AGRICULTURAL PESTICIDE SPRAYERS

VOLUME 1

FAO Guidelines on Equipment Quality Control and Use


Food and Agriculture Organization of the United Nations
Rome, 1998






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FAO 1998



ACKNOWLEDGEMENT

This document was prepared by T.L. Wiles and D.G. Sharp of Wiles Agriculture International, with the assistance of Professor G.A. Matthews and Mr. Evan Thornhill, IPARC, and Prof. P.C.H. Miller, Silsoe Research Institute. The valuable contribution and comments of the many international experts from both the public and private sector are also acknowledged.

Misuse of pesticides is a major impediment to sustainable agriculture and is causing immense world-wide damage to environment and human health. FAO has always advocated a reduction in the use of synthetic pesticides by promoting Integrated Pest Management and a better pesticide management through the implementation of the International Code of Conduct on the Distribution and Use of Pesticides and the Prior Informed Consent Procedure.

In order to support this FAO policy and to complement the technical activities further, the Agricultural Engineering Branch of the Agricultural Support Systems Division of FAO has over the last 3 years implemented a programme aiming to contribute to a reduction in the amount of pesticides used in agriculture and the related hazards to human health and environment by improving the quality and working conditions of pesticide application equipment as well as the skills and knowledge of farmers and operators using this equipment. This programme is meant to complement the ongoing activities of the FAO Plant Protection Service of the Plant Production and Protection Division in order to come closer to the common goal of using less synthetic pesticides in agriculture for a safer and more sustainable agricultural production.

The consideration of equipment standards is the missing link in the implementation of FAO's pesticide management package. The Plant Production and Protection Division, in close co-operation with FAO's legal office, is taking care of pesticide legislation and regulations. The legal instrument will be the basis for the registration of quality pesticides. In order to enable countries to continuously monitor the quality of products, basic formulation, control laboratories are established. However, quality pesticides as such will not have the desired effect unless they are used in a safe and efficient way. It is here that the technical aspects of application equipment will complement current and future FAO activities in pest management.

We are fully aware of the difficulties to implement standards and guidelines due to the lack of well trained staff and shortage of funds. This situation which is characterizing the reality in many FAO member countries will have to be considered in the formulation of the guidelines.

In May 1997 a meeting of the FAO Panel of Experts on Pesticide Specifications, Registration Requirements, Application Standards and Prior Informed Consent and the FAO Panel of Experts on Agricultural Engineering was held in Rome. The objective of the meeting was to finalize technical guidelines regarding the quality and use of application equipment within the framework of the FAO code of conduct on the distribution and use of pesticides and to recommend the adoption of these guidelines by FAO. For this reason experts from Africa, Asia, The Americas and Europe had been purposely invited because of their special and varied experience.

These guidelines contain the following elements:

  1. Guides to the selection of agricultural pesticide sprayers and quality standards for spray equipment
  2. Procedures for the world wide introduction of equipment certification schemes for the FAO-approved status of new spray equipment.
  3. Procedures for the organization of sustainable operator training and awareness programmes
  4. Recommendations for the organization of spray equipment test schemes for equipment in use

The working documents handed out for this panel meeting were the result of two years work of FAO in co-operation with a wide number of experts in the field of spray equipment from all over the world some of them being present at the Panel of Experts meeting. Intensive international consultations and revisions of the documents had been carried out, involving experts from research, education, extension, manufacture and international organizations.

October 1997

J. Monyo
Director
Agricultural Support Systems Division


TABLE OF CONTENT

PART ONE: FAO GUIDELINES ON EQUIPMENT QUALITY CONTROL AND USE

CONTEXTE

CONCLUSIONS AND RECOMMENDATIONS

OUTLINE OF THE FAO APPROVED STATUS SYSTEM

TRAINING MODEL

PART TWO: FAO MINIMUM STANDARDS: PORTABLE (OPERATOR-CARRIED) SPRAYERS

INTRODUCTION

GENERAL REQUIREMENTS

TANK, STRAINER AND LID

LANCE ASSEMBLY

STRAPS AND PADDING

POWER SOURCES

NOZZLES

PART THREE: FAO MINIMUM STANDARDS: VEHICLE-MOUNTED AND TRAILED SPRAYERS

INTRODUCTION

GENERAL REQUIREMENTS

TANKS

PUMPS

FILTERS AND HOSES

CONTROL VALVES AND GAUGES

BOOMS

FANS FOR AIR ASSISTED SPRAYING

ATOMISERS

PROTECTIVE CLOTHING STORAGE COMPARTMENT


PART ONE

FAO GUIDELINES
ON EQUIPMENT QUALITY CONTROL AND USE

BACKGROUND

Standards for agricultural pesticide sprayers do not exist in all FAO member countries. Existing international standards for agricultural sprayers are often incomplete or inapplicable in field situations, in many member countries.

With the objective of contributing to safer and more efficient spray equipment, FAO-AGSE has worked since 1995 on the formulation of a set of standards for the most commonly used types of spray equipment. Two types of standards have been formulated:

Minimum Standards

The immediate objective of these minimum standards is to provide a guide for FAO and other agencies to ensure that sprayers purchased offer adequate levels of safety to users, and to the environment, and are efficient and durable in operation. However, FAO member countries are encouraged to adopt these minimum standards without major delay. They should serve to eliminate substandard sprayers from the international markets. Depending upon the country and the capability of the local manufacturers they should also be introduced into the national equipment market. Although the price will always play an important part in the purchase decisions, even the cheapest models will have to comply with these minimum standards. In this way dangerous sub-standard equipment could disappear from the market and with the time also from field use.

The minimum standards are oriented towards equipment actually existing in the market and with the majority of this equipment complying with those standards. They are therefore meant for immediate introduction.

The document comprises two parts, one covering portable (operator-carried) sprayers and the second covering vehicle mounted and trailed sprayers.

