This from The Telegraph (UK) :
Failing drug test at work can lead to the sack
By Richard Alleyne
Workers were warned yesterday that they faced more random drug testing in the workplace after it was revealed one company sacked more than 10 per cent of employees it screened for cocaine and cannabis use.
Laing O'Rourke, the construction group, like many other firms, has introduced testing of its 23,000 workers on the grounds that its industry is "safety critical" and employees need clear heads.
Out of 1,500 checked this year, the company said 165 were sacked after traces of cannabis or cocaine were found in their blood.
While critics agreed that in cases of public safety such as construction and transport testing was necessary they feared many firms are introducing the schemes to keep a "Big Brother" eye on staff.
Gareth Crossman, director of policy at Liberty, the civil rights organisation, said: "What people do — whether legal or not — in their own time is not for their employer to dictate unless of course it directly impacts on work. They are not the police.
"The danger is that firms without a public safety criteria think that would be useful to weed out the workforce and increase productivity. That would be wrong."
Harry Shapiro, spokesman for DrugScope, the drug awareness charity, said: "The employer's job is to ensure profits and a safe environment for working. Neither of which is necessarily going to be impaired by someone smoking a joint at the weekend."
Nigel Stanley, spokesman for the TUC, said: "We think that employers should treat alcohol and drugs as a health related issue. If you suspect someone has a problem with them then rather than sack them you should send them to the company GP."
The use of screening for existing staff and new recruits is on the increase and seems to be following the American trend where up to 40 per cent of employers use random drug testing.
It is increasingly being used away from industries solely interested in safety and into other areas such as the financial services sector and the City.
The cost of illegal drug use to industry has been estimated at £800 million a year while absenteeism and loss of productivity through alcohol misuse is estimated to cost up to £6.4 billion.
About 16 per cent of UK businesses tested employees randomly in 2003 a figure which is said to be increasing.
Laing O'Rourke began testing in 2005. It employs a company called Medscreen to carry out the procedure which costs around £100 per employee.
Medscreen also tests for rail companies, the Jockey Club and most of the major oil and gas suppliers.
Laing O'Rourke claims to have seen a dramatic reduction in on-site accidents as a result of the clampdown. A spokesman said: "This is all part of making the site safer."
Out of the 165 sacked, 124 were for the alleged use of cannabis, 41 for the alleged use of cocaine and 21 allegedly had traces of both drugs in their system.