Breathalysers are widely available for retail sale here in the UK. However, as a specialist item they are not yet sold alongside other electrical goods on the high street. The best place to reasearch breathalyser choice remains the internet.
Our advice is to only buy from a specialist breathalyser dealer, with a long history of selling consumer breathalysers and professional breathalysers, and whom are offering UK based customer support and breathalyser service facilities. Make sure they are offering a good range of products from multiple breathalyser manufacturers. Check out the service or calibration requirements of the breathalyser you are considering, and ensure that the breathalyser supplier offers these services.
Digital hand held breathalysers need not be expensive. A good quality and accurate breathalyser costs around the same as a tank full of diesel