A local transport company is moving to protect its workers and the public by implementing a random drug testing policy, as the number of workplace drug tests surge nationwide.
Barrett and Taura Transport manager Mike Silcock said the Wanganui company drug tested potential employees before they were hired, however random workplace testing had yet to be implemented.
"We're just looking at that now."
None of the company's five workers had tested positive for drugs, and if they had, "they would no longer have a job with us", Mr Silcock said.
A comprehensive random testing regime would be in place in the next two months "for insurance reasons" and to protect staff and other road users.
New Zealand Drug Detection Agency (NZDDA) workplace testing stats show 7093 workplace drug tests were conducted in the Central region last year, of which 5 per cent were "non-negative". The figures showed cannabis continued to be the most frequent drug detected - showing up in 71 per cent of non-negative tests nationwide last year.
Opiates (including codeine), methamphetamine, amphetamine, cocaine and benzodiazepines were also detected.
Nationwide, the agency conducted 68,561 on-site drug screening tests in 2012, up 31 per cent from 2011.
The testing was predominantly carried out in safety-sensitive industries, including construction, forestry, freezing works, manufacturing, mining, oil and gas, transport and waste collection. Cannabis use was most common amongst forestry and construction workers, while methamphetamine was found predominantly in mining and oil and gas industries.
Regional trends showed traditional cannabis growing areas Northland, Bay of Plenty and the East Coast also had high cannabis usage - along with Wellington.
The other obvious regional trend was opiate (most likely codeine) abuse in the South Island.
NZDDA chief executive Chris Hilson said since late 2012, 15 per cent of all workplace drug screening was for synthetic cannabis, with the figure expected to rise.
Synthetic cannabinoids could be detectable in a person's system for up to 102 days, Mr Hilson said. This meant some employees still had the drugs in the systems on the job, many in safety-sensitive industries.
"It's not just the accidents that can happen that can affect the drug user, but the usage may result in injury to nearby colleagues, customers and suppliers, and in some cases the general public."
About 6.4 per cent of last year's tests were 'non-negative' - indicating the presence of a drug. Samples are then sent to a laboratory for confirmation.
The 2012 non-negative results were down slightly from 2011, when 7 per cent of on-site tests detected drug use.
New Zealand Council of Trade Unions (CTU) spokesman Jeff Sissons said the union condemned drug use if it put workers or the public at risk.
"A good drug testing policy may be fair enough in a safety-sensitive workplace, but a lot of the rise in drug testing we think is occurring in non safety-sensitive workplaces."
Health and safety requirements had to be weighed against invasion of privacy. Workers in office jobs in safety-sensitive industries should not be subject to random drug tests, as their role was not safety-sensitive, Mr Sissons said.
Last year 89 per cent of workers tested were men, and 11 per cent women.
While testing occurred pre-employment, random workplace testing was also common.
Rail and Maritime Transport Union health and safety spokeswoman Karen Fletcher said the urine testing process for female workers was "invasive and embarrassing".
The union favoured a saliva testing method, Ms Fletcher said.
Mr Hilson said although saliva testing was less invasive, it was also far less accurate.