steps, all agrochemical users must ensure that they are properly trained as sprayer operators. If a helper is at hand he or she should also be trained. Users should ensure that the training has adequately covered the following aspects of application:

• choice of equipment;
• checking of equipment to ensure proper functioning;
• filling the applicator with the agrochemical;
• calibrating;
• operating;
• safety precautions and emergency measures in the event of malfunction or accident: cleaning, maintenance and replacement of spare parts;
• fault-finding;
• attending to simple repairs.

Users should ensure that the users' instruction manual (or similar operating instructions guide) giving detailed instructions on:

• operating procedures;
• replacement of spare parts; and
• repairs;

is always available for reference.

2.3.6.1. Pre-spraying precautions

• Read and understand labeled instructions and any other information provided with either the agrochemical, the application equipment or the protective clothing (figure 15).
• Assess the risks of application to people, animals and the environment and decide what action is necessary to reduce or eliminate them. Apart from the points covered in this guide there may be others because of the many, varied and sometimes unique circumstances of pesticide application. Seek the necessary advice before you commence application.
• Ensure that the user is competent and that he or she has received effective training in application techniques and the precautions to be observed. The user should also be familiar with the requirements under the law and guidance given in codes of practice.
• Arrange such health monitoring as may be necessary for certain hazardous agrochemicals based on their frequency of use. Do not use organo-phosphorus or carbarnate pesticides if under medical advice not to do so.
• Check application equipment to ensure that it operates satisfactorily without leaking or spilling and is calibrated for the necessary application rates.
• Check that protective clothing and other safety equipment including breathing apparatus, if required, is complete, is of the correct quality and is in good condition. Replace any items that are worn or missing.and is in good condition. Replace any items that are worn or missing.
• Decide how the work is going to be done and set up an action plan to cover its implementation, together with any emergencies that may arise.
• Check that weather conditions are satisfactory, particularly to avoid excessive wind speeds and consequent spray drift.
• Warn people nearby if they might be affected in any way or have a need to know. They may include bee-keepers, school authorities, or someone in charge of water supplies or sensitive plants or animals.
• Ensure the safe disposal of empty containers, tank washings and surplus pesticides.

2.3.6.2. Precautions during application

• Do not apply agrochemicals without adequate training.
• Wear appropriate protective clothing as prescribed on the label or information sheet for handling concentrated products.
• Avoid blow-back from granule or powdered materials when transferring container contents into the application unit. A slow, steady release causes least disturbance of air and reduces the risk of particles becoming airborne and being inhaled.
• Mix only the correct amount of agrochemical required for a particular task so as to avoid the need to dispose of any surplus.
• Handle containers carefully to prevent gurgling or spillage during pouring into an applicator. Pour correctly from large containers with the spout uppermost so as to allow air to flow into the container at the same rate as the contents flow out (figure 18).

Figure 18. Pour correctly from large containers with
the spout uppermost

• If two or more agrochemicals have to be mixed, ensure that they are compatible and without risk of a chemical reaction that would cause a "tank mix" operator hazard.
• Where protection is supplemented by an engineering control measure such as an autofill device, a closed system or a cab filtration unit, ensure that these controls are functioning correctly.
• Use an agrochemical only for the purpose for which it was intended and at the correct application/dilution rate. Ensure that an edible crop has a sufficient time interval between application and harvest so as to protect the consumer from ingesting unacceptable levels of pesticide residues.
• Do not eat, drink or smoke while applying agrochemicals.
• Ensure that dangerous practices such as putting a blocked nozzle to the mouth to blow it clear are prohibited. Clean the nozzle with water or a soft probe, such as a grass stem.
• Do not allow other workers in the field, particularly When pesticides are being applied. Take particular care to observe that children are neither allowed to spray nor are exposed to pesticides.
• Take notice of changing weather conditions, such as an increase in wind speed. This would cause drift and could blow the spray towards sensitive areas such as a drinking-water supply, resulting in health hazards. It may also blow the spray towards the operator, causing an inhalation hazard.
• Look out for overhead electricity cables and make sure that the spray boom will not come close to " live " wires (figure 19). The spray boom would act as a conductor of electricity and the operator could be electrocuted. Fatal accidents have been caused by such negligence.