Technical Standards: Sprayer Specifications and Test Procedures

These standards comprise specifications and test procedures for the major agricultural pesticide sprayers manufactured and used in FAO member states. The specifications in this document are more demanding than the above guidelines and reflect the desirable standards of spray equipment. They reflect the technical possibilities of actually existing state of the art spray equipment and take into account existing national and international standards for agricultural spray equipment.

While for some FAO member states these standards might be less demanding than actually existing national standards, for the majority of them they might still be too demanding for immediate introduction.

The objective of these standards is to provide manufacturers and governments with an appropriate, practical and consistent quality assurance system. Each country would then decide upon the form and speed of introduction. For manufacturers who's equipment is already complying with these specifications a certification system on a voluntary basis would be introduced. Equipment passing the respective tests would be awarded with an "FAO-Approved" status label which could hopefully become a quality seal in future.

In May 1997 a meeting of the FAO Panel of Experts on Pesticide Specifications, Registration Requirements, Application Standards and Prior Informed Consent and the FAO Panel of Experts on Agricultural Engineering was held in Rome. During that meeting the two standard documents were technically approved and procedures for their introduction formulated. Participants of the meeting were:

Members of AGPP/AGSE Panels of Experts:
Argentina: Mario Bogliani, INTA
Brazil: Tomomassa Matuo, UNESP
China: Tu Yu-qin, CAAS
Germany: Heinrich Ostarhild (private sector)
Malawi: Greenwell Nyirenda, Bunda College
Malaysia: Jusoh Mamat, MARDI
U.K.: Alan Lavers (private sector)
Graham Matthews, IPARC/U.K., co-author of standards
Paul Miller, SRI/U.K., co-author of standards
Resource Person, Author of standards:
David Sharp, U.K.
Resource Persons:
Ray Treichler, US Techn. Advisory Committee on ISO TC23/SC6

CONCLUSIONS AND RECOMMENDATIONS

The Workgroup on Pesticide Application Standards of the FAO Panel of Experts on Pesticide Specifications, Registration Requirements, Application Standards and Prior Informed Consent and the FAO Panel of Experts on Agricultural Engineering states, recognising an

that within integrated pest management (IPM) policies there is a need to promote safe, judicious and efficient application of crop protection agents and safeguard the environment.

Compared with the resources used in pesticide registration the panel workgroup is concerned that inadequate attention and resources have been allocated to the equally important area of pesticide application. One reason for that could be the complex and multidisciplinary nature of the subject of pesticide application.

In consequence many of the problems related with pesticide use can be related to

In recognition of such problems some countries have implemented mechanisms to certify

In order to support and strengthen the implementation of the FAO Code of Conduct on Distribution and Use of Pesticides the Panel Workgroup recognises the need for a legal framework to control quality and use of pesticide application equipment. It is also recognised that resources for implementing such a programme may be limited. It is envisaged that FAO involvement would be of a catalytic nature with the objective that these schemes must be self-financing and self-sustaining.

The Panel recommends that FAO should assist member countries in formulation and implementation of related policies and strategies to achieve these ends.

The Panel Workgroup makes the following detailed recommendations in relation to

FAO should make other international agencies as for example WHO, UNIDO, ILO regional organisations and networks such as RENPAP aware of these recommendations and liaise with them in order to implement them.

The Panel stresses the need for continuing research to improve both the design and operation of application equipment as an important component to achieve the objectives defined above and to be responsive to changes in the development of crop protection agents.

Equipment Quality

The Panel recommends:

  1. that FAO adopt, publish and disseminate the minimum standards for agricultural sprayers (Agricultural Pesticide Sprayers 2 - FAO Minimum Standards) to member countries, international organisations and industry including equipment manufacturers.
  2. where FAO is the purchasing body for pesticide application equipment, the standards must be followed.
  3. that FAO encourages member countries (including agencies involved in purchasing of pesticide application equipment) to adopt the minimum standards for application equipment as a priority.
  4. that FAO establishes an approval scheme for pesticide application equipment based on specifications and test procedures described in the FAO Technical Standards (Agricultural Pesticide Sprayers 3 - FAO Technical Standards: Sprayer Specifications and Test Procedures) as indicated in chapter 3.
  5. that high priority is given to the development of equipment that uses engineering controls to minimise the risk of operator and environmental contamination.
  6. that as this report does not cover all methods of application (including CDA*-sprayers) additional specifications and test procedures shall be the subject of a further report.

*CDA: Controlled Droplet Application

Equipment Maintenance

The Panel recommends:

  1. that FAO assists member countries to improve infrastructures that encourage availability of spare parts and improvement of equipment maintenance. This may involve various mechanisms including participation by equipment and chemical industry, dealership, their respective associations, educational institutions, commodity boards and country governments institutions
  2. that FAO assists member countries to establish the means by which a performance evaluation scheme for pesticide application equipment can be established. The preferred route of this is to ensure that the benefits of this approach are recognised by all those involved in the supply and use of such equipment.

Operator Competence

The Panel recognises that there is considerable training effort undertaken by various agencies with different objectives.

  1. It is therefore recommended that FAO assists member countries to establish improved co-ordinated and sustainable training structures to provide practical training particularly at field operator level. An example for a possible training model is outlined in chapter 4.
  2. It is further recommended that local expertise is recognised and further developed through adequate primary training. Such leading trainers must receive regular update training and recognition.
  3. The implementation of this programme should lead to a mandatory system which proves evidence of continuous operator training at field level maintaining a recognised quality standard. Such system could start with specific subgroups of operators.
  4. Recognising the contribution of the commercial sector as a training provider the panel recommends that such training should be appropriate and compatible with national programmes.

Implementation

The Panel recognizing that farmers will continue to use pesticides and other control agents, states that increased emphasis must be given to improving the efficacy of their application. In order to achieve this and to implement the report recommendations the panel feels that extra funding will be necessary.

OUTLINE OF THE FAO APPROVED STATUS SYSTEM

The Panel recognizing that farmers will continue to use pesticides and other control agents, states that increased emphasis must be given to improving the efficacy of their application. In order to achieve this and to implement the report recommendations the panel feels that extra funding will be necessary.

