Agriculture - Use of pesticides/plant protection products

Introduction

Pesticides are chemicals designed to kill or control insects, weeds, fungi, rodents and microbes. Many pesticides have been found to be harmful to human and animal health or to the environment. As pesticides are used in many different sectors (e.g. agriculture, forestry, food industry, etc.) they may put workers in different occupations at risk of acute poisoning or occupational diseases ^[1]. This article gives a short introduction on pesticide classification, labelling and information system, presents information on related health problems, description of how exposure may take place and requirements for safe handling of pesticides with the emphasis on agricultural production.

General information about pesticides/plant protection products

Definition of pesticides

Agriculture, forestry, aquaculture, food industry, processing, transportation and storage of wood and other biological products are sectors where various pests (e.g. weeds, insects, birds, rodents, fungi, moulds, etc.) can significantly affect the quantity and quality of products. Certain species of pests can also damage buildings, installations, furniture, cloths, etc., spread infectious or cause other diseases. Therefore pest control is an important activity intended to reduce or eliminate yield losses, maintain high quality of products and prevent other undesirable effects that may be caused by pests.

Pest control is implemented by physical, chemical and biological methods and the choice of the particular method depends on various conditions (type of industry, species, amount and distribution of pests, environmental conditions, etc.). The most effective methods of pest control are based on the use of chemicals named ‘pesticides’. The largest users of pesticides are agriculture and forestry. Pesticides are also widely used in different industries, trade, storage and other sectors of economic activity and household. Adequate application of pesticides produces good results in terms of protecting products and improving quality, saving labour costs and achieving a significant economic benefit. ^[2][3]

The Food and Agriculture Organisation of the United Nations (FAO) presents following definition of pesticides:

‘Pesticide means any substance, or mixture of substances of chemical or biological ingredients intended for repelling, destroying or controlling any pest, or regulating plant growth’. ^[4]

Pesticide is a more general term than Plant Protection Product (PPP). Plant protection products are 'pesticides' that protect crops or desirable or useful plants. They contain at least one active substance and have one of the following functions:

• protect plants or plant products against pests/diseases, before or after harvest;
• influence the life processes of plants (such as substances influencing their growth, excluding nutrients);
• preserve plant products;
• destroy or prevent growth of undesired plants or parts of plants.

The term 'pesticide' is often used interchangeably with 'plant protection product', however, pesticide is a broader term that also covers non plant/crop uses, for example biocides. Within the EU legislation, there are separate legislative acts for PPP and biocides (see below) ^[5].

Classification of pesticides

In general groups of pesticides are classified and named according to the type of pest they control (Table 1).

Table 1: Classification of pesticides based on their purpose

Source: EPA ^[6]

Most pesticides listed in Table 1 are used in agriculture for one of the following purposes:

• Protecting plants or plant products against all harmful organisms (e.g. fungicides, insecticides, molluscicides, nematicides, rodenticides).
• Influencing the life processes of plants (e.g. Plant Growth Regulators).
• Preserving plant products (e.g. fumigants).
• Destroying undesired plants or parts of plants (e.g. defoliants).
• Checking or preventing undesired growth of plants (e.g. herbicides). ^[7][8]

These purposes may be briefly defined as plant protection and pesticides intended to use for these purposes compose a large group named plant protection products (PPP) ^[5]

Pesticides are also classified in accordance to how or when they work^[9]:

• Contact pesticides generally control a pest as a result of direct contact. Insects are killed when sprayed directly or when they crawl across surfaces treated with a residual contact insecticide. Weed foliage is killed when enough surface area is covered with a contact herbicide.
• Systemic pesticides are pesticides which are absorbed by plants or animals and move to untreated tissues.
• Foliar pesticides are applied to plant leaves, stems and branches.
• Soil-applied pesticides are applied to the soil. Some are taken up by roots and translocated inside the plant. Other soil-applied herbicides kill weeds by affecting the germinating seedling. Most soil applied pesticides require tillage or water to move them into the soil.
• Fumigants are chemicals that are applied as toxic gas or as a solid or liquid which forms a toxic gas. The gas will penetrate cracks and crevices of structures or soil.
• Preplant herbicides are applied to the soil before seeding or transplanting.
• Premergent herbicides are applied to the soil after planting but before emergence of the crop or weed.
• Postemergent herbicides are applied after the crop or weed has emerged.
• Eradicant fungicides control fungi that have already infected plants.
• Protectant fungicides prevent fungal infections. They retard fungal growth or prevent the organisms from entering treated plants.
• Selective pesticides will only control certain pests.
• Non-selective (or broad-spectrum) pesticides will control a wide range of pests.
• Suffocating insecticides clog the breathing system of insects and may affect eggs.
• Residual pesticides do not break down quickly and may control pests for a long time.
• Non-residual pesticides are quickly made inactive after application and do not affect future crops or pests^[9].