Figure 19. Lookout for overhead electricity cables

• Never leave containers open and containers or application equipment unattended.
• If spillage occurs, keep everyone away until it is cleaned up and disposed of safely. This may be done by washing or using absorbent material such as soil or sawdust to soak up the agrochemical.
• Fumigants supplied as liquefied gas in pressurised cylinders are subject to special rules. Observe the rules applying to each liquefied gas under pressure.

Figures 20 and 21 show correct methods of manual spraying.

2.3.6.3. Post-spraying precautions

• Thoroughly wash hands, face and neck as well as other parts of the body which may have become contaminated. If gloves have been worn, wash them before removal.
• Return unused agrochemicals to safe storage and safely dispose of empty containers and any surplus in the application equipment.
• Decontaminate application equipment by washing it thoroughly (figure 22). The washings should be drained into a soak-away or similar chamber to be safely confined and without risk to the environment.
• Decontaminate protective clothing by thoroughly washing items such as apron, boots and face shield. Launder the work clothing each day after spraying. Gloves should be washed inside and out and allowed to dry. Respiratory protection equipment should be wiped clean.
• Bathe or wash thoroughly again after completing the above four actions.
• Complete a record of use so as to provide information about the agrochemicals used, the date and place of use and the name of the user. This is both good management practice and also a source of reference in the event of agrochemical-related illness.
• Remove warning signs when no longer necessary so that they remain meaningful and carry a message that is always relevant. The warning signs are then more likely to be taken seriously.

2.3.6.4. Re-entry

The time interval that should elapse between agrochemical application and entering the treated area for safety reasons is known as the re-entry period. It is an interval during which traces of the chemical would have been absorbed by the crop or otherwise removed from plant surfaces. In practice, the timing of the re-entry period is subject to many variables, such as the nature and toxicity of the product, its application rate, weather conditions and the surface area of the crop treated.

The minimum re-entry period should be increased substantially if entry into treated areas would result in exposure to more than an occasional skin contact or if individuals who might be susceptible had to enter. These may include children and others likely to develop skin allergies or similar adverse reactions on exposure to traces of chemicals.

If entry is required to a treated area before the re-entry period, then protective clothing appropriate to the pesticide should be worn.

The re-entry period should not be confused with the harvesting interval, which is the time between agrochemical application and the harvesting of a crop for eating.

Figure 22. Clean thoroughly all equipment used for
application of agrochemicals. Take care not to
contaminate the environment with waste water

There may be circumstances when a re-entry period for animals is also prescribed. Animals may be particularly vulnerable to the agrochemical sprayed or to the effect of the agrochemical on the vegetation that might make it taste or smell different. This may confuse the animals into eating poisonous plants which they would otherwise avoid (for example, herbicide spraying on ragwort).

Minimum re-entry periods

The following re-entry periods could provide the necessary protection under normal conditions of use:

During the time that entry to any treated area is prohibited, action should be taken to ensure that those concerned are aware of the restriction. In most cases a hazard warning sign prominently displayed at entry points such as field gateways and footpaths would be sufficient. There will, however, be circumstances where signs are inadequate. If children or adults with reading or seeing difficulties are likely to enter a sprayed area, an alternative but equally effective means of warning, such as fencing or a loudspeaker announcement, should be made.

2.3.7. Other agrochemical applications

Agrochemicals are also applied as veterinary products, fertilisers and commodity chemicals. The precautionary measures described earlier also apply to these types of product. Different methods of agrochemical application will, however, require further consideration of risks to the user.