3. Outline of the FAO Approved Status System

To develop the FAO Approved Status System manufacturers must demonstrate that their equipment meets the requirements detailed in Agricultural Pesticide Sprayers 3 - FAO Technical Standards: Sprayer Specifications and Test Procedures. Means of demonstrating this might be

Approved test centres must be suitably equipped to carry out the test procedures outlined in the FAO Approved Status documents (Agricultural Pesticide Sprayers 3 - FAO Technical Standards: Sprayer Specifications and Test Procedures). Where a centre is not fully equipped some tests might be carried out in co-operation with other established test centres. Any approved centre must demonstrate that it has procedures for

The FAO approved status of an equipment can be shown on the equipment by a sticker for which FAO provides the design for local reproduction.

Legal implication of the approval system including the copy right of the sticker have to be verified.

Provision should be made to enable a feedback on the performance of the approval system.

FAO has the responsibility to monitor the performance of the test centres.

Funding of the FAO Approved Status System

The Panel envisages that the scheme should be self financing with manufacturers providing the resources* to show compliance with specifications (Agricultural Pesticide Sprayers 3: FAO Technical Standards - Sprayer Specifications and Test Procedures) for each model marketed. However, there will be a requirement for funding the initial set-up and maintenance within FAO.

*Some of the resources required to demonstrate this compliance may come from existing product evaluation and quality control procedures.

TRAINING MODEL

It is understood that pesticides should only be used as a last resort under integrated pest management concepts. The panel recognises that all pesticide users should undergo a minimum of training.

The objective of any training programme must be

The characteristics of good training schemes include


PART TWO

FAO MINIMUM STANDARDS: PORTABLE (OPERATOR-CARRIED) SPRAYERS

INTRODUCTION

This is part one of the FAO Minimum Standards for Agricultural Pesticide Sprayers. The aim of the series is to provide a guide for FAO and other purchasing agencies to ensure that sprayers purchased offer adequate levels of safety to users, and to the environment, and are efficient and durable in operation. At the same time FAO member countries are encouraged to adopt these minimum standards.

Price will obviously play an important part in purchase decisions, however, even the cheapest models should comply with these minimum requirements.

This guide covers the four principal operator-carried types of sprayer:

LK - Lever-operated Knapsack

MK - Motorized Hydraulic Knapsack

CS - Compression Sprayer

MB - Motorized Mistblower

Machines for applying ultra and low volume rates using spinning discs and fogging machines are not included within the scope of this document.

EQUIPMENT MAINTENANCE

The correct maintenance of all application equipment is an important component of safe and effective pesticide use. All equipment supplied must have a defined maintenance schedule and appropriate access to spare parts.

SPRAYER CHOICE

First of all, it is important that buying agencies should select the type of sprayer which is most appropriate for the purpose intended. The notes below will assist in selection.

Lever-operated knapsack sprayers

Diaphragm pumps - are suitable and are a durable option where applications are made through a single nozzle. They are also suitable for multi-nozzle booms where relatively low spraying pressures are adequate (1 bar).

Piston pumps - are suitable for single nozzle use and are preferred to diaphragm pumps for multi-nozzle use where higher pressures are required ( to 4 bar).

Underarm levers are preferred to over-arm levers except where crop conditions impede the movement of the lever.

Motorized hydraulic knapsack sprayers

These units can make good sense in high value crops for use with multi-nozzle booms where prolonged pumping, even with a piston machine, is not practical.

Compression Sprayers

Compression sprayers are necessary where field conditions make lever-operated machines impractical, for example on steep slopes and in dense crop foliage. They are also used in grain stores to treat wall surfaces.
NOTE: The output from this type of sprayer declines during the pressure cycle unless a flow control valve is fitted to the sprayer.

Motorized Mistblowers

Motorized mistblowers are used where the spray cloud needs to be projected vertically to treat trees, but may be used to spray horizontally for multi-row and bush crop spraying. They can also be adapted for granule application. They are not recommended for herbicide application.

NOZZLE CHOICE

The provision of the correct nozzle for the job enables safer and more efficient spraying. Appropriate nozzles for the intended task should be supplied with the equipment. A minimum of one nozzle type suitable for herbicide application and one for fungicide/insecticide application shall be supplied with the equipment.

Deflector nozzle (also called impact, flood or anvil nozzles) are used for single nozzle application of soil applied herbicides.

Flat fans are best for spraying products onto flat surfaces: for foliar applications, the application of herbicides to soil and insecticides onto walls for control of stored product pests.

Hollow cone nozzles are used for general spraying of foliage and give good coverage of the outer parts of a canopy (used to apply insecticides and fungicides).

Solid cone nozzles are used for spot and band spraying.

Adjustable multipurpose nozzles are not recommended for crop protection use. Spray quality is difficult to reproduce and this type of nozzle encourages operators to adjust and touch nozzles contaminated with pesticide.

HIGH PRESSURE AND DRIFT

One of the primary sources of operator hazard from hand-carried portable sprayers relates to high pressure (over 4 bar) which can produce fine droplets which are prone to drift and inhalation. High pressures can also increase hazard due to component failure leading to a major leakage of spray liquid. Therefore, a key criterion in appropriate sprayer design is the provision of systems of pressure control, within the sprayer, and at the nozzle.

This guide specifies the functional requirements for sprayers and the pressure limits recommended to minimize this potential hazard without compromising spraying efficiency.

USING THE GUIDE

For the purposes of determining minimum standards, especially in relation to safety, portable sprayers can be divided into several " Component Modules" ( Figure 1). Within each module the functional requirements, especially in relation to safety, with only minor exceptions, are the same for all sprayer types.

The guide does not aim to provide precise quality requirements and associated test procedures. These issues are addressed in the new FAO publication "FAO-Approved Status for Agricultural Pesticide Sprayers". The aim of this guide is to provide a practical aid to assist purchasing and other agencies to avoid buying or approving sprayers with quality and design limitations which could compromise operator and environmental safety.

