Sprayer safety

Safe crop protection is what HARDI specializes in. Professional use of crop protection products today implies focus on:

  • Maximum biological effect and levels of control 
  • Minimum residue levels in food products 
  • Minimum risk of environmental contamination from drift and run-off
  • Maximum consideration for capacity, ease of use, safety and precision.
Filling the sprayer

Reduce risks when adding plant protection products

  • Add the plant protection products to the sprayer in the field so that you:
    - avoid using the same spot every time you handle concentrated chemicals ◦
    - benefit from an active soil breakdown of minor spills
    - avoid any risks from transporting a full tank of spray solution
  • Carry the plant protection products in safe lockers on the sprayer. It must be possible to collect any spillage that may occur from the containers.

Water filling

When filling the sprayer with water, avoid any risks of “over flow” or return to the water source. At the same time, special care must be taken that no spillage could end up in drains, wells, ditches or surface water unless the filling takes place on a special concrete area with efficient drainage to a safe container.

In practical life it is safest to fill the sprayer from a separate water tank – or if filling directly from a public or private water supply makes sure that the end of the filling hose is positioned minimum 10 cm above the sprayer filling hole.

The sprayer must not be left unattended whilst filling – to avoid overflow or other spillage.
Sprayer filling must not take place anywhere near wells or drills – please look up local guidance (In Denmark a distance of minimum 25 m is recommended by the “Landbrugets Rådgivningscenter (Tjekliste for håndtering af bekæmpelsesmidler på landbrugsbedrifter, 2000).
To minimise the impact on the environment due to smaller spillages or dripping always on the same spot, the water filling should preferably take place in the field. If filling water at the farm, an area covered with grass is preferred to that of stones or gravel. The safest alternative is to carry out the filling under a roof and with drainage to a separate tank.

Agrochemical filling
Filling of the plant protection products should also take place at varied places in the field. Transportation of the concentrated chemicals between farm and field must be safe and according to the local rules. In practice, it is recommended to transport the plant protection products in a locked box where it is possible to contain any spillage that may occur (like the lockers on CM+). A shovel and plastic sack may also be a wise precaution for they can be used to pick up any spillage of concentrated chemical if lost on the ground.
If filling plant protection products home on the farm it should take place on a concrete area where it is possible to pick up any spillage using special absorbent granules. If this is not possible then fill over a dedicated grass area that will help degrade any spillage. The sprayer pump should be off when transporting the sprayer from farm to field – to ensure the system is not under pressure.

When the agrochemical container is empty it must be rinsed either with the rinsing nozzle in the chemical filler or with 3 lots of clean water. In both cases it is important to move the container to make sure the rinsing is fully efficient. If using a ringing nozzle - the time used for rinsing a container - must be adjusted to the container size and an extra rinse with clean water afterwards will ensure that the container is as clean as it can be. The rinsing water must be added to the main spray solution. The rinsed containers are stored securely in a locked cupboard or compound.

Cleaning inside the sprayer

Label guidance
If a specific cleaning method is given on the label then this must be followed. Below you find more general guidance. Always remember to wear gloves, face shield and plastic apron/appropriate waterproofs when cleaning.

Residual volumes within the sprayer
The cleaning of the sprayer starts already when calibrating: if calibration is done correctly, there will be very little spray solution left in the tank after spraying.

Encourage in-field cleaning
The emphasis today is to encourage in-field cleaning using dedicated equipment on the sprayer.

In some instances, small residual volumes of spray solution have been drained from the machine and disposed using the services of an authorised company.

Dilute the remaining liquid and spray this out over an area which would comply with its approved use in a manner that avoids exceeding its maximum dose. Diluted 10 times with water and sprayed out over the just treated area or similar will often meet that requirement simply and effectively.

A dedicated rinsing tank mounted on the sprayer is the first important requirement for quick and easy field cleaning.

Infield rinsing with rinsing tank ( a daily routine)
The most efficient use of the water in the rinsing tank is achieved if the water is used in 2 to 4 lots; using half, one third or one fourth of the water for each rinsing. It is important that all valves are operated whilst rinsing so that trapped spray solution is removed from everywhere in the system.

If the sprayer is equipped with a rinsing nozzle this should be activated during each rinsing to achieve the most efficient cleaning of the internal spray tank. It is important that the sprayer is emptied as much as possible after each rinsing to ensure maximum dilution with each new introduction of rinsing water. The rinsing water is sprayed in an area of the crop just treated. Ensure that the maximum approved dose for that product is not exceeded.