Precautions as illustrated by the following examples should be taken:

• Animal injection treatments occasionally result in skin grazing or self-injection of the handler. Prevention requires patience and care with excitable animals. A needle set in a retractable spring-loaded sleeve which protects against accidental contact should be used.
• Animal dips for sheep or cattle are a site of intense activity and contamination. There is often much physical handling of livestock together with the splash of immersion and the cloud of spray from the animal shaking itself on exit (figure 23). The agrochemical in use generally requires a basic level of personal protection (figure 24). In addition, any person working at the site of exit might require some respiratory protection. Alternatively, a rota system of working on short shifts should be arranged.

• Hydrofluoric acid is used to clean debris and moss growth from the roof surfaces of glasshouses. Application may be by means of a brush or by spraying from a knansack sprayer. In such instances, personal protection appropriate to work with strong acids is necessary (figure 25).

Figure 25. Personal protective clothing appropriate
for working with hydrofluoric acid

• Formalin liquid is made to react with potassium permangamate to produce formaldehyde gas as a fumigant. This is a common treatment against disease-causing organisms present in some livestock buildings. The main precaution is in the mixing, which requires the measured amount of potassium permangamate to be added (last) to the required quantity of formalin; never the other way around, because the reaction and heat generated would be particularly violent.
• Strychnine and cyanide may, in certain exceptional circumstances, be approved for the control of pests such as moles or rabbits. The agrochemical is usually released underground. These extremely toxic substances should be used only by those thoroughly trained in all aspects of the work and the precautions to be observed.
• Fertilisers supplied as granules or naturally occurring rock powders may be applied by hand or by tractor-drawn machine. Applying fertilisers by hand should be avoided by using a shovel or spade. If handling is unavoidable, suitable protective gauntlet gloves may be needed.
• Liquid fertilisers are used in modern horticultural units where plants are reared hydroponically under glass roofs and individually fed through an arrangement of flexible pipes from a liquid mix and metering control unit. The concentrate may include products such as nitric and phosphoric acid which will require the handler to be protected against acids which can bum the skin. When opening acid containers, precautions should also be taken to disperse any gaseous furnes safely.
• Silage additives often include acids such as formic, phosphoric or sulphuric acid. Application is generally from a sprayer unit attached to the forage harvester. Appropriate personal protection is necessary when handling strong acids.

2.3.8. Spillage

Agrochemical spillage is both wasteful and hazardous. It should be avoided wherever possible but when it occurs it should be dealt with immediately. Some common causes of spillage are:

• containers bursting as a result of bad handling;
• container leaks due to defective packaging that does not withstand heat or humidity;
• containers being punctured during transport by sharp edges or metal studs protruding upwards through vehicle floorboards;
• careless pouring while transferring from container to applicator;
• equipment failure prior to or during application because of worn pipe couplings or hose lines.

Action in the event of spillage should include:

• taking immediate steps to avoid the spillage spreading and contaminating a wider area;
• keeping other people, animals and vehicles away from the site;
• wearing protective clothing appropriate to the use of the concentrated formulation involved;
• soaking up the agrochemical with absorbent material such as dry sand, soil or wood shavings in the case of a liquid, and removing the contaminated matter with a brush and shovel and storing securely in a bag to be disposed of safely (figure 26);

Figure 26. Using sand to contain and remove an
agrochemical spill

• removing a dry powder or granule gently with a brush and shovel and storing securely in a bag to be disposed of safely. If there is a risk of the spillage becoming airborne, some damp sand should be scattered before attempting to decontaminate;
• decontaminating any remaining traces of spillage including that on vehicles or equipment by washing down and draining the contaminated water to a safe place, or soak-up;
• bathing or thoroughly washing immediately afterwards.

2.3.9. Disposal of containers and waste

There will be circumstances when agrochemicals in store need to be disposed of safely. They may no longer be required or may be out of date, or the packaging may be broken or the container damaged. Similarly, deposits of spillage clean-ups, discarded items grossly contaminated with agrochemicals, contaminated aqueous waste such as animal dips, and empty containers must be disposed of safely.

The following general steps should be observed during disposal of waste:

Agrochemical waste should never be dumped indiscriminately

Agrochemicals should never be disposed of so as to cause any risk to people, animals, crops, water supplies or the environment.

First of all, the supplier should be asked if he would accept the waste for disposal.