Figure 1 - Sprayer Component Modules

Module 1
GENERAL REQUIREMENTS (LK,MK,CS,MB)

Portable agricultural sprayers should be safe, durable, reliable and capable of working efficiently under practical field conditions.

They should be robustly constructed from materials which will not obviously be prone to deterioration during field use, thereby adversely affecting safety and lowering efficiency.

All operator-carried sprayers should comply with the following:

1.1 The sprayer should have a minimum capacity of 5 litres and the total weight when full should not exceed 25 kg

1.2 No part of the outer surfaces of the sprayer should entrap spillage of liquid

1.3 There should be no sharp edges, abrasive areas, or projections which could injure the operator

1.4 The sprayer should be stable and stand upright on slopes of 1 in 15 irrespective of the amount of liquid in the tank.

1.5 The sprayer should not leak when filled to it's recommended capacity when tilted at an angle of 45 degrees from the vertical in any direction.

1.6 The sprayer should be easy to clean thoroughly both inside and outside. Rough surfaces and awkward recesses should be avoided.

1.7 Manufacturers should provide a clear, illustrated and simple instruction manual either in an accepted commercial language for a specific market OR in English, French or Spanish (FAO official languages).

1.7.1 The manual should contain procedures for:

It should also provide information on:

1.8 Servicing, maintenance, adjustment and cleaning should be easily accomplished and any specialist tools should be supplied with the sprayer.

1.9 The sprayer should be clearly and durably marked to indicate: the manufacturer's name and address, the sprayer name, model and an indication of the year of manufacture.

1.10 The manufacturer should provide evidence to the buying agency that a practical system is in place to record the sprayer specifications, make, model and year of manufacture so that spare parts can be accurately identified for a minimum of five years after the date of manufacture.

1.11 All parts of the sprayer, including the straps and padding, should be made from materials which are non-absorbent and unaffected by approved pesticide formulations and those parts of the sprayer which are exposed to sunlight should be made from materials which do not degrade on exposure to U.V. light . The relevant information should be made available to the buying agency by the manufacturer.

1.12 Pressure or flow control devices should be located outside the sprayer tank

and should be easily adjustable with gloved hands.

Module 2
TANK, STRAINER AND LID

2.1 The sprayer should have a minimum capacity of 5 litres.

2.2 The sprayer tank strainer (filter) system should be supplied with all sprayers to filter the water or spray solution as it enters the tank opening.. This should be integral for types LK,MK,MB but can be provided as part of a separate funnel for type CS.

2.3 The tank strainer mesh should be securely fitted to or form part of the strainer body.

2.4 The sprayer tank should be clearly and durably marked with:

2.5 A marking system indicating the maximum filling level should be incorporated into the tank strainer and should be clearly visible when filling.

2.6. The filler opening and strainer should permit, safe easy filling without overflowing or splashing. As a guide for LK,MK,MB, it is suggested that the strainer should be set deep into the tank opening which should be no less than 100 mm across the smallest dimension for sprayer types LK,MK,MB and 50 mm for type CS.

2.6.1 To check this point fill the sprayer from a non-profiled circular container i.e. without a special pouring lip or spout. A reasonable pouring rate to be achieved with water and without splashing or overflowing is 10 litres per 6 seconds for LK,MK,MB and 10 litres per 40 seconds for CS.

2.6.2 When filled as above, the tank strainer should not lift from its seat.

2.7 The tank-strainer mesh, or funnel mesh aperture size should not exceed 0.5 mm.

2.8 The tank strainer should be close-fitting and any gap between the strainer and the body of the tank should not exceed the filter mesh aperture size. i.e. 0.5 mm. It should be capable of removal with gloved hands.

2.9 The filler opening should be sealed with a tank lid which can be easily opened and closed with gloved hands.

2.10 The tank lid should not collect spray liquid, when fitted in position.

2.11 Either the lid or the tank should be fitted with a ventilation valve for LK,MK.

2.12 For lever-operated knapsack sprayers ( LK) , where an agitator device is fitted, this should move freely, should not catch on other parts of the sprayer and should be easily removed with gloved hands.

Extra requirements for sprayers type CS

2.13 The sprayer should be fitted with a pressure indicator device. .

2.14 The sprayer should be fitted with a pressure release valve which can easily be operated with gloved hands.

2.15 The sprayer should be fitted with a device to prevent the pressure in the sprayer exceeding 7 bar at any time.

2.16 The sprayer should be designed so that the lid (or pump) cannot be removed before any residual pressure in the tank has been released.

Extra requirement for sprayers type MB

2.17 Where the mist-blower is not fitted with a pump, the tank should be pressurized when in use to allow the liquid to flow to the nozzle, and the lid should form a complete , effective seal with the tank. The pressure in the tank and delivery hose should not exceed 0.5 bar.

Module 3
LANCE ASSEMBLY

3.1. Sprayer hoses, when bent through an angle of 180 degrees with an unsupported radius of 50 mm and at a temperature of 25 ° C must not kink (flatten) to obstruct the liquid flow. This shall be tested with no pressure in the hose.

3.2. Spray liquid hose connections should be easily adjustable with gloved hands re-useable and should not leak when they are re-used.

3.3 The lance length from the front of the hand grip to the nozzle or spray outlet should not be less than 500 mm for LK,MK,CS and less than 400 mm for MB.

3.4 The lance hose (LK,MK,CS) and the air tube and liquid hose (MB) should be of sufficient length to allow free movement and appropriate positioning of the spray outlet for spraying.

3.5 A secure "parking system" should be provided for the lance when it is not in use (LK,MK,CS).

3.6 The flow of the spray liquid should be controlled by a positive "on-off" mechanism.

3.7 Where the on/off valve is fitted with a lever , this should not measure less than 100 mm from the pivot point.

3.8 A filter which is readily removed and fitted with gloved hands, and with a mesh aperture size not exceeding 0.2 mm, should be fitted "upstream" of the on/off valve.

3.9 Interchangeable but not adjustable nozzles, ( LK,MK,CS) and flow restrictors (MB) manufactured to international standards, should be supplied with the sprayer.

