Drug Testing For Railway Workers: Laws, Limits & Network Rail Rules

Author : Dr Mike Garside

Drug Testing For Railway Workers: A Guide For UK Rail Employers & Contractors

This article is for general educational purposes only and does not constitute legal or medical advice. Rail industry standards are reviewed and updated periodically, so always check the current version before making compliance decisions. If you have concerns about drug or alcohol use, please speak to a healthcare professional.

Drug and alcohol testing is part of everyday working life on Britain's railways. Train drivers, signallers, track maintenance teams and the contractors working alongside them all carry out tasks where a moment's lapse in concentration can put passengers, colleagues and the public at serious risk. On the railway, being unfit for work through drink or drugs isn't just a disciplinary matter – for safety-critical roles, it's a criminal offence.

This guide explains the law behind railway drug testing, the much stricter alcohol limits used across the rail industry, what changed in Network Rail's latest Drugs and Alcohol Standard, which drug groups railside tests cover, and where in-house screening kits fit alongside formal Sentinel testing.

Who counts as a safety-critical railway worker?

The drink and drug offences in the Transport and Works Act 1992 apply to people working on railways, tramways and other guided transport systems in roles that affect safety. These include:

• Drivers, guards, conductors and signallers, plus anyone else who can control or affect the movement of a train or other vehicle
• Maintenance workers who maintain, repair or alter the track, signals or the electricity supply to trains
• Staff who couple or uncouple vehicles, or check they're working properly before use
• Supervisors and look-outs for people working in a maintenance capacity

On top of this, the Railways and Other Guided Transport Systems (Safety) Regulations 2006, known as ROGS, require any organisation controlling safety-critical work to make sure the people carrying it out are both competent and fit to do so. The Office of Rail and Road (ORR) makes clear that these duties extend to all dutyholders working on a transport system, including track contractors.

What the law says about drink and drugs on the railway

Under section 27 of the Transport and Works Act, it's an offence for someone in one of these roles to work while unfit through drink or drugs. In other words, it's an offence to work while their ability to do the job properly is impaired. It's a separate offence to work after drinking so much alcohol that the level in their breath, blood or urine exceeds the prescribed limit, whether or not they feel affected.

Importantly, the operator of the transport system can also be prosecuted when one of these offences is committed, unless it can show it took all due diligence to prevent it. A structured, well-documented testing programme is one of the clearest ways for rail organisations to demonstrate that diligence.

The prescribed alcohol limits set by the Act are:

Sample	Prescribed limit under the Transport and Works Act 1992
Breath	35 micrograms (μg) of alcohol per 100ml
Blood	80 milligrams (mg) of alcohol per 100ml
Urine	107 milligrams (mg) of alcohol per 100ml

Rail industry alcohol limits are far stricter than the law

The legal limits above mirror the drink-drive limit in England and Wales. However, the rail industry has agreed that alcohol below those levels can still impair performance in safety-critical work. RSSB's Rail Industry Standard RIS-8070-TOM is the industry-agreed standard for testing safety-critical workers for drugs and alcohol, and it supports limits that are stricter than those in the Act.

Network Rail applies a limit of 29mg of alcohol per 100ml of blood, which is around a third of the legal figure. For breath testing, the cut-off used in Network Rail tests is 13μg per 100ml, so a reading of 14μg or above is treated as a fail.

Sample	Legal limit (Transport and Works Act 1992)	Network Rail limit
Breath	35μg per 100ml	13μg per 100ml
Blood	80mg per 100ml	29mg per 100ml

Network Rail's own awareness material notes that its limit can be reached with less than one and a half units of alcohol. A single pint of average-strength beer contains around two units. Alcohol from the night before can also still be in the body at the start of an early shift. These figures should never be used to work out how much you can drink before safety-critical work or driving.

A practical approach to in-house alcohol checks is to use single-use breath alcohol detectors for quick front-line screening, with a digital breathalyser for follow-up readings. Our employment alcohol screening pack includes 20 single-use detectors, an AL7000 digital breathalyser, a spare pre-calibrated sensor and 50 mouthpieces. Its 0.02% BAC screening threshold is equivalent to 20mg per 100ml of blood, which is below the Network Rail limit.

These are non-evidential screening devices. Where a reading may need to stand up to scrutiny, an evidential instrument such as a Draeger breathalyser is the better choice. You can compare options across our full range of workplace alcohol test kits and breathalysers.

Network Rail's Drugs and Alcohol Standard: what changed in 2025

Anyone working on Network Rail managed infrastructure will be familiar with NR/L2/OHS/00120, Network Rail's Drugs and Alcohol Standard. Issue 8 was published on 1 March 2025, with full compliance required from 7 June 2025. Key changes include:

• Non-negative random tests: where a point of care test (POCT) carried out as part of random testing gives a non-negative result, line managers must now complete a non-negative risk assessment.
• For-cause and post-incident forms: managers must complete a set form with the employee before deciding whether a for-cause or post-accident/incident test is needed.
• Tighter rules on medicines: prescribed and over-the-counter medicines should only be used where there's a legitimate medical reason. Staff must also seek advice from the chemist on call about any medicine with side effects that could affect safe working.
• Appeals: appeals against a positive result can now be submitted without a sponsor's backing, provided the evidence meets the standard's appeal criteria.
• Alternative samples: employees whose medical condition prevents them giving a urine sample can ask occupational health for guidance on an alternative testing method.
• PTS training: Network Rail employees no longer need to pass a drug and alcohol test in the three months before attending Personal Track Safety training.