Pesticides can be grouped into chemical families. Pesticides with similar chemical structures have similar characteristics and usually a similar mode of action. Insecticides include following main chemical families: organochlorines (removed from the market due to their high toxicity), organophosphates, carbamates, pyrethroids ^[8]. Typical chemical families of herbicides are following: phenoxy herbicides, benzoic acid herbicides, triazines, ureas ^[10]. Substitution of chemical compounds is possible using so-called biopesticides. There are three major classes of biopesticides: microbial pesticides, plant-incorporated-protectants (PIPs), biochemical pesticides ^[11]. The active ingredients of pesticides are mixed with other compounds to improve their effectiveness, safety, handling and storage, such as solvents, mineral clays, stickers, wetting agents, or other adjuvant materials. This mixture is called ‘pesticide formulation’. Pesticide formulations can be divided into three main types: solids, liquids or gases ^[9].

Use of plant protection products in the EU

Statistical data on the overall use of pesticides are collected by Eurostat and the European Crop Protection Association (ECPA). In 2007 Eurostat produced a report on the use of PPPs in the European Union in co-operation with ECPA in 2007. The report included detailed data on EU-15 from 1992 to 2003. Separate data of the use of PPP in each EU country were also presented. Amount of used PPP was reported by ECPA as tonnes of active substances for the main PPP categories (fungicides, herbicides, insecticides, and plant growth regulators) ^[1].

Updated key figures on the consumption of pesticides are available at the Eurostat website since it is one of the 28 agri-environmental indicators that have been set up in order to monitor the integration of environmental concerns into the Common agricultural policy (CAP) of the EU. Data show that over the period 2011-2017, the sales of pesticides remained more or less stable at around 380,000 tonnes per year in the EU (EU-28) ^[13]. Furthermore on the ECPA website an interactive tool is available for consulting industry statistics on the value and volume of the plant protection production ^[14].

Placing pesticides on the market

EU legislation with regard to placing pesticides on the market

Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (CLP) substantially modified Directives 67/548/EEC and 1999/45/EC and replaced them from 1 June 2015. The Regulation adopts the UN Globally Harmonised System of Classification and Labelling of Chemicals (GHS) criteria in all EU Member States and intends to ‘ensure a high level of protection of human health and the environment as well as the free movement of chemical substances, mixtures and certain specific articles’ ^[1]. Pesticides (including PPPs) fall under the scope of CLP and therefore should be classified by their hazards, suitably packed and labelled before placing them on the market. To ensure that chemicals placed on the market do not adversely affect human health or the environment manufacturers, importers and downstream users also have to comply with the provisions of Regulation (EC) No 1907/2006 on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) ^[16][17]. REACH imposes the obligation to register any chemical placed on the market and manufacturers must identify and manage the risks linked to these chemicals. They have to demonstrate how the substance can be safely used, and they must communicate the risk management measures to the users. Pesticides that are already registered, do not require a registration based on REACH. This applies to substances used in pesticides namely:

• active substances in biocidal products that have been approved in accordance with Regulation 528/2012/EU ^[18]. The list of approved active substances used in biocidal products is available on the website of the European Chemicals Agency (ECHA) ^[19];
• active substances in plant protection products that have been approved in accordance with Regulation 1107/2009/EC ^[7]. The list of active substances in plant protection products is available on the website of the EU Commission ^[20].

It has to be noted that only active substances can be regarded as registered and that other substances used for producing the biocidal or plant protection products are subject to registration. Furthermore the other provisions of REACH such as providing information to users (e.g. Safety Data Sheets (SDS)) do apply. ^[21].

Approval of active substances in PPPs by the EU commission is based on a rigorous and lengthy (> 3 years) science-based assessment to ensure the substance is safe to use. The assessment is conducted jointly by the national authorities in EU Member States and the European Food Safety Authority (EFSA). In the first stage of the process, the active substance is assessed and possibly approved at EU level and subsequently there is an assessment and authorisation of the final products by the Member States. Data on approved substances and authorised products are reviewed periodically to reflect scientific progress or whenever needed. A new active substance is usually approved for maximum 10 years, while the renewed approval can be granted for up to 15 years ^[22].

Alongside with the regulation on the placing of the market of PPPs (1107/2009/EC) an directive has been adopted, Directive 128/2009/EC, on the sustainable use of pesticides, aimed at reducing environmental and health risks while maintaining crop productivity and improving controls on the use and distribution of pesticides ^[23]. This directive requires member states to implement national plans with quantitative objectives, targets, measures and timetables in order to reduce the risks and impact of pesticide use for human health and the environment. In order to monitor the achievements of these national plans Regulation 1185/2009 concerning statistics on pesticides, sets out rules for collecting information on the annual quantities of pesticides placed on the market and used in each Member State. A key element within the directive on the sustainable use of pesticides (128/2009/EC) is the promotion of Integrated Pest Management. Integrated Pest Management aims to keep the use of pesticides to levels that are economically and ecologically justified and which reduce or minimise risk to human health and the environment ^[24][25][26]