3.10 The operating pressure at the nozzle should be limited to 4 bar.

3.11 At the maximum recommended working pressure and flow rate, variation in flow rate at the nozzle(s) should not exceed ± 10% (LK,MK,CS).

3.12 Where a pressure indicator is fitted, it should be downstream of the trigger valve.

Module 4
STRAPS AND PADDING

4.1 Straps should be strong and durable.

4.2 A load-bearing waist strap should be fitted to lever-operated knapsack sprayers (LK).

4.3 The load-bearing sections of shoulder and waist straps should have a minimum width of 50 mm.

4.4 The straps should be easily adjustable in the working position on the operator's back even when the tank is full.

4.5 Quick -release catches, which function efficiently even when the sprayer is full, should be fitted to straps on sprayer types LK,MK,MB.

4.6 The sprayer in the working position should be comfortable for the operator, either through the provision of a back-frame or as a result of the profile of the tank (LK,MK,MB)

Module 5
POWER SOURCES

5.1 MANUAL LEVER AND PUMP - Lever-operated Knapsack (LK).

5.1.1 The lever to operate the pump should be a minimum of 400 mm long and should have an arc of movement not more than 400 mm.

5.1.2 The sprayer and lever should be designed for both left and right hand use.

5.1.3 A hand grip with a minimum diameter of 25 mm and a minimum length of 100 mm should be firmly and durably fitted to the end of the lever.

5.1.4 Where a diaphragm or piston pump is used, the sprayer must always be fitted with a compression chamber with a volume displacement of 10 times the pump displacement.

5.2 MANUAL PLUNGER AND PUMP - Compression Sprayer (CS)

5.2.1 The pump should produce a tank pressure of 4 bar on completion of not more than 60 complete plunger strokes with the tank filled to its recommended maximum filling level.

5.2.2. The pump handle should be comfortable and convenient to use and the internal width of the handle grip should be no less than 100 mm wide and 25 mm diameter.

5.2.3 The pump pressure cylinder should be rated to withstand internal and external pressures of two times the maximum recommended operating pressure and not less than 8.5 bar.

5.2.4 The sprayer should be fitted with a locking device to secure the pump handle in its, lowest operating position and which will allow the sprayer to be carried securely by the pump handle.

5.3 THE ENGINE - Motorized Knapsack (MK) and Mistblower (MB)

5.3.1 The throttle lever should always remain firmly in position.

5.3.2 The engine should be fitted with an instant "cut-out" switch, which is readily accessible by the operator when the sprayer is in the operating position.

5.3.3 The engine should be provided with a robust starting mechanism and an alternative system in case the original system fails.

5.3.4 The exhaust should be covered by a guard and should be located on the opposite side of the unit to the operational controls.

5.3.5 The fuel tank opening and the on/off tap should be positioned to minimize the risk of fuel spilling onto the engine.

5.3.6 The spark plug should be positioned to avoid flooding of the electrodes.

5.3.7 The engine should be isolated from the knapsack frame via some form of anti-vibration mountings.

5.3.8 An easily serviceable filter should be positioned in the fuel line between the tank and the carburettor.

5.3.9 An easily replaceable dry type air filter should be fitted directly onto the carburettor intake.

5.3.10 Carburettor setting screws should be readily accessible for adjustment without the need to remove parts or use special tools.

5.3.11 The fuel tank should be durably marked with the fuel/oil ratio required.

5.3.12 Where noise levels exceed 85 dBA at the recommended operating settings, the manufacturer should include in the sprayer manual (1.7), recommendations on the use of ear defenders..

5.3.13 Where the engine drives a pump by a pulley or gearing system, adequate guards should be fitted so that no moving parts are exposed.

5.4 ENGINE - DRIVEN FAN - Mistblower (MB)

5.4.1 The fan should be fitted by direct drive to the engine.

5.4.2. The fan should be protected by a durable casing.

5.4.3 The inlet to the fan should be protected by a mesh guard with a minimum aperture size of 5mm.

Module 6
NOZZLES
Buses hydrauliques pression de liquide

6.1 HYDRAULIC PRESSURE NOZZLES

6.1.1 Nozzles fitted to or supplied with a sprayer should be manufactured to international standards. (According to ISO Standards).

6.1.2 Nozzles supplied or fitted to a sprayer should be interchangeable but not universal adjustable types.

6.1.3 The sprayer manufacturer should provide information via the sprayer manual relating to conventional nozzle designs and those supplied with the sprayer concerning:

6.2 ROTARY SPRAY GENERATING DEVICES

Where a sprayer is fitted or supplied with these devices, the following requirements shall be met:

6.2.1 The manufacturer shall provide, via the sprayer manual, details of:

6.2.2 The spray generator shall be capable of running for 50 hours continuously at the maximum speed without requiring maintenance.

6.3 OTHER SPRAY GENERATORS

Mistblowers (MB) can be fitted with air shear. The manufacturer should supply

PART THREE

VEHICLE MOUNTED AND TRAILED SPRAYERS

INTRODUCTION

This is part two of the FAO Minimum Standards for Agricultural Pesticide Sprayers. The aim of the series is to provide a guide for FAO and other purchasing agencies to ensure that sprayers purchased offer adequate levels of safety to users and to the environment and are efficient and durable in operation. At the same time FAO member countries are encouraged to adopt these minimum standards.

Price will play an important part in purchase decisions but even the cheapest models of sprayer should comply with these minimum standards.

This guide, covers all terrestrial agricultural sprayers, which are operated in conjunction with a tractor, mounted on a purpose built chassis unit or incorporated within a multipurpose agricultural/horticultural vehicle. Throughout this document, for convenience, all these types of sprayer are referred to as the "sprayer".

SPRAYER CHOICE

Generally, vehicle-mounted and trailed sprayers divide into two distinct groups according to the height and architecture of the crop/target to be sprayed:

Boom sprayers These apply the spray liquid through nozzles which are normally directed downwards and mounted on a horizontal structure (boom) and are generally used to spray low-growing arable (field) crops and weeds. Some models employ air to aid downward penetration of droplets into low-growing cereals and other crops.

