LERAP Equipment Accreditation

Procedures for the submission and review of data packages and the awarding of LERAP-low drift star rating for ground based arable crop sprayers

1. Introduction

An important feature of the Local Environmental Risk Assessments for Pesticides (LERAP) requirements relates to the ability to reduce the width of a buffer zone defined to protect surface water from contamination by plant protection products when the results from a local risk assessment indicate that it is safe to do so. One of the factors that is taken into account as part of the LERAP assessment is the use of technical (operational and engineering) controls to reduce the amount of spray drift produced during application that would deposit within the local environment. Spray application systems that have been shown to have such a drift reducing characteristic will be awarded a 'LERAP-Low Drift Star Rating' which can then be used in the local drift risk assessment procedures. This paper outlines the procedures that need to be followed by those offering to supply spraying equipment for use in the UK and for which they wish to gain a 'LERAP-Low Drift Star Rating' under the arrangements relating to the LERAP scheme.

2. Definitions

LERAP-Low Drift Star Ratings will be awarded to:

Star ratings will be awarded by comparing the levels of drift from candidate sprayers or spray generators with corresponding drift levels from a reference system. This reference system shall be defined as an open structured boom construction fitted with F110/1.2/3.0 nozzles, manufactured from stainless steel, operating with a nozzle height above the target of 0.5 m. The reference sprayer will have the same nozzle specification along the whole length of the boom ie no special nozzle design will be used at the end of the boom. The reference sprayer shall be fitted with a boom suspension arrangement to provide isolation from both the rolling and yawing motions of the spray vehicle. Reference performance will be based on spraying of water and of a 0.1% solution of a non-ionic surfactant.

Star ratings will be awarded based on the criteria defined below.

Terminology and Drift Performance (measurable as ground deposit)

3. Data Requirements

Applications for LERAP-Low Drift Star Ratings relating to either complete sprayers or spray generators will require the submission of a data package that must include:

  1. a full technical description of the sprayer or spray generation system for which a LERAP-Low Drift Star Rating is to be claimed;
  2. a definition of the operational settings and conditions (or ranges within an operational envelope) within which a LERAP-Low Drift Star Rating is to be claimed together with evidence of written instructions to operators as to how such settings shall be achieved;
  3. evidence to show the level of drift reduction that can be achieved with the sprayer or spray generation systems in comparison with that of the reference system.

It is recognised that such evidence should comprise at least:

  1. results from a series of field tests (for complete sprayers and spray generation systems) or wind tunnel measurements (for spray generators) specifically designed to provide data for a LERAP-Low Drift Star Rating as part of the LERAP scheme;
  2. a collection of existing available information to support appropriate interpretation, extrapolation and interpolation such that the drift reduction requirements for a given LERAP-Low Drift Star Rating can be implied with a high level of confidence.

3.1 Drift reduction evidence from purposely conducted tests ('targeted data')

3.1.1 Complete boom spraying systems (sprayers)

Field tests must be conducted to an adequate defined protocol - see Annex 1 or the draft International Standard for the field measurement of spray drift. Results from such tests must report a minimum of:

  1. a profile of the measurable downwind drift deposits between 1 and 12 m from the end of the boom including measurements from samples collected at three separate distances between 2.0 and 6.0 m from the end of the boom using collectors positioned at the top of the target crop/grass/soil surface and designed to collect sedimenting spray drift;
  2. details of the drift sampling methods used and particularly a description of the collecting surfaces and tracer techniques;
  3. details of the conditions under which the measurements were made including a mean wind velocity measured at a height of 2.0 m above the ground, a mean air temperature at a height of 2.0 m above the ground and a physical description of the surface under the sprayer and over which the measurements of spray drift were made including the mean heights of vegetative cover;
  4. data as in (i) and (ii) above for both the candidate sprayer and a system representative of the reference system;
  5. evidence to validate the experimental approaches taken relating to:
    • the calibration of the machine prior to conducting the drift trial;
    • the calibration of any instrumentation used to monitor the sprayer and weather conditions during a drift trial;
    • the recovery and stability of the tracing system used.

Those submitting data packages to obtain LERAP-Low Drift Star Ratings are encouraged to submit as much relevant information as possible to enable an accurate definition of downwind drift profiles for both candidate and reference spraying systems. Data will be reviewed by comparing downwind drift deposition profiles for the candidate sprayer and the reference system with standardised reference drift profiles (see Figure 1.). Where the form of the downwind drift profile for the candidate sprayer differs from that of the reference system, a LERAP-Low Drift Star Rating will be awarded based on the highest level of drift in the 2.0 to 6.0 m region downwind of the end of the boom.

3.1.2 Nozzles or other spray generation systems (spray generators)

Protocols have been developed and published for sampling the airborne and sedimenting spray from both static and moving nozzles in wind tunnel conditions. Data can therefore be generated using such protocols with details of the measurement method being fully reported with the test results.

Results from such tests must report a minimum of:

  1. the measured downwind airborne spray deposits collected at three separate distances between 2.0 and 6.0 m from the edge of the spray pattern from the spray generator(s), using collectors positioned 0.5 m below the spray release height designed to sample sedimenting spray drift; or the measured downwind airborne spray deposits collected at three separate heights between 0 and 0.5 m below the spray release height at a set distance of 2 m or greater from the downwind edge of the spray pattern from the spray generator(s), using collectors designed to sample airborne spray;
  2. a description of the wind tunnel arrangement and sampling systems used including:
    • details of the spray generator mounting;
    • a description of the airflow conditions including the mean wind speed at spray generator height;
    • a description of the position and dimensions of the spray sampling system;
    • details of the tracing techniques used;
    • the floor conditions onto which the spray generator was spraying;
    • the sampling periods and methods of controlling spray generator output.
  3. data as in (i) and (ii) above for both the candidate spray generator system and a nozzle representative of the reference;
  4. evidence to validate the experimental procedures used including:
    • the calibration of control and monitoring equipment used to measure/control nozzle operating pressures, flow rates and wind tunnel air speeds;
    • the recovery and stability of the tracing system used.