Basics of pesticides classification by hazard

Classification according to CLP is based on the specific basic hazardous properties of a substance determined by standard tests or other means designed to identify hazards ^[17]. The main characteristic of pesticides as hazardous substances is their toxicity. It depends on the chemical and physical properties of pesticides and defines these substances as poisonous or harmful to animals or plants. The toxicity of pesticides to humans varies in a very wide range and can be acute, sub-chronic or chronic. ^[1][27]

Acute toxicity of a pesticide is its ability to cause harmful health disorders which develop rapidly (in a few seconds, minutes, hours or a day) after absorption of a single dose or repeated exposure over a short time (e.g. one day). Such an accident may occur e.g. during mixing or applying pesticides and exposures may be referred to as acute dermal, oral or inhalation poisoning and also eye or skin irritation, skin sensitisation and neurotoxicity. Estimation of the acute toxicity of pesticide is generally based on the standard test results on rats and other animals. ^[1][27]

Pesticides are classified by the acute oral and dermal toxicity using the estimated respective lethal dose LD50 (the pesticide dose that is required to kill half of the tested animals when entering the body by oral or dermal route). Currently widely used the World Health Organisation (WHO) Recommended Classification of Pesticides by Hazard suggests allocating pesticides to the specific WHO Hazard Classes. After revision in 2009 these Classes were harmonised with the GHS Acute Toxicity Hazard Categories (see Table 2). ^[28]

The WHO presents a series of tables with individual pesticides classified according to the oral or dermal toxicity. ^[28]

The ability of a pesticide to cause adverse health effects after long-term or repeated exposure to a pesticide (e.g. when operator is frequently wetted with a pesticide spray during its application) is sub-chronic toxicity (term from few weeks to few months) or chronic toxicity (term from few months to years). Pesticides which tend to accumulate or break down slowly in human organism usually are of the greatest chronic exposure hazard. Estimation of the sub-chronic and chronic toxicity of a pesticide is based on a number of different long-term tests (periods ranging from 30 to 90 days for the sub-chronic and about 90 days to several years for the chronic toxicity) performed on animals in order to predict long-term effects which may be cause by a pesticide ^[1][27]. Such effects include:

• Carcinogenicity – production of cancer or assistance to carcinogenic chemicals.
• Oncogenicity – induction of tumor growth (not necessarily cancers).
• Mutagenicity – ability to cause genetic changes.
• Teratogenicity – ability to cause birth defects.
• Reproductive disorders – causing in e.g. reduced sperm count, sterility, and miscarriage.
• Hormone disruption – ability to disrupt the endocrine system.
• Neurotoxicity – causing in neurological problems.
• Allergenic sensitization – development of allergies to the active ingredients of pesticides.
• Damage of other particular organs or systems – damage of the lungs, liver, immune system, etc. ^[2][27]

When there is sufficient evidence of carcinogenicity in humans pesticides are additionally classified by the International Agency for Research on Cancer (IARC) ^[1][29] Hazardous effects of pesticides determined from human experience are also suitable for the purpose of classification for health hazards. When data from both humans and animals are available their quality and reliability should be evaluated ^[15].

In pursuance of presentation of the basic toxicological and other relevant information on individual pesticides essential for their safe use the Pesticide Data Sheets (PDSs) are issued. PDSs are prepared by the WHO in collaboration with the FAO and are presented on the website of the International Programme on Chemical Safety (IPCS) name INCHEM. ^[30]

Suppliers duties to ensure information

Manufacturer, importer or downstream user (natural or legal person who is not the manufacturer or the importer and who uses a substance either on its own or in a mixture in the course of his industrial or professional activities) of pesticides is obliged to classify, label and package them according to CLP before placing on the market. Distributor of pesticides is obliged to ensure their labelling and packaging in accordance with CLP before placing them on the market.

Classification by hazards

The CLP Regulation includes the following health hazard classes and categories:

• Acute toxicity (Category 1, 2, 3 and 4).
• Skin corrosion/irritation (Category 1A, 1B, 1C and 2).
• Serious eye damage/eye irritation (Category 1 and 2).
• Respiratory or skin sensitisation (Category 1).
• Germ cell mutagenicity (Category 1A, 1B and 2).
• Carcinogenicity (Category 1A, 1B and 2).
• Reproductive toxicity (Category 1A, 1B and 2) plus additional category for effects on or via lactation.
• Specific target organ toxicity (STOT) – single exposure ((Category 1, 2) and Category 3 for narcotic effects and respiratory tract irritation only).
• Specific target organ toxicity (STOT) – repeated exposure (Category 1 and 2).
• Aspiration hazard (Category 1). ^[17][31]

If applicable, pesticides also should be classified by physical and environmental hazards. The great majority of the CLP hazard categories are adopted from GHS however a few categories are not included. Therefore this should be considered when pesticides are exported to other regions outside the EU. ^[17]