Tree and bush crop sprayers These machines are designed to treat taller crops and commonly incorporate a fan to create an air stream, which is directed "sideways and upwards" to propel the droplets into the crop canopy from nozzles mounted on a boom positioned in or beside the air stream. Some models do not use an additional air stream but an arrangement of nozzles on the boom directed towards the target.

HIGH PRESSURE AND DRIFT

One of the primary sources of potential hazard from terrestrial vehicle sprayers is high pressure which can produce fine droplets which are prone to drift. High pressure can also increase hazard due to component failure leading to major leakage of spray liquid. Therefore, a key criterion in appropriate sprayer design is the provision of systems for pressure control, within the sprayer, and at the nozzle. The guide specifies the functional requirements for sprayers and the pressure limits recommended to minimize safety hazards without compromising spraying efficiency.

USING THE GUIDE

For the purposes of determining these minimum standards, sprayers can be divided into several "Component Modules" (Figure 1). Within each module the functional requirements, especially in relation to safety, are defined and presented as a simple series of numbered clauses.

This guide does not aim to describe precise quality requirements and associated test procedures. These issues are addressed in the FAO publication "FAO-Approved Status for Agricultural Pesticide Sprayers". The aim of this guide is to provide a practical aid to help purchasing and other agencies to avoid buying or approving sprayers with quality and design limitations, which could compromise operator and environmental safety.

Figure 2: Sprayer Component Modules

Module 1
GENERAL REQUIREMENTS

Sprayers should be safe, durable, reliable and capable of working efficiently under practical field conditions.

They should be robustly constructed from materials that will not be prone to deterioration during field use, thereby adversely affecting safety and lowering efficiency.

All vehicle-mounted and trailed sprayers should comply with the following:

1.1 The sprayer unit should be securely attached to the vehicle system.

1.2 All shaft drives should be adequately guarded so that no moving parts are exposed.

1.3.1 Potential trapping points, which could cause physical injury e.g. created by the boom folding or height adjustment mechanism, should be fitted with guards, where practical.

1.3.2 In positions where guards are not practical, the sprayer should be fitted with appropriate, clear warning signs.

1.4 All handles, grips or hand holds should be at least 300 mm from a hinged joint.

1.5.1 Ideally a vehicle-mounted or trailed sprayer should be fitted with a closed transfer filling system for chemical. However, where chemical filling is manual, it should be possible to add the chemical to the tank with the operator either standing on the ground or on a purposebuilt platform with a minimum floor area of 0.5 m2.

1.5.2 Reach distances for filling should not exceed 1.0 m vertically from the ground or platform and 0.3 m horizontally from the body of the person pouring the chemical. This pouring zone should be free from obstruction.

1.6 The sprayer tank(s) filling system must permit safe, easy filling without overflowing or splashing at a specified maximum filling rate.

1.7 All external parts of the sprayer should be designed so that liquid is not retained on the surface of the machine and any chemical residues which accumulate can readily be washed off by a practical cleaning routine which should be defined in the sprayer manual (see 1.12).

1.8 There should be no sharp edges, abrasive areas or sharp projections which could cause physical injury.

1.9 The sprayer should be stable when free-standing and should remain upright when positioned on a 1 in 10 slope in any direction and irrespective of the amount of liquid in the tank(s). For trailed sprayers, this should also apply when the sprayer is disconnected from the towing vehicle.

1.10 Adjustments to the sprayer, routine maintenance, drainage and cleaning should be easily carried out without the use of specialised tools.

1.11 The manufacturer should provide a clear, illustrated, instruction manual in accepted commercial language for a specific market OR in English, French or Spanish (official FAO languages).

1.12 The manual should contain procedures for:

It should also provide information on:

1.13.1 The sprayer should be clearly and durably marked to indicate: manufacturer's name and address, sprayer name and model and should indicate the year of manufacture.

1.13.2 The manufacturer should provide evidence to the purchasing agency that a practical system is in place to record the machine specifications, make, model and year of manufacture so that spare parts can be accurately specified for a minimum of five years after the date of manufacture.

1.14 All controls should be easily reached by the operator in the normal working position.

1.15 All parts of the sprayer, should be made from materials which are nonabsorbent and unaffected by approved pesticide formulations and those parts which are exposed to sunlight should be made from materials which do not degrade in U.V. light. The relevant information on materials should be made available to the purchasing agency by the manufacturer.

Module 2
TANKS

There are often several tanks or similar structures fitted to a sprayer:

2.1 the main sprayer tank(s) which contains the spraying water or diluted pesticide solution

2.2 a rinsing or flushing tank containing clean water to help wash out the inside of the main sprayer tank

2.3 a clean water tank for washing or decontaminating operators

2.4 a low-level induction tank ( hopper) to assist the safe transfer of the concentrated pesticide into the sprayer tank

MODULE 2.1 - Sprayer Tank (s), Lids and Filters

2.1.1 Sprayer tank(s) should be constructed so that they are mechanically durable.

2.1.2 Sprayer tank openings should be fitted with close-sealing lids which should be permanently and securely attached to the tank.

2.1.3 Sprayer tank lids should be fitted with a positive mechanical closure system which can be operated with gloved hands. (gloves for this purpose and where referred to elsewhere in the document, should be a minimum thickness of 0.5 mm.)

2.1.4 Sprayer tank openings greater than 400 mm in diameter, or if rectangular of more than 400 mm x 300 mm, should be fitted with a grating which cannot be removed without using tools.

2.1.5 Sprayer tank openings which can be used for filling purposes should be fitted with a strainer with a maximum mesh aperture size of 1.0 mm.

2.1.6 Sprayer tank strainers should be easy to remove and fit with gloved hands .

2.1.7 Sprayer tank strainers should be close fitting and should not lift from their seating when filling. The gap between the strainer and the body of the tank should never exceed the filter mesh aperture size of 1.0 mm.

