Two drugs increasingly under the spotlight in the UK are fentanyl and ketamine—both showing sharp year-on-year increases in workplace drug testing. This isn’t just reactive policy-making. It reflects real shifts in substance use patterns that employers can no longer ignore.

Fentanyl: From Foreign Crisis to UK Risk

Fentanyl is a synthetic opioid up to 100 times stronger than morphine. A highly pure dose as small as 2 milligrams—the size of a few grains of salt—can cause respiratory failure and death.

While some users may seek fentanyl knowingly, many others encounter it unknowingly, mixed into fake benzodiazepines like counterfeit Valium or street cocaine. In these cases, survival is often down to luck—a misjudged dose, or a poorly mixed pill could mean the difference between walking away or never waking up.

Although often framed as a US issue tied to the Mexican border, fentanyl is increasingly entering the UK conversation, both in real life and pop culture. TV shows like Mob Land (starring Tom Hardy) and ongoing media coverage are helping to bring awareness to this emerging threat.

But is this just narrative momentum, or is UK usage genuinely on the rise?

Fentanyl Testing Up 66.34% Year-on-Year

Whether the source of fentanyl exposure is deliberate or unintentional, testing demand is rising. Between April 2024 and April 2025, saw test volumes involving fentanyl climb from 15,600 to 25,950—a 66.34% increase.

Multi-drug workplace panels—those screening for fentanyl, opioids, and sedatives—were among the most in-demand. This is particularly relevant in sectors like construction, transport, manufacturing, and healthcare, where safety risks from impaired workers can have serious consequences.

Ketamine testing on the rise

Ketamine remains a popular recreational drug due to its low cost (around 25% that of cocaine) and new usage patterns, such as in “pink cocaine” blends (MDMA + ketamine, often without actual cocaine).

There was a 66.32% increase in ketamine-related workplace testing—from 37,035 to 61,600 tests between April 2024 and April 2025.*

Legal Sector Sees 40%+ Rise in Ketamine Testing

“We have seen several cases where ketamine use has been detected but not declared by the donor, despite other drug use being claimed, such as heroin and crack or cocaine. This may be due to ketamine being cut within other illicit drug preps. Clients are becoming more aware and are now requesting ketamine alongside cannabis and cocaine.”Mathew Wade, Lead Toxicologist, AttoLife

While legal testing often targets known or suspected drug use, it’s an important signal of growing awareness and concern around ketamine’s evolving role in substance misuse.

Under the Influence – and Underperforming

If employees are using fentanyl or ketamine, there are two key risks to consider:

1. They may not know what they’ve taken

An employee taking a counterfeit pill or contaminated street drug may have unknowingly ingested fentanyl—a substance so powerful that even 2 milligrams can be fatal. If they show up on Monday, they might be lucky to be alive.

But survival isn’t the only concern.

Any employee relying on sedatives, opioids or dissociatives—whether knowingly or not—can pose a serious risk to others, especially in roles involving machinery, vehicles, or patient care.

In one UK case, a lorry driver high on Valium and other sedatives crashed into a school bus, seriously injuring two children. In another, a nurse under the influence of tramadol caused a fatal car crash. These weren’t Friday nights—they were workdays. Sedated doesn’t always look intoxicated, but the risks are real.

2. They may not be on their “A game” by Monday

Let’s say an employee takes ketamine or a sedative-laced drug on Friday night. By Monday, they’re probably no longer under the influence in a clinical sense. But are they really firing on all cylinders?

• Oral fluid tests detect most recent drug use within 24–48 hours, depending on the substance.
• Urine tests cover a longer window—typically 2–4 days, and longer with frequent use.

So yes, weekend drug usage can still show up in a Monday test.

And even if the drug use doesn’t show up in testing, the after-effects can still linger—disrupted sleep, impaired focus, low energy, and dulled reflexes—all of which can impact performance and safety on the job.

That’s not someone you want on a building site, in a care home, or behind the wheel.

Implications for Employers

• Update your drug policies to reflect the realities of modern substance use—including synthetic opioids and ketamine.
• Consider 9-panel or extended test kits for both oral fluid and urine to capture emerging risks.
• Recognise the wider risks—not just intoxication, but sleep disruption, fatigue, and the cognitive hangover that follows heavy weekend use.

* According to AttoSure figures

www.attosure.co.uk