Hazard communication

The Label of a pesticide is the most important source of information about a pesticide for all participants of the supply chain. Therefore according to CLP a pesticide contained in packaging should be obligatory equipped with a label including the following information (labelling elements):

• The name, address and telephone number of the supplier(s) of the pesticide.
• The nominal quantity of the substance or mixture in the packages made available to the general public, unless this quantity is specified elsewhere on the package.
• Product identifiers.
• Hazard pictograms.
• Signal words.
• Hazard statements.
• Appropriate precautionary statements.
• Supplemental information, e.g. Unique Formula Identifier ^[15]

In addition to the CLP-provisions pesticides (biocides and PPPs) have to be labelled according to their specific regulations (Biocides regulation 528/2012/EU ^[18], Plant Protection Products Regulation 1107/2009/EC ^[7] and the specific regulation on the packaging of PPP (Regulation 547/2011/EU) ^[15][32]). For instance, Regulation 547/2011 sets out specific standard phrases for PPP labels with information on risks to human or animal health or to the environment, and for safety precautions.

More specified requirements for pesticide labelling were developed and published by the FAO in the Guidelines on Good Labelling Practice for Pesticides (published in 1985 and revised in 1995) ^[33] The provisions on suggested supplemental information of the label and recommendations on writing and shaping a label are very practicable. Suggested safety precautions must cover the following:

• General precautionary statements or warnings. The following statements must appear, as a minimum, on all labels: Keep locked away and out of reach of children, Wash after use, Do not eat, drink or smoke when using the product.
• Product specific precautionary statements or warnings.
• Relevant personal protective equipment.
• Precautions when handling the concentrate (if applicable).
• Precautions during and after application.
• Environmental precautions during and after application
• A warning against the reuse of containers ^[33]

General CLP requirements are that the labels must be firmly fixed to one or more surfaces of the packaging containing the pesticide and should be readable horizontally when the package is set down normally. The labelling elements themselves (particularly the hazard pictograms) should stand out clearly from the background and should be of such size and spacing that it would be easy to read them. A fixed label is not required when the labelling elements are shown clearly on the packaging itself. ^[34]

Safety Data Sheet (SDS) is another key element of the hazard communication. The supplier of a pesticide (manufacturer, importer or downstream user) must provide the recipient of the pesticide with a SDS prepared in accordance with the REACH requirements. The SDS is not required when a pesticide is offered or sold to the general public and the users are provided with sufficient safety information, unless requested by a downstream user or distributor ^[16]

Information in the pesticide SDS (obligatory dated) should be presented using the following headings:

1. Identification of the substance/preparation and of the company/undertaking.
2. Hazards identification.
3. Composition/information on ingredients.
4. First-aid measures.
5. Fire-fighting measures.
6. Accidental release measures.
7. Handling and storage.
8. Exposure controls/personal protection.
9. Physical and chemical properties.
10. Stability and reactivity.
11. Toxicological information.
12. Ecological information.
13. Disposal considerations.
14. Transport information.
15. Regulatory information.
16. Other information. ^[16]

Pesticide Action Network (PAN) Germany developed the PAN International list of Highly Hazardous Pesticides (HHPs). The publication describes how PAN International defines Highly Hazardous Pesticides (HHPs) by identifying the hazard criterion indicators. The PAN list of highly hazardous pesticides provides a basis for starting and implementing elimination of such pesticides. ^[2]

Occupational exposure limits

Occupational exposure limit (OEL) value means the limit of the time-weighted average of the concentration of a chemical agent in the air within the breathing zone of a worker in relation to a specified reference period ^[3]. Requirement of establishing OELs has been introduced into EU legislation by Directive 80/1107/EEC on the protection of workers from the risks related to exposure to chemical, physical and biological agents at work in pursuance to help employers to control exposure to dangerous substances in the workplace ^[37]. This directive has been repealed but the principle of establishing OELs has been integrated into the Directive 98/24/EC of 7 April 1998 on the protection of the health and safety of workers from the risks related to chemical agents at work. The directive contains the general principles for preventing risks at work related to the use of chemical agents and the legal framework for indicative occupational exposure limit values (IOELV), binding occupational exposure limit values (BOELV) and binding biological limit values (BBLV). The first set of IOELVs was introduced by Directive 91/322/EEC in 1991. To date five lists of IOELVs were adopted (by Directives 2000/39/CE, 2006/15/CE, 2009/161/CE, 2017/164/EU and 2019/1831/EU. Member States are obliged to introduce national OELs based on Directives ^[34][36].