Data will be reviewed by comparing downwind drift deposition profiles for the candidate and reference nozzles with standardised reference drift profiles. Where the form of the downwind drift profile for a candidate spray generator differs from that of the reference system, a LERAP-Low Drift Star Rating will be awarded based on the highest level of drift in the region 2.0 to 6.0 m downwind of the edge of the spray pattern.

3.2 Data packages based on results from existing field trials and wind tunnel experiments ('interpolated data')

It is recognised that for some sprayers and spray generators there may be a large body of drift performance data collected using protocols that differ from those referred to in 3.1 above which could be collated and interpolated to support a case for awarding a LERAP-Low Drift Star Rating. Such collation and interpolation must aim at generating a downwind spray drift deposition profile for the region 2.0 to 6.0 m downwind of a boom or nozzle spray pattern that can be compared with standardised profiles. Any such data package must demonstrate:

  1. that the data used was collected in a way such that the likely accuracy and reliability can be validated;
  2. that the methods of collation and interpolation are technically robust and reliable;
  3. that results can be compared with those for the reference sprayer/nozzle condition.

4. Data Submission Procedures

Data packages will be submitted to a laboratory accredited by HSE for the purposes of reviewing drift data. There are currently two laboratories accredited for such work, see Table 2 below, but other laboratories may apply to HSE for accreditation by demonstrating that they have sufficient expertise and resource to conduct the required assessments.

Accredited laboratories will also be able to work directly with organisations concerned with the design, manufacture and supply of nozzles and sprayers in generating data for inclusion within a data package for submission as a candidate for a LERAP-Low Drift Star Rating. However, where a laboratory has been directly involved in the generation of data relating to a candidate sprayer or spray generator within any package, it cannot be involved in the technical review of the same data package. Accredited laboratories may otherwise provide advice relating to the generation of data and subsequent assessment of spray drift in general support of the LERAP review process.

On completion of a review, the accredited laboratory will submit a report to the HSE who will consider the recommendation and award the LERAP-Low Drift Star Rating as appropriate. A formal letter will be sent by HSE to the organisation submitting the data package and a list of LERAP-Low Drift Star

Laboratories accredited for reviewing Low Drift Star Rating data packages (August 2014)

Eurofins Agroscience Services
Slade Lane, Wilson, Melbourne, Derbyshire, DE73 8AG.
tel: 01332 864800

Submission of data package
Dr Richard Glass Team Leader
Exposure Assessment

Technical consultancy
Dr Richard Glass
Team Leader
Exposure Assessment

Silsoe Spray Applications
Unit(NIAB), Building 42, Wrest Park, Silsoe, Bedford, MK45 4HP
tel: 01525 862995

Submission of data package
Dr M C Butler Ellis
Head of Silsoe Spray Applications Unit (NIAB)
tel: 01525 862995 ext. 104

Technical consultancy
Dr P C H Miller
tel: 01525 862995 ext. 100

Dr Miller (SSAU), Dr M C Butler Ellis (SSAU) or Dr Glass (EUROFINS) may be contacted to provide general advice relating to assessment of spray drift in support of the LERAP review process.

HSE will maintain a list of accredited laboratories on their web site. They will also conduct random checks on review evaluations conducted by accredited laboratories so as to ensure that a consistent approach is being used and that the methodologies used meet the required standards.

Any organisation submitting a data package for review and that is not satisfied with the outcome must first discuss the reasons for any dissatisfaction with the accredited laboratory to which the data was submitted. If the reasons for the dissatisfaction cannot be resolved then a joint meeting will be held involving those submitting the data package, representatives of the accredited laboratory and HSE.

Accredited laboratories will maintain records of data packages submitted for review for a period of at least ten years. These records will be available for inspection by representatives of HSE and by any third party subject to conditions of:

5. Indicative charging and timescales

The data reviewing exercise and the awarding of a LERAP-Low Drift Star Rating must be self-financing. A scale of indicative charges and response times is detailed below.

Charges and response times relating to the submission of a data package for LERAP-Low Drift Star Rating review

Data package (all types) with initial sort fee.         

Package assessed for completeness
Respond to submitter within 3 weeks.
£200 + VAT

Targeted data package accepted (sprayers / nozzles). Fee received.    

Data review conducted and results reported to HSE.
90% of applications to be processed within 3 months.
£2,800 + VAT

Interpolated data package accepted (sprayers/nozzles). Fee received

Data review conducted and results reported to HSE.
90% of applications to be processed within 3 months
£4,600 + VAT

Note: The charges relate to the consideration of the claim of any one level of LERAP-Low drift status that would cover all combinations of equipment and operational settings commonly supported by the same data package. Data packages must clearly state the level(s) of LERAP- Low Drift status claimed for any data therein.

HSE aims to process 90% of recommendations from accredited laboratories within one month of receipt.

Once a LERAP-Low Drift Star Rating has been awarded to a sprayer or spray generation system then it will remain in perpetuity as long as the equipment or operational specification did not change significantly. Notification of minor amendments to any equipment or operational specification already having LERAP-Low Drift status may be submitted to the accredited laboratory which evaluated the original data concerned, accompanied by a fee of £600 +VAT. That laboratory will consider those changes and confirm their being of minor significance, or otherwise (90% of such notifications being responded to within one month).

lerap accreditation

Further information

 
Updated 2021-08-23->