Dr Georges Petitjean has warned that workplace drug testing has failed to keep pace with cannabis reform. Writing in Personnel Today, he said a laboratory can answer the wrong question perfectly.
An employee may provide a sample that tests positive for cannabis. The analysis can be technically sound and the chain of custody secure, yet the result may still not show impairment.
Petitjean raised the warning during September, which is Recovery Month. He argued that approaches to employee substance use have barely evolved.
His article explores how businesses can keep pace with changing medicine, legislation and the modern workforce. He says employers now face a practical difficulty in interpreting cannabis results.
The warning comes as medical cannabis use grows in the UK.
The legal landscape shifted in 2018, when certain cannabis-based products for medicinal use were moved into Schedule 2 of the Misuse of Drugs Regulations. This created a lawful route to prescription.
Recreational cannabis did not become legal. Yet cannabis can now sit on both sides of a workplace drug policy, as prescribed medicine and illicit drug.
The Care Quality Commission reported a 130% rise in private prescription items for unlicensed cannabis-based medicinal products between 2022-23 and 2023-24. Those are prescription items, not patients.
A prescription does not make interpretation simple. An employee may be using cannabis as prescribed, may also be using illicit cannabis, or both.
A routine positive result does not establish the source of every detected cannabinoid. Nor does it establish current impairment.
Urine can remain positive long after acute effects have passed. Oral fluid is generally more closely related to recent use.
Neither result, by itself, establishes that somebody is impaired at work. Presence and impairment are different things.
THC, the main compound responsible for the high, can impair attention, tracking and other abilities relevant to driving and safety. But there is no simple biological number that converts a THC concentration into a verdict of fit or impaired.
Research has found blood and oral-fluid THC concentrations to be relatively poor indicators of cannabis-induced impairment. Petitjean says this leaves employers with a practical difficulty.
He suggests greater emphasis on observable performance, conduct and occupational-health assessment in non-safety-critical roles. In safety-critical roles, he warns, the consequences of getting the judgment wrong can be catastrophic.
Event Details Shore House Canna, an adult-use dispensary in West Cape May, New Jersey, will host its 3rd Annual Fall…
Sabalenka Stops Play Over Cannabis Smell Top seed Aryna Sabalenka briefly halted her US Open third-round match against Kamilla Rakhimova…
CBDD Signs Definitive Agreement to Acquire BioCannabis CBD of Denver, Inc. (OTCID: CBDD) announced on September 15, 2026 that it…
Seventh Annual New Jersey Cannabis Convention Set NECANN brings the New Jersey Cannabis Convention back to the Atlantic City Convention…
The Violation Vermont Lt. Gov. John Rodgers plans to pay a reduced fine to settle a case involving an unlicensed…
Massachusetts Cannabis Market Reaches $10 Billion Ten years after voters legalized recreational marijuana in Massachusetts, the adult-use cannabis industry has…