Issue 8 built on the 2023 update, which made three main changes:

• It raised the minimum random testing rate for safety-critical workers, including contractors, from 5% to 20% a year.
• It allowed point of care tests to be used alongside laboratory tests.
• It added ketamine and tramadol to the required drug panel and removed propoxyphene.

You can read more in our earlier article on changes to the Network Rail drug test.

Which drugs are railway workers tested for?

Network Rail-aligned testing for safety-critical staff and contractors covers nine core drug groups. The table below shows how these map onto our two dedicated railside screening kits:

Drug group	12 panel railside urine cup	11 panel railside saliva kit
Cannabis (THC)	Yes	Yes
Cocaine	Yes	Yes
Opiates	Yes	Yes
Amphetamines	Yes	Yes
Methamphetamine	Yes	Yes
Benzodiazepines	Yes	Yes
Methadone	Yes (EDDP metabolite)	Yes
MDMA (ecstasy)	Yes	Yes
Tramadol	Yes	Yes
Ketamine	Yes	Yes
Alcohol	No (use a breathalyser)	Yes
Buprenorphine and pregabalin	Yes	No

Ketamine and tramadol are the groups most likely to be missing from older or more basic workplace drug test kits. Check any existing stock before using it for rail screening.

Urine or saliva? Choosing a railside screening kit

Urine testing remains the standard sample type for formal Network Rail testing, and it offers a longer detection window than saliva for most drugs. Our 12 panel railside urine cup has replaced the previous 11 panel railside cup. It covers every core drug group in the table above, plus buprenorphine and pregabalin. Each foil-wrapped, screw-lid cup also includes a three-pad adulteration strip and a temperature strip to help identify tampered samples.

Saliva testing is quick to supervise and difficult to adulterate. It is particularly good at picking up recent use, which makes it well suited to for-cause and post-incident checks. Our 11 panel railside saliva drug and alcohol test (ALLTEST DSD-8117) screens for the same core drug groups plus alcohol from a single swab, with results in around 10 minutes. You can also browse our wider range of workplace saliva drug test kits and combined drug and alcohol saliva tests.

As a general guide, saliva tests detect drug use from the previous few hours up to around three days. Urine tests typically detect most drugs for several days, and cannabis for considerably longer in regular users. Our drug test detection times guide has full details for each drug group.

Where in-house screening fits alongside Sentinel testing

It's important to be clear about what in-house kits can and can't do. Tests carried out to meet NR/L2/OHS/00120 must be performed impartially by an independent testing organisation. RISQS has confirmed that organisations can't carry out these compliance tests on people employed by the same legal entity. Results are then recorded on Network Rail's Sentinel system by approved providers.

That said, many rail employers and contractors run their own screening alongside formal testing to:

• Pre-screen new starters and agency workers before sending them for formal testing, reducing costly failures
• Carry out additional random drug testing under their own company policy
• Respond quickly to for-cause concerns or incidents on site
• Support return-to-work and ongoing monitoring arrangements

Screening, not confirmation: rapid drug and alcohol tests are screening tools only. Any non-negative result should be confirmed using an accredited laboratory confirmation test before any action is taken. Your policy should also set out what happens to the person's safety-critical duties while a result is being confirmed.

Building a railway drug and alcohol testing programme

Train operators, infrastructure contractors and small specialist firms in the rail supply chain all need a robust programme. It usually includes:

• A written drug and alcohol policy that sets out limits, testing triggers, consequences and support, in line with your clients' requirements
• Clear testing triggers, such as pre-employment, random, for-cause, post-incident and return-to-work testing
• A medicines declaration process, so staff know to check prescribed and over-the-counter medicines before a shift
• Trained collectors who follow the same procedure every time
• Accurate records, using a drug testing record and consent form for each test
• Access to support for anyone struggling with drug or alcohol use. Network Rail, for example, runs its own Drugs and Alcohol Support Programme for employees.

If your team is new to testing, our live online training webinar covers correct collection procedures, chain of custody, reading results and handling non-negative findings. Several people can attend each session. The webinar is included free with single orders over £500 on drug and alcohol testing products.

Railway drug testing FAQs

Is it illegal to work on the railway under the influence of drugs or alcohol?

Yes, for safety-critical roles. The Transport and Works Act 1992 makes it a criminal offence to work while unfit through drink or drugs, or while over the prescribed alcohol limit. The transport operator can also be held liable.

What is the alcohol limit for railway workers?

The legal limit is 35μg per 100ml of breath or 80mg per 100ml of blood, but industry limits are much lower. Network Rail applies a limit of 29mg per 100ml of blood, with a breath cut-off of 13μg per 100ml.

Can prescribed medication cause a problem on a rail drug test?

It can. Some medicines contain substances that rail tests screen for, such as codeine (an opiate), tramadol and benzodiazepines. Network Rail's standard expects staff to take medicines only for a legitimate medical reason and to seek advice on any that could affect safe working. In formal testing, confirmed positive results are reviewed by a Medical Review Officer.

Can contractors use their own test kits for Network Rail compliance?

No. Compliance tests under NR/L2/OHS/00120 must be carried out by an independent testing organisation. In-house kits are valuable for pre-screening and company policy testing, but they don't replace formal Sentinel testing.

How often are railway workers randomly tested?

It varies between employers. Since 2023, Network Rail has required at least 20% of safety-critical workers, including contractors, to be randomly tested each year, and individuals can be selected without notice.

Are saliva drug tests used in the rail industry?

Yes, particularly for in-house screening. Urine remains the standard sample for formal Network Rail testing. Occupational health can advise on alternative methods where a medical condition prevents someone from giving a urine sample.

For a quick overview of rail testing requirements, visit our drug testing for railway workers information page. If you're ordering in larger volumes for a contract workforce, our team can also help with bulk and trade pricing.