Scientific recommendations on occupational exposure limit values (OELVs) for chemicals in the workplace were prepared by the Scientific Committee on Occupational Exposure Limit Values (SCOEL) and approved by the European Commission between 1995 and 2018. SCOEL recommendations provided standards or criteria for the risk assessment and management when chemical exposure in existing workplaces occurs. From 2019, the scientific evaluation of the relationship between the health effects of hazardous chemical agents and the level of occupational exposure is conducted by the Risk Assessment Committee (RAC) of the European Chemicals Agency (ECHA) ^[4]

For any chemical for which an IOELV, a BOELV or a BBLV is established at the EU level each Member State must establish a national OELV, taking into account the EU limit value and determining its nature in accordance with national legislation and practice. National BOELV and BBLV should be based on, but not exceeding the EU limit values. ^[36][37]

For practical reasons OELs are established, based on sufficient evidence, in relation to working time, namely in relation to a reference period of a typical 8-hour working day, i.e. as 8-hour time weighted average (TWA) exposure limits. Further, they are generally set on the basis of a nominal 40-hour working week and for a working lifetime of 40 years (48 weeks/year; 5 days/week; i.e. 9600 days or 76,800 hours). The assumed respiratory volume is 10 m3/8 hours ^[39] When TWA OEL alone does not provide sufficient control of adverse health effects (immediate or delayed) a Short-Term Exposure Limit (STEL) is set. Typical examples are chemical agents causing acute harmful effects, such as respiratory sensitisation, irritation or narcosis after short-term (peak) exposure situations. The STEL is a limit value above which exposure to a chemical substance should not occur and usually relates to a 15 minute reference period. For substances which would necessitate a STEL over a very short exposure duration (i.e. less than 15 minutes) the concept of a ‘ceiling value’ might be used. Ceiling values are used for substances for which short-term exposure peaks could result in serious health effects and should not be exceeded during any part of the working exposure ^[39].

OELVs and SCOEL recommendations for individual chemical substances are a practicable source of OSH related information on hazardous substances (including pesticides) and provide employers with an effective tool for occupational risk assessment and management.

Occupational exposure to pesticides

Occupational exposure to PPPs generally is attributed to operators applying PPPs and workers entering a treated area. However there are also other groups of persons who may be under a non-dietary exposure to PPPs. All non-dietary exposure groups may be defined as follows:

• Operators are either professionals (e.g. farmers, contract applicators) or amateur users (e.g. home garden users) directly involved in activities related to the application of a PPPs.
• Workers are persons who during their work enter an area treated with a PPP or handle a crop treated with a PPP.
• Bystanders are persons entering in or being close to the area where PPP application or treatment is in process or has recently been completed and their position might lead them to be exposed to PPP.
• Residents are persons living, working or attending school or any other institution close to an area that is or has been treated with a PPP and their position might lead them to be exposed to PPP. Residents may be in such location even for 24 hours per day. ^[40]

Evidently, operators should be considered the group that will be at the greatest exposure due to the nature of following activities related to the use of PPPs:

• Opening containers, weighing, mixing and loading the product into the application machinery.
• Operation of the application machinery.
• Repair of the application machinery whilst it contains a PPP.
• Emptying and cleaning the machinery and containers after use and residue disposal.

Exposure to PPPs can also occur from spills of chemicals, leakages or faulty spraying equipment. ^[1]

PPPs are developed and should be used under very strict regulations. In turn, suppliers are obliged to provide users with all necessary information on PPP and user instructions of their safe use (see chapter 3.2). Neglecting user instructions is the main cause of the increase in operators and workers exposure ^[1].

Factors which most of all may affect exposure during working with PPPs are following:

• The form of formulation. Liquids may splash and spill resulting in direct skin contact or indirect skin contact through clothing contamination. Solids may generate dust when loading the product into the application equipment, resulting in exposure of the face and the eyes and respiratory hazards.
• Depending on the type and size of packaging in combination with the pesticide formulation opening the bags can result in some kind of exposure (splash of liquids or spread of dust).
• Weather conditions. Low relative humidity and high temperature cause more rapid evaporation of spray droplets between the spray nozzle and the target and this vapour may reach the operator. These factors also influence the perspiration rate of the human body and operator's decision whether or not to use personal protective equipment. Wind increases spray drifts and results in operators extra exposure to a PPP and contamination of areas near the treated field.
• The frequency and duration of PPPs handling both on a seasonal and lifetime basis considerably affects the exposure. ^[1]

There are three routes in which PPP may enter the body:

• Dermal (absorption through the skin or eyes).
• Oral (swallowing).
• Respiratory (inhalation).^[27]

Dermal exposure. Skin absorption is the most common route of operator’s poisoning from PPPs. The process will continue as long as the chemical remains in contact with the skin. Skin contamination may occur due to a splash, spill or drift when mixing, loading or applying a pesticide and contact with residue on application equipment, protective clothing or treated surfaces. Besides, it is very easy to transfer PPP residues from one part of the body to another. PPPs of liquid formulations are absorbed more readily than those formulated as powders, dusts or granules. When handling concentrated PPPs hazard from skin absorption increases. Absorption through wounded skin is particularly hazardous. ^[27]

