These findings, part of the High Society: Drug Prevalence in the UK workplace research report, are derived from the results of over 1.6 million UK workplace drug tests over the last five years (2007-2011).
In the past five years, there has been a 43% increase in UK employees testing positive for drugs. Drug use was identified in 3.23% of the employees tested in 2011, rising from 2.26% in 2007.
There are 29.23 million people in employment in the UK. If the current 3.23% positivity rate from the report is extrapolated for the UK population, 940,000 British employees have drugs in their system whilst at work at any point in time.
The most prevalent drugs used by UK employees are cannabis, opiates (excluding heroin), and cocaine.
Claire George, laboratory director at Concateno, said: "The positivity rate of 3.23% reported in this study demonstrates that drug use in the workplace is an issue that employers should be aware of. These are conservative figures across the workplace, when you consider how many companies do not have a screening programme in place.
"Concateno has seen an increase in the number of businesses seeking assistance with drug and alcohol screening programmes, in order to identify, deter and reduce the risks associated with drug use in the workplace."
The data indicates 25-34 year-olds are more likely to test positive for Class A drugs including cocaine and amphetamines. This means that Class A drug use peaks a few years after entering the workplace rather than at the start of a career. Class A drugs can be expensive, and having more disposable income makes drugs like cocaine and amphetamines more affordable.
Following a peak in 2008, cocaine use dropped off with the lowest usage level by UK employees in 2009. However, usage has increased year on year since.
George added: "Drug screening programmes are a good way of identifying potential drug related issues in the workplace. The introduction of a balanced policy which includes an Employee Assistance Programme providing support and education, as well as drug testing, has been proven to reduce the level of substance misuse in the workplace over time. "