Rinsing without rinsing tank (daily !)
To minimise the amount of rinsing water that has to be used and then disposed, the tank is flushed internally using the equivalent of 10% of the tank size. This is repeated twice. A high pressure cleaner is a useful help. After each rinsing stage, the rinsing water is sprayed over an area of low environmentally-valued vegetation that will not be damaged near the farm but, if possible, the just treated crop or similar is preferred. Before applying the rinsing water over the crop, all valves must be activated for a complete rinse. Do remember that whichever way you dispose of plant protection products, the procedure used must comply with your local rules and regulations. In partcicular, be aware that no rinsing water ends up in ditches, drains or sewages.

An absolute cleaning of the sprayer following one type of crop use ready for another. To be able to confidently treat crops that are very sensitive to the agrochemical that has just been used in an earlier application, it may be necessary to chemically breakdown the smallest traces of the active that are stuck to the structures of the sprayer. If a method is written on the agrochemical label - this must be followed!

Otherwise there are 2 possibilities:
Cleaning without rinsing nozzle: Fill the spray tank with water and an approved cleaning agent like ammonia, bleach or a product marketed for sprayer cleaning. Turn on the pump and let the solution circulate through the whole system for 15 minutes. Do operate all valves – on sprayers with selfcleaning filter: increase the pressure until the safety valve is activated, then reduce the pressure again. To ensure that the tubes and hoses on the boom are also cleaned remember to let the nozzles spray for a while during the process onto grassland or the just treated crop. Leave the sprayer for a couple of hours to ensure that any residues of chemicals are de-activated. This cleaning solution may be sprayed over the just treated area or grassland.

Dismantle and remove all filters and nozzles and place them in a container of the same cleaning solution as used in the spray tank. After a while they are given a final clean with a brush and rinsed with clean water and fitted back on the sprayer again. Finally the whole sprayer is rinsed with clean water that is also sprayed over the just treated crop or grassland – somewhere with vegetation where it does no harm.

Cleaning with a rinsing nozzle: Fill the tank to 1/10 of the capacity with water and cleaning agent. Activate the rinsing nozzle and let the liquid circulate in the whole liquid system for 15 minutes whilst operating all handles and valves. Then follow the procedure as described for “Cleaning without rinsing nozzle”

Protecting the environment when spraying

A wind streamer mounted in front of the tractor will help to show the operator which way the wind is blowing and its likely force. It will help you to know when to be extra cautious and maybe react with coarser nozzles.

Plan ahead for any emergency and try to anticipate problems. For example, if the wind speed is currently acceptable but is forecasted to rise then consider spraying the downwind swath edges first.

Never try and do maintenance with spray liquid in the tank and in the field.

Escaped spray liquid will soon apply a huge excessive dose that can run-off and contaminate water within the soil or adjacent to it – or cause a sterile area of soil to be formed that will remain for many years.

Avoid over spraying for it is wasteful and puts your crops at risk as well as posing a hazard. Use the boom section valves for areas, which are less wide than the swath. If treating an “angled” field it is worth the effort to turn on off the boom sections as the boom passes over the already sprayed area close to the headland. HARDI TRIPLETS have an ‘off’ position for you to use if you need to control swath widths by 0.5 m sections; in particular, when next to water ways.

External cleaning

An area covered with low value, unused grass may be an appropriate “filter” for distribution of rinsing water from the sprayer and an appropiate place to clean the outside of the sprayer and tractor. The grass hinders the agrochemical solution from moving away and encourages it to be chemically bonded to soil particles and subsequent degradation. Therefore it is advisable to have such an area - moved every year - nearby the farm.

Another possibility
Another possibility for most sprayers involves having supplied or fitted, special equipment for external cleaning of the sprayer in the field. This - to be preferred - procedure is still being developed but some of the clean water in the dedicated rinsing tank has to be reserved for this extra purpose.

Hoses with a high pressure supply are being used to rinse those areas of the machine that get the greatest level of contamination; the rear of the tank, the booms and wheels. The frequency at which external cleaning takes place will depend on factors such as spray quality and wind direction as well as exposure time and temperature. Todays evidence suggests that infield cleaning is likely to be a routine that should be done at the end of every spraying day. It is an activity that is of great importance for both personal and environmental safety when storing the sprayer.