2.1.8 Tanks should be clearly and durably marked with the "nominal" maximum recommended filling level that should not exceed 95% of the total volume of the tank.

2.1.9 The sprayer should be fitted with a means of indicating the level of liquid in the sprayer tank(s) and this level indicator system should have a scale interval of no more than 20% of the nominal volume of the tank(s) .

2.1.10 The liquid level indicator(s) should be clearly visible to the sprayer operator from the driving position and during filling.

2.1.11 The sprayer tank(s) should incorporate a safe and convenient system to enable the liquid draining from the tank to be collected or discharged for safe disposal.

2.1.12 The sprayer tank(s) should be fitted with an agitation system except where the sprayer is designed to operate exclusively with control systems in which the diluent (water) and the concentrated pesticide are separately controlled.

MODULE 2.2 - Clean Water Personal Wash Tank

2.2.1 The personal washing tank and any associated pipes or controls should handle clean water only and should be totally isolated from and independent of the main sprayer circuits that contain chemical solution.

2.2.2 The tank should have a minimum volume of 15 l.

2.2.3 The tank should be securely fixed to the sprayer.

2.2.4 The tank should be constructed from materials that will not rust or corrode thereby contaminating the water.

MODULE 2.3 - Rinse Water Tank

2.3.1 The purpose of this tank is to assist in the rinsing of the main sprayer tank. The tank and associated pipes should therefore be separate from, and independent of, the chemical circuit.

2.3.2 The tank should be designed and incorporated into the sprayer in a way that prevents it from being used by operators for personal washing or decontamination purposes.

2.3.3 The capacity of the flushing/rinse water tank should be at least 10% of the capacity of the main sprayer tank(s).

MODULE 2.4 - Induction Hopper

An induction hopper/bowl is a conveniently located receptacle into which undiluted pesticide formulations can be safely poured or placed. A flow of water is then introduced into the hopper to dissolve or dilute the pesticide and subsequently to transfer it into the main liquid flow circuit of the sprayer.

Where the sprayer is fitted or supplied with an induction hopper, it is the responsibility of the sprayer manufacturer to ensure that it meets the following requirements even though it is likely that this information will originate from the hopper manufacturer.

2.4.1 It should be designed to handle all forms of pesticide formulation that are designed to be added to water including liquids, powders, granules and soluble sachets and bags.

2.4.2 The hopper should have a minimum working volume of 15 l.

2.4.3 The hopper should be clearly and durably marked to show "the maximum recommended working level", which should be no more than 95% of the total volume of the hopper.

2.4.4 The hopper should be fitted with a lid that should be permanently and securely fixed to the hopper.

2.4.5 The hopper filling opening should have a minimum dimension of 250 mm.

2.4.6 The height of the opening through which the chemical is introduced into the hopper should be between 0.5 and 1.0 metres from the ground.

2.4.7 There should be a minimum clearance zone (i.e. an area free from obstacles) around the hopper of 0.5 m width.

2.4.8 The hopper shall include a device for cleaning the original pesticide containers such that less than 0.01% of the original contents remain in the container following a defined operating procedure (i.e. 99.99% of container contents must be removed).

2.4.9 All the components of the induction hopper should be made of appropriate materials to comply with the requirement as specified in clause 1.15.

2.4.10 All instructions related to the operation of the induction hopper should be clearly and durably marked on the sprayer or hopper.

2.4.11 The manufacturer should provide a clear, illustrated instruction manual relating to the hopper as specified in 1.11.

2.4.12 The hopper instruction manual should provide information on :

Module 3
PUMPS

3.1 The pump, at it's recommended rotational speed, should have sufficient capacity to ensure that the sprayer operates efficiently when fitted with the largest recommended size of nozzles operating at the maximum rated pressure plus an additional 20% to account for nozzle tolerances and to provide tank agitation.

3.2 It should be possible to remove the pump from the sprayer without draining the tank(s).

3.3 The pump should be permanently marked with:

Module 4
FILTERS AND HOSES

4.1 Sprayers fitted with a roller vane, piston or diaphragm pump should be fitted with a filter on the suction side of the pump with a maximum mesh aperture size of 0.5 mm.

4.2 Sprayers should be fitted with a filter in the pressure feed line with a maximum mesh aperture size of 0.5 mm.

4.3 Filters should be readily accessible for cleaning and maintenance.

4.4 It should be possible to clean all the filters without emptying the sprayer tank(s).

4.5.1 Hoses fitted to the sprayer should have a rated pressure equal to or greater than the maximum operating pressure of the sprayer plus 20% - (see Section 5.1.1 ).

4.5.2 Hoses should be durably marked to indicate the rated pressure.

4.6 Hoses should be routed so that in the event of failure, the risk of operator contamination is minimised. Hoses should not pass through the tractor/vehicle cab. When no cab is fitted, hoses close to the operator should be protected to prevent contamination in the event of failure. e.g.. by routing pipes through an outer tube with a pressure rating at least equal to that of the hose.

4.7 Any hose used to fill the sprayers should be fitted with a strainer with a mesh aperture size not exceeding 1.0 mm.

4.8 Hoses should be positioned so that there are no sharp bends (kinks) which could reduce the effective bore of the hose.

4.9 Hoses should be made from materials that are nonabsorbent and unaffected by approved pesticide formulations.

4.10 Hose connections should be easily adjustable with standard tools using gloved hands.

Module 5
CONTROL VALVES AND GAUGES

5.1.1 All sprayers should be fitted with a pressure safety device to prevent the pressure in any part of the sprayer circuit exceeding the maximum operating pressure plus 20%.

5.1.2 The pressure safety device should be designed so that when activated, all liquid flows are directed back to discharge into the main tank.

5.1.3 The design of the sprayer should ensure that, a secondary ( back-up) pressure -limiting device is fitted so that in the event of failure, or malfunction of , the main pressure control device, the pressure in the sprayer circuit will still not exceed the maximum operating pressure plus 20%.

