Is your vehicle windscreen washer a Legionella risk?

A few years ago some researches in the UK claimed “20% of all cases of Legionnaires’ disease are caused by an untreated vehicle windscreen washer”. This work was theoretical so apparenty not supported by actual cases.

It is certainly true it is possible to catch Legionnaires’ disease from a vehicle windscreen washer as the BBC reported in 2011:

However research carried out Frantisek Kozisek et al in 2010 in a report entitled “Case Study 2-Legionella in windscreen wash. Group Report Summer School on Quantitative Microbial Risk Assessment” concluded:

“In this case many assumptions were made, since there is a major lack of experimental data, however, the conclusion is still clear; it is better to use commercially screenwash rather than plain water, because the commercial screenwash also include a disinfectant so Legionella cannot grow in the reservoir of wiper fluid. Nevertheless, even so plain water is used as windscreen wiper fluid, the risk of a response according to the estimated dose is very low and therefore the chances of getting Legionnaires disease is minimal, even in the worst case scenario where you are a professional driver. Based on this it is concluded that the risk management should be minimal and cheap.”

So, whether the chances are “20% of all cases” or “minimal” there is still a risk of catching Legionnaires’ disease from plain water in your windscreen washer so the solution is to use windscreen wiper fluid as both reports recommended.

The point of this article is for all those company vehicles out there, does the company have a policy in place for only using windscreen wiper fluid, if not why not as it is a known hazard and so means if you do not do something about it you risk being guilty by default.

If you want to discuss this or any other Legionella, Pseudomonas or water treatment related issue then contact Collaton Consultancy Limited via: general@collatonconsultancy.com