Oral exposure. The most severe poisoning generally occurs when PPPs are taken in through the mouth. Chemicals may be ingested accidentally or intentionally. The most frequent accidental oral exposure is related to the keeping PPP in an unlabelled bottle or food container instead of its original labelled container. People may be poisoned when drinking PPP from such bottle or by drinking water stored in contaminated container. Workers handling PPPs or application equipment can consume PPP residues from unwashed hands during eating or smoking. PPP may enter applicators mouth when trying to clear a spray line or nozzle by blowing. ^[27]

Respiratory exposure. Inhaled PPPs may cause serious damage to nose, throat and lung tissues or be transferred through the lungs into the bloodstream. Absorption of PPPs through lung tissues is very rapid and complete therefore hazard of poisoning from respiratory exposure is considerable. Respiratory tract may be exposed to PPPs by inhalation of powders, airborne droplets or vapours, namely:

• The powder which usually contains concentrated active ingredient may be inhaled during opening containers, weighing and mixing operations.
• Inhalation of PPP spray droplets during use of low pressure application equipment is fairly low because most droplets are too large to remain airborne. However, when high pressures or fogging equipment is used, the droplets are in the mist or fog size-range and can be carried on air currents for a large distance thus considerably increasing the potential for respiratory exposure.
• Use of fumigants due to effectiveness of their toxic vapours for a pest control also has the highest hazard with respect to worker exposure to vapours. Some non-fumigant PPPs may also produce vapours being toxic to applicators or bystanders. The hazard is much higher in enclosed spaces with limited air movement (e.g. unventilated storage areas, greenhouses, etc.). Increasing temperature causes higher vapour levels therefore it is recommended that PPPs should not be applied when air temperatures are above 30°C. ^[27]

In order to determine the seriousness of the poisoning due to exposure to a PPP it is necessary to be aware of the pesticide poisoning symptoms. General symptoms indicating possible pesticide poisoning are following:

• Mild poisoning: headache, dizziness, weakness, fatigue, nervousness, loss of appetite, thirst, nausea, irritation of throat and nose, eye irritation, constriction of pupils, blurred vision, skin irritation, changes in mood, loss of weight.
• Moderate poisoning: abdominal cramps, vomiting, diarrhoea, excessive salivation, constriction in throat and chest, abdominal cramps, rapid or slow pulse, excessive perspiration, trembling, muscle incoordination, mental confusion and any mild symptoms.
• Severe poisoning: inability to breathe, chemical burns on skin, respiratory distress, loss of reflexes, uncontrollable muscle twitching, unconsciousness, convulsions and any mild or moderate symptoms.

Pesticide poisoning may be obvious when a person is exposed to very high levels of PPP concentration. However very often it is difficult to recognize pesticide poisoning because the symptoms may appear after some time only, be similar to those of other troubles (e.g. flu, cold, food poisoning, etc.) and vary from person to person. ^[27] For the possible health effects related to exposure to PPPs see chapter 'Basics of pesticides classification by hazards'.

Prevention in the workplace

In the case of use of plant pesticides specific requirements for preventing occupational accidents and ill health related to the presence of hazardous chemical substances at the workplace should be applied. Directive 98/24/EC ^[36] and related national OSH legislation oblige the employer first to determine whether any hazardous chemical agents (in the concrete case – PPPs) are or will be present at the workplace. It is obvious that application of PPPs causes such presence therefore the employer must assess any risk to the safety and health of workers arising from the presence of PPPs. Where the results of the assessment indicate a risk to the safety and health of operators and workers (see chapter 4) the specific prevention measures should be applied in order to manage the risk (to eliminate or reduce it to a minimum). Selection of the prevention measures should be done keeping their hierarchy ^[36].

Risk assessment

Risk assessment of the PPPs impact on human health is the most important step of the risk management when using PPPs. But carrying out a risk assessment can be challenging because of differences in the periods and the levels of exposure, type of PPPs (regarding toxicity), mixtures or cocktails used in the field, and the geographic and meteorological characteristics of the agricultural areas where PPPs are applied ^[41]. Therefore, employers should follow a step by step approach of risk management and make use of tools for risk assessment for dangerous substances (e.g. well-known tools are the International Chemical Control Toolkit of ILO, the British COSHH-Essentials, the German EMKG (Einfaches Massnahmenkonzept Gefahrstoffen) and the Dutch Stoffenmanager). Risk assessment should be done for each operation of PPPs use.

When assessing the risk it is particularly important taking into consideration the following:

• Hazardous properties of PPPs.
• Information on safety and health provided by the supplier (e.g. the relevant label and SDS.
• The level, type and duration of exposure.
• The circumstances of work involving such agents, including their amount.
• Occupational exposure limit values or biological limit values.
• The effect of preventive measures taken or to be taken.
• Where available, the conclusions to be drawn from any health surveillance already undertaken. ^[36]

The total operator or worker exposure to PPPs is the sum of all exposures resulting during different working situations ^[42]. Besides, all exposure groups (operators, workers, bystanders and residents) should be considered.