5.2 There should be a single master control valve for turning on/off the supply to all boom sections.

5.3 The spray lines should be fitted with valves to provide independently control of the supply of pressurised spray liquid to each individual section of the boom.

5.4 Anti-drip valves should be incorporated in the sprayer circuit to minimise the loss of spray liquid from nozzles once the liquid supply to a boom section has been turned off.

5.5 To prevent back-flow by siphoning, a non return valve should be fitted to any pipe used to fill the sprayer.

5.6.1 Sprayers designed to operate with hydraulic pressure nozzles should be fitted with a pressure gauge that is clearly visible from the operator's working position.

5.6.2 The scale of the pressure gauge should allow reading with at least 0.5 bar accuracy in the pressure range from 0 - 5 bar.

5.6.3 The pressure gauge indicator should provide a stable reading.

5.6.4 The housing of the pressure gauge should be isolated from the spray liquid so that, in the event of failure leading to leakage, the operator is not contaminated.

Module 6
BOOMS

MODULE 6.1 - Field Crop Sprayers

6.1.1 Booms should be rigidly constructed so that all nozzles along the boom are supported at the same height above the target +/- 25 mm.

6.1.2 The boom should be fitted with spray pipe lines in defined sections so that the liquid supply to each section can be controlled independently (see 5.3).

6.1.3 The maximum length of a single boom section should be 6 m.

6.1.4 The height of the boom above the ground should be adjustable with a minimum range of adjustment of 1.0 m.

6.1.5 Incorporated into the mechanism for height adjustment, there should be a safety system that prevents the boom from falling and injuring the operator when the boom height is being altered

For manuallyoperated systems, this should be a self-locking anti-fall mechanism.

For powered systems, the machine should be fitted with either:

6.1.6 Sprayers with booms more than 10 m wide should incorporate a boom suspension mechanism to minimise the effects of the movements of the spray vehicle on the stability of the boom.

6.1.7 The boom should be fitted with a "breakback" device so that when any part of the outer 10% width of the boom strikes a solid obstacle when travelling forwards, the boom "breaks back" without mechanical damage to the boom structure or any other part of the sprayer. After striking the obstacle, the boom should automatically and quickly return to its original working position.

6.1.8 When folded into transport positions, the boom sections should not:

6.1.9 The sprayer should be fitted with a mechanism to securely lock the boom sections in the transport position.

6.1.10 To minimise the risk of contact with overhead power cables during the folding operation, no part of the sprayer or boom should extend to a height of more than 5.0 m above the ground. Sprayers that extend to a height of more than 3.5 m above the ground, should be fitted with a warning sign pointing out the potential hazard from overhead cables. This sign should be durable, clearly visible and easily understood by the operator.

6.1.11 The design of the boom should ensure that nozzles are protected from damage through contact with the ground.

6.1.12 Boom sprayers designed to operate with airassistance are required to meet all the standard requirements included in 6.1 to 6.11. In addition, manufacturers of this type of sprayer should include in the sprayer manual ( 1.11):

6.1.13 Where a fan is used to generate air flows, the sprayer should meet the requirements in Module 7 of this document.

MODULE 6.2 Bush and Tree Crop Sprayers

6.2.1 The spray boom (delivery arc) should be designed to enable:

6.2.2 The boom should be rigidly attached to the sprayer.

6.2.3 Where the boom is designed to operate in different positions in relation to the air stream, then clear, detailed instructions should be included in the instruction manual (1.11) describing the settings for effective operation in different crop and weather conditions.

Module 7
FANS FOR AIR ASSISTED SPRAYING

7.1 The drive to the fan unit should be able to be disconnected without affecting the mechanism for circulation and agitation of liquid in the sprayer.

7.2 The inlet to the fan should be designed and positioned so that when operating at maximum flow rate, debris is not drawn into the fan.

7.3 The lowest point of the fan inlet must be no less than 10.0 cm above the ground.

7.4 The fan should be adequately and permanently guarded and grilles, where fitted, should have a minimum mesh aperture size of 25 mm.

7.5 For selfpropelled machines fitted with a cab, the noise level, when the sprayer is operated at the maximum air flow rate, should not exceed 85 dBA at the operator's ear.

Module 8
ATOMISERS

MODULE 8.1 - Hydraulic Pressure Nozzles

Where the sprayer is fitted or supplied with hydraulic nozzles, the following requirements should be met:

8.1.1 The sprayer manufacturer should provide to the user via the sprayer manual (1.11), information on:

8.1.2 For flat fan nozzles, the nozzles support systems should include a method of ensuring correct nozzle orientation within the holder.

8.1.3 The measured output from any nozzle should be within ± 5% of the specified output at a given pressure.

8.1.4 Output from nozzles with the same identity code i.e. which claim to have the same characteristics, when fitted to a boom, should not differ by more than ± 10% of the specified output at a given pressure.

MODULE 8.2 - Twin Fluid Nozzles

These devices create a spray within a nozzle body via pressurised supplies of both liquid and air.

8.2.1 Sprayers fitted with twin fluid nozzles should be equipped with separate pressure control valves and gauges for controlling the liquid and air supplies respectively.

8.2.2 The sprayer manufacturer should provide data via the sprayer manual (see 1.11) indicating:

MODULE 8.3 Rotary Spray Generating Devices

Where the sprayer is fitted or supplied with these devices, they should meet the following requirements:

8.3.1 In addition to the requirements specified in 8.2.2 above, the manufacturer should provide via the sprayer manual (1.11) details of:

8.3.2 The spray generator should be capable of running for 50 continuous hours at maximum speed without needing maintenance.

Module 9
PROTECTIVE CLOTHING STORAGE COMPARTMENT

9.1 Where manufacturers fit protective clothing storage compartments, two compartments should be fitted; one for clean clothes and the other for contaminated clothes.

9.2 Protective clothing storage compartments should be located on the sprayer as far away as possible from the point of chemical loading.

9.3 The minimum internal dimensions of the compartments should be 450 x 450 x 300 mm.

9.4 The compartments should be clearly and durably marked: