By Jessica Strauss
A major risk, according to the National Centre for Farmer Health (NCFH), is misreading the chemical filters fitted to tractor cabins to protect against chemical sprays, organic dust/gas and pollutants.
National Centre for Farmer Health, AgriSafe clinician Rachel Verschuren, said indicator beads in filters were not fully understood by some farmers.
Verschuren said some filters have an indicator cell that show farmers coloured beads in filters.
Others do not and need to be changed after a set number of service hours or a given period of time.
It is important that farmers and agricultural workers know which type they are working with.
Verschuren said the beads were made from activated alumina which is potassium permanganate impregnated.
“This means they change colour from purple to brown to cream as the carbon in the filter becomes saturated with toxic matter,” she said.
“When the beads turn cream they are due to be either reconditioned or replaced.
“But what we are discovering many farmers do not realise is after turning cream, the beads then return to a brownish/black colour if the tractor is not used for a while.
“Which means farmers can incorrectly assume the filter is still active. Some farmers are [also] not aware that after a period of time they should change their filters.”
The NCFH AgriSafe clinic has previously run occupational agricultural health assessments in the run-up to seeding. The founding centre is based at Western District Health Service, Hamilton.
A key focus is to assess the personal protective equipment used by farmers.
Verschuren said AgriSafe clinic staff had been concerned by confusion amongst farmers about the safety of their tractors at this critical time.
She said it was also possible for the coloured beads to slightly stain the plastic inside the indicator cell, making it difficult to correctly view colour.
“This highlights manufacturer recommendations for daily cleaning and checking of the chemical filter when in use in particular in dusty times,” she said.
Filters should be changed, or at least recharged as follows:
• After 400 hours of use (which means a usage log book must be kept)
• According to the inspection due date on your filter
• If the indicator beads have turned cream
• If there is any concern regarding the performance of the filter
“People using chemical filters in tractors should also be aware if the filter is moisture contaminated it will become inactive, and must be replaced,” Verschuren said.
“Protective clothing, gloves and an appropriate face mask must also be worn if you are reconditioning the filter yourself.
“To extend the filter’s life it should be removed and stored in a sealed, airtight bag when not in use. The original dust filter should then be reinstalled.”