After the risk assessment the next steps of the risk management (risk control, review and update of the process, and documentation of the process) are undertaken.

Preventing or adequately controlling exposure to PPPs involves a combination of following measures listed in order of priority

• Measures at source (e.g. elimination or substitution).
• Technical, engineering measures.
• Organisational measures.
• Personal protective equipment (PPE).

Measures at source

Measures at source may prevent the release of dangerous substances which are in PPPs, or reduce its release and dispersion as much as possible, or change the release in such a way that it is less harmful.

The best way to eliminate PPPs in the agricultural production is transforming the conventional farming into organic farming. Typical organic farming practices related to the use of PPPs include:

• Strict limits on chemical synthetic pesticide use, livestock antibiotics, food additives and processing aids and other inputs.
• Absolute prohibition of the use of genetically modified organisms.
• Choosing plant and animal species that are resistant to disease and adapted to local conditions. ^[43]

About 1% of the agricultural land in the world is organic while in the EU this number is 6.2 percent ^[44]. The substitution of PPPs may be accomplished through the replacement of hazardous substances by less hazardous or non-hazardous substances or technological or organisational measures ensuring achievement of an equivalent pest control results. There are different alternatives to PPPs including various methods of cultivation, use of biological pest controls (such as pheromones and microbial pesticides) and methods of interfering with insect breeding. The cultivation practices include growing multiple types of plants, crop rotation, planting crops in areas where the pests that damage them do not live, timing planting according to when pests will be least problematic, and use of the trap crops that attract pests away from the real crop. Release of other organisms that fight the pest is another alternative to the PPPs use. These organisms can include natural predators or parasites of the pests. One more alternative to PPPs is the thermal treatment of soil through steam. ^[10]

Some other alternatives to PPPs are to:

• Choose plants resistant to insects and diseases.
• Eliminate lost plants, which can be shelter to insects and diseases.
• Make weed control before blossom.
• Use physical controls such as traps, barriers, and mechanical removal.
• Kill soft body insects (e.g. blight, grub) by spraying plants with insecticide soap.
• Use natural insecticide like Bacillus thuringiensis (Bt).
• Eliminate food sources for pests.
• Plant local origin plants.
• Deliberate possibility to accept a few weeds, instead to pursue “perfect lawn".
• Use animals, like goats (especially for blackberry cleaning). ^[45]

The aforementioned measures may be considered as a part of initiative named the sustainable use of pesticides that means: to use only amounts of pesticides which are really necessary. Legal background of the sustainable use of pesticides is Directive 2009/128/EC establishing a framework for the Community action to achieve the sustainable use of pesticides ^[23]. According to the Directive achievement of a sustainable use of pesticides should be implemented “by reducing the risks and impacts of pesticide use on human health and the environment and promoting the use of integrated pest management and of alternative approaches or techniques such as non-chemical alternatives to pesticides" ^[23] (see also above).

Technical, engineering measures – machinery and equipment for plant protection product application

When measures at source cannot sufficiently reduce the release of dangerous substances, technical measures for reducing dispersion of chemicals and consequently exposure of workers should be (additionally) considered. As the heaviest exposure occurs during handling of the pesticide concentrates, appropriate facilities must be provided.

According to Directive 2009/127/EC amending Directive 2006/42/EC with regard to machinery for pesticide application “Machinery for pesticide application" means machinery specifically intended for the application of PPPs within the meaning of Regulation (EC) No 1107/2009. This machinery includes self-propelled, towed, vehicle-mounted, semi-mounted, airborne and stationary machinery intended for PPPs application, both for professional and non-professional use, as well as powered or manually-operated portable and handheld machinery with a pressure chamber. The Directive defines essential health and safety requirement for machinery. Manufacturers of machinery for pesticide application are responsible for certifying the conformity of their machinery to the provisions of the directive including the safety and health requirements. Products that meet these requirements bear the CE-marking. The requirements concern ensuring the application control and monitoring, safe machinery filling, emptying and application of PPP (including application rate, distribution, deposition and drift of PPP, tests and losses during stoppage), proper machinery maintenance and inspections, and also the information which should be provided in the machinery instructions. ^[46][1]

In order to enable manufacturers to comply with these requirements the European standardisation organisations are obliged to draw up harmonised standards providing detailed specifications for aforementioned machinery ^[47]. Examples of such standards are: EN-ISO 16122-2:2015: Agricultural and forestry machinery - Inspection of sprayers in use - Part 2: Horizontal boom sprayers and EN-ISO 16122-3:2015 Agricultural and forestry machinery - Inspection of sprayers in use - Part 3: Sprayers for bush and tree crops

Organisational measures

Organisational measures generally are not very strictly defined and may in fact include several types of measures.

