Drugs and alcohol should be on a farm's hazard list and measures for mitigating their effects should be included in policies. Farmers must have a framework to deal with the risk, she said.
A standalone policy was needed, not just a line or paragraph in a general policy, and it needed to be linked to employment contracts. The consequences of the use of drugs or alcohol should be listed, including dismissal or rehabilitation.
Policies should also cover consequences for staff found cheating the testing system. Employers should set their own acceptable level for alcohol, she said. Many had zero tolerance.
Drug users were four times more likely to be involved in a workplace accident, were one-third less productive and were 10 times more likely to miss work, including being late for work and wanting to leave early.
Drugs and alcohol had also been linked to workplace fatalities. When introducing a drug and alcohol policy, education was needed for both management and staff.
An amnesty 30-day period could also be offered. Many farm houses were being tested for methamphetamine use and manufacture, Ms Gibbens said. Testing could establish levels in individual rooms.
Low-level rooms could often be fixed by cleaning and painting. The manufacture of the drug was accompanied by a chemical smell. There was also a tar-like substance, which had to be disposed of. Often it was found in gardens or in sealed containers.