Around one in 30 employees tested at work last year had taken narcotics, with the most prevalent drugs being cannabis, opiates and cocaine, figures from drug testing firm Concateno showed.
Drug use among employees was up 43 per cent on 2007’s figures.
The data comes from an analysis of 1.7 million tests carried out for 856 UK employers, including public transport firms, freight haulage and the emergency services.
Dr Claire George, Concateno’s laboratory director, said: “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 report also found the most likely age group to test positive for Class A drugs was the 25-to-34-year-olds as they were likely to have more access to disposable income.