Information and training of all workers is a particularly important measure for minimising exposure in the case of use of PPPs. Importance of information and training of workers exposed to chemical agents is emphasised by Directive 98/24/EC which obliges the employer to ensure that workers and/or their representatives should be provided with:

• The data obtained from the assessment of risks related to use of chemicals (e.g. PPPs) and information on the change in these data after major alteration at the workplace.
• Information on the hazardous chemical agents occurring in the workplace (the identity of the agents, the risks to safety and health, relevant occupational exposure limit values and other legislative provisions).
• Training and information on appropriate measures and actions to be taken in order to safeguard themselves and other workers at the workplace.
• Access to any safety data sheet available at the enterprise. ^[36]

According to Directive 2009/128/EC Member States must set up systems of both initial and additional training for distributors, advisors and professional users of PPPs and certification system. The latter is necessary to record such training so that those who use or will use pesticides are fully aware of the potential risks to human health and the environment and of the appropriate measures to reduce these risks ^[23]. Thus, the essential safety requirement is that persons can handle PPPs only if they have an appropriate certificate of competence. The type of certificate needed will depend on the used product and individual circumstances of the use. Persons who have no certificate of competence must be supervised by a person who has the necessary certificate and knowledge ^[48]. Besides, training activities for professional users of PPPs may be coordinated with those organised in the framework of Regulation (EC) No 1698/2005 ^[2].

Training workers for safe work practices on the basis of risk assessment also is an important part of risk management (see chapter 5.1). Trained workers will be aware of the risk of exposure and of what they need to do to control their exposure, therefore they will work not only more efficiently, but also more safely and with less risk to their health.

In most Member States there are prepared guidelines, recommendations or comprehensive, statutory codes of practice for using PPPs which may be helpful for the training purposes and help to comply with an appropriate legislation ^[50] (also see links for further reading).

Personal hygiene is extremely important when handling PPPs as it may have a substantial impact on the workers exposure. General requirement is that during work workers should not touch their face or other bare skin with dirty hands or gloves. Persons working with PPPs have at least to wash face and hands before eating, drinking, smoking or going to the toilet. Special attention to personal hygiene must be paid during the aforementioned worker training.

Health surveillance means the monitoring of persons in order to identify changes (if any) in their health due to exposure to hazardous substances. The purpose of this preventive measure is to protect workers’ health by detecting at an early stage any harm which may be caused by the exposure. Therefore, according to Directive 98/24/EC Member States must introduce arrangements for carrying out appropriate health surveillance of workers for whom the results of the risk assessment reveal any risk to health arising from the presence of chemical agents. ^[36]

Risk assessment of the PPPs possible impact on human health should identify the need to check the health of employees who could be exposed to these PPPs. In turn the health surveillance helps employers to judge the effectiveness of risk assessment and its control measures.

Before applying preventive measures during the use of PPPs results of health surveillance should be taken into account where together:

• The exposure of the worker to a PPP is such that an identifiable disease or adverse health effect may be related to the exposure.
• There is a likelihood that the disease or effect may occur under the particular conditions of the worker's work.
• The technique of investigation is of low risk to workers.

Where a binding biological limit value for a PPP has been set, health surveillance should be a compulsory requirement for work with this PPP. ^[36]

Arrangements should be made to ensure that any exposed person can easily report any symptoms to a medical officer or a supervisor, who will then bring the complaint to the attention of a medical officer. Any undue prevalence of illness not associated with well-recognized signs and symptoms of poisoning by the particular PPP should be noted and reported to the appropriate health authorities. Individual health and exposure records should be made and kept up-to-date for each worker who undergoes health surveillance. ^[36]

Otherorganizational or administrative measures can be used to reduce the exposure to PPPs such as:

• Job rotation of workers.
• Timing the job so that workers are fewer exposed.
• Use of safety signs, for instance restricting entry of non-authorised persons (warning signs after the PPPs application in the field or storage).

Use of personal protective equipment (PPE)

Personal protective equipment (PPE) is the least effective risk control measure providing a barrier between the worker and the hazard.

The personal protective equipment for the work with PPPs includes:

• Head protection.
• Eye and face protection.
• Respiratory protection.
• Protective gloves.
• Protective clothes.
• Protective footwear.

The main requirements for the use of PPE are following:

• Protective equipment should be in a good condition and fit well.
• Filter or cartridge of respiratory equipment should be changed at the specified time.
• Gloves must be protective, fit the hands comfortably and be flexible enough to grip PPP containers firmly.
• Gloves and boots should be washed before removal in order to avoid self-contamination.
• The clothes should be resistant against the PPPs used and washable.
• Garments should be washed separately from other clothes.
• Protective clothing should be stored in a clean, dry and well-ventilated room separated from other clothing or living accommodation.
• Contamination of work clothes through/by protective equipment should be avoided.
• Personal protective equipment should be used even on a hot and humid day. ^[42]

Generally, the Safety Data Sheet of a PPP may be helpful in selecting the proper PPE.