Whenever possible, waste should be disposed of through a company or persons licensed to handle waste disposal. Advice should be sought from the supplier, local authority or community leader.

Accumulation of waste should be avoided. Waste should be disposed of as soon as possible.

The user should read the label on the package or container for any specific advice on waste disposal.

Empty agrochemical containers should never be reused except possibly, if in good condition, to contain an identical product transferred from a deteriorated or leaking container. All other containers should always be cleaned thoroughly before disposal. They may be cleaned in accordance with the labeled instructions. In the absence of instructions, rinse the containers in water successively at least three times. Care should be taken to ensure that the water used for rinsing does not contaminate the environment; particularly drinking-water, for example.

Liquid containers should be drained out before cleaning. Ideally cleaning should take place when a spray mixture is being prepared so that the drained material and the rinsing liquid can be added to form a part of that mixture. In other instances the rinsings should be collected for subsequent disposal elsewhere. After cleaning, the containers should be punctured in several places or crushed to make them unusable, and stored in a secure compound until their disposal is arranged. Packages of dry powders and granules must be shaken out thoroughly into a mixing vessel or the applicator tank.

Containers may be buried on premises owned or occupied by the agrochemical user. The burial site must be chosen carefully so that there can be no risk of pollution to surface water or groundwater. The approval or the advice of the local authority should be sought beforehand. The containers should be buried to a depth of at least 1 metre below the surface and below the level of any land drains (figure 27). The area used should be fenced or marked with warning signs. A record should be kept of the dates and the material buried.

Figure 27. Containers and waste should be buried at a depth of I metro

It should be possible to obtain the permission of the local authority to have a common disposal site, such as a landfill, for several users. It should allow secure burial of waste to a depth of at least I metre below the surface and away from any land drains or water courses so that there is no risk of seepage from the site which might cause pollution (figure 28).

Figure 28. Choose a safe disposal site for burying agrochemical waste

During burial of waste, protective clothing appropriate for the most hazardous product handled should be worn.

Containers in which hydrogen cyanide gassing powders or aluminium, magnesium or zinc phosphides were supplied, or which have contained these materials, should not be rinsed or cleaned with water when empty. These substances react with water to produce hazardous gases. Instead they should be filled with dry earth and punctured in several places immediately before disposal. The treated containers should then be buried. On no account should the empty containers be taken into or kept within a building.

In certain instances it may be permissible to burn lightly contaminated packaging as a means of disposal. Fumes and any smoke produced may, however, present a serious health risk and advice from the supplier of the agrochemical should be sought for any activity other than a very minor operation. The local authority should be consulted beforehand.

When waste packaging is to be burnt (figure 29), the user should ensure that:

(a) burning takes place in an open space at least 15 metres from a public highway and not in a location where any smoke produced is likely to drift over persons or livestock or move towards housing or business premises;

(b) a perforated metal drum or a fabricated incinerator is used for the bonfire;

(c) all containers are opened and placed on a very hot fire a few at a time;

(d) the fire is supervised constantly and care is taken to avoid breathing any smoke produced;

(e) the fire is extinguished after use; any residues resulting from the operation are buried as described earlier.

Figure 29. Burning agrochemical containers

On no account should packaging or containers which have held any of the following pesticide formulations be burnt: benazolin, clopyralid, 2,4-D, 2,4-DB, dicamba, dichlorprop, fenoprop, MCPA, MCPB, mecoprop, oxadiazon, picloram,sodium chlorate, 2,4,5-T, 2,3,6-TBA, triclopyr; other pesticides or formulations classed as "highly flammable pyrotechnic devices ", e.g. smokes and atomisable fluid containers under pressure. These should be buried.

Some agrochemical operations may produce liquid waste. It will then be necessary for the user to provide arrangements for safe disposal such as the construction of a soak-away which should be environmentally acceptable for the types and quantities involved. The user should consult the local authority and seek the advice of the supplier.

