Skip advert
Advertisement

Breathalyser test finds DIY kit results worryingly erratic

We find home breath test kits prone to inaccuracy. Our campaign calls on drivers not to drink at all when driving

Drivers could risk losing their licences plus further penalties by relying on personal breathalysers to ensure they are safe to drive after drinking.

A test by Auto Express, as part of our No Drink, No Doubt campaign, found that DIY kits can be inconsistent. We tested four, including a police-certified kit, using a gold standard calibration that mixes water and ethanol to create a sample on the cusp of the legal limit.

Advertisement - Article continues below

The police-certified Drager device gave a blood-alcohol reading of 0.076 per cent. The legal limit is 0.08 per cent, and if this had been at the roadside, it’s likely we’d have been asked to give an evidential sample.

• Autumn Statement 2014: what it means for motorists

The cheaper devices were tested in the same way, but all recorded us as over the limit. This may seem like they’re just being safe – which is great – but in reality they returned such varied and confusing results (right) that they left us unsure of their accuracy. 

Hunter Abbott, managing director for Now Group UK, which manufactures AlcoSense breathalysers, said: “You get what you pay for with these devices. It’s hard to have any confidence in them when you get such inconsistent results.”

• MPs call for measures to clamp down on school run anarchy

A spokesman for the Association of Chief Police Officers told us: “While personal breathalysers may offer an indication of a person’s alcohol level, they shouldn’t be relied upon and would not provide any defence in court if the reading was not accurate.”

DIY Breathalyser kit test: the results

Drager 6510 Tester

Gave a reading of just under the limit. All three tests we ran were within 0.003% of each other. Approved by the Home Office and police-certified.

Maplin gadget tester

Available in Tesco and electrical stores for just £4.99. The traffic light system said we were over, but did the same for a test without alcohol.

Digital display tester

Provided a higher reading on one test, then gave a different result without a sufficient amount of air in it. It did the same without us blowing into it, too.

Drive Safely Tester

Read 0.05% for one test – its highest rewethersult – although it sometimes went green to say we were fine. Unreliable when tested without alcohol, too.

Have you ever used a DIY breath tester to check if you're safe to drive? What do you think of our test results? Let us know in the comments section below...

Skip advert
Advertisement
Skip advert
Advertisement

Most Popular

Honda CR-V prices slashed by thousands, ZR-V gets cheaper too
2026 Honda CR-V - front cornering

Honda CR-V prices slashed by thousands, ZR-V gets cheaper too

Honda has revealed updated pricing for the CR-V and ZR-V models, with the latter getting a particularly chunky discount
News
2 Nov 2026
New Renault Megane to take on the Tesla Model Y with a radical makeover
Renault Megane - front quarter exclusive image Avarvarii

New Renault Megane to take on the Tesla Model Y with a radical makeover

Hi-tech ‘software-defined’ C-segment model heralds a new design direction for Renault as the firm works to achieve a 465-mile range
News
2 Nov 2026
New Fiat Topolino Dolcevita arrives as dinky electric convertible for £9,500
Fiat Topolino Dolcevita - front 3/4

New Fiat Topolino Dolcevita arrives as dinky electric convertible for £9,500

The cute electric quadricycle can now be ordered as a convertible for a small additional outlay
News
3 Nov 2026

Find a car with the experts