On completion of spraying all the equipment involved in the operation needs to be cleaned, washed and rinsed. This will produce a relatively large volume of dilute pesticide for reuse or disposal. Possible disposal routes include authorised discharge into a sewer connected to a sewage works with or without some prior treatment, or the use of a suitable soak-away. The local authority should be consulted.

Discussion and activities
(section 2.3)

1. Packaging

1.1 List the different types of package used to hold agrochemicals in your store. What are their sizes and volumes?

1.2 Have you bought any damaged packages in the past at a reduced price? If yes, would you react differently now? How?

1.3 Give two good reasons why you would not buy damaged packages of agrochemicals

1.4 List five items you consider important to ensure that a package is up to the mark.

2. Transport

2.1 Who transports your agrochemicals?

2.2 When you transport your stock, by what means: cart, open truck, lorry?

2.3 Do you regularly or occasionally transport agrochemicals with other goods such as food items?

2.4 What precautions do you take to ensure that other such items are not contaminated?

2.5 Have you experienced any contamination by spillage or container damage during transport? If yes, how did it happen? How did you manage the situation?

2.6 How can you prevent such spillage or container damage from happening in the future? List five steps you would take to ensure safety and health in the transport of agrochemicals.

3. Transfer

3.1 Have you ever had a need to transfer agrochemicals from one container to another? If yes, what precautions did you take? Whom did you consult?

3.2 List four steps you would take to ensure safety and health in the transfer of agrochemicals; to another container.

4. Storage

4.1 How big is your store

4.2 How far is it from your dwelling

4.3 Where do you keep the register of your stock? How often do you take inventories?

4.4 How many persons, other than you, are authorised to enter your store? Did you ever experience unauthorised entry? If yes, what steps will you take to prevent a recurrence?

4.5 What special precautions do you take to ensure that children do not have access to the store ?

4.6 How do you ensure the security of your store so that no unauthorised persons have access to it?

4.7 Have you ever experienced any theft or pilferage? If yes, what additional security measures did you take?

4.8 What special arrangements have you made to facilitate storage after transport?

4.9 Have you informed the local authorities, fire authorities and agricultural inspector about the siting, quantities and products stored?

4.10 Did you ever experience a spillage or a fire involving agrochemicals; in storage? If yes, how did you manage? Did you make any mistakes that resulted in (a) self-contamination, (b) contamination of others, (c) 9. contamination of waterways or any other aspect of the environment?

4.11 List seven items that you consider important to ensure safety and health in the storage of agrochemicals.

5. Dispensing

5.1 Do you normally get a helper to assist you during dispensing chemicals? If yes, is he or she trained by you? How do you ensure that he or she takes the same precautions as you do?

5.2 List five steps that you would take to ensure safety during dispensing) agrochemicals.

6. Pesticide application

6.1 Who trained you in pesticide spraying? Do you have a licence? Is there a licensing procedure or certification of competence? Did you receive a certificate after your training? If not, why was it not possible?

6.2 List the types of equipment you use.

6.3 How often do you check that the equipment is in order?

6.4 For each of the following list steps that are required to ensure safety and health: (a) before application; (b) during application; (c) after application.

6.5 What is a re-entry period? Prepare a chart showing the re-entry periods you follow after application of pesticides you are using.

7. Other agrochemical applications

7.1 Do you rear animals? If yes, list the veterinary products you use. 7.2 List the fertilisers you use.

7.3 List four precautionary measures you would take to ensure safety and health in the use of veterinary products.

8. Spillage

8.1 Describe the most recent case of an agro chemical spillage that you managed.

8.2 List five steps you consider important to ensure safety and health in managing an agrochemical spillage.

Disposal

9.1 Where is your disposal site? Could you draw an outline of it?

9.2 Are you aware of anyone in your locality using agrochemical containers for other purposes, e.g. for storing rain-water to be used during droughts? What would you advise?

9.3 How often do you dispose of your empty containers or waste?

9.4 List five steps you would take to ensure safety and health in the disposal of agrochemical containers.

9.5 Do you burn empty packages? If yes, list five items you consider important to ensure safety and health during burning.