We are lucky enough to have four shared bikes at work, which are available for any employee to ride.

Due to New Zealand's compulsory helmet laws, we must provide some shared helmets. Some people don't like that idea, but it's not reasonable to ask them to provide their own if they don't have a bike.

What's a helmet-safe anti-cootie spray ? Isopropyl alcohol ? Or should we be providing disposable hairnets like go-kart tracks offer to their patrons? Disinfectants/deodorants like Dettol or Febreze?

Related - there is a bike rental scheme in my city (a bike-share system) and they also must provide helmets for riders. There is a periodic clean of the helmet when the bike is serviced, and they claim that happens 3 times a week Often these helmets stay in the bike's front basket instead of being worn, but they live outside

  • 1
    I have asked Nextbike and they won't say what they use to clean their shared helmets.
    – Criggie
    Commented Jun 20, 2017 at 7:30
  • 6
    Nextbike probably won't say because they don't use anything effective and know it.
    – Chris H
    Commented Jun 20, 2017 at 8:29
  • 2
    Is bowling shoe sanitizer a thing in NZ? Here in the US when you go to (indoor, ten-pin) bowling alleys they require you use special shoes on their lanes. Most people don't have their own, so the alleys have them for rental. After each use they spray them with an aerosol disinfectant, one which is specifically designed to disinfect the rental shoes (as opposed to a re-purposed generic or kitchen-cleaner disinfectant). I imagine it would also work on helmets.
    – R.M.
    Commented Jun 20, 2017 at 14:37
  • 1
    @R.M. that's an answer - not a comment
    – Criggie
    Commented Jun 20, 2017 at 20:59
  • 1
    If you have ever been to one of those indoor go-kart places (in NZ), you get a sort of papery elasticated liner to fit under the (shared) helmet. Presumably, these are only a few cents each so if you can source a box of them that might be a solution. They are fairly breathable so should be fine under a bike helmet.
    – Penguino
    Commented Jun 20, 2017 at 22:51

4 Answers 4


I'd be wary of using IPA because it may affect the glues used in the helmet, even if it doesn't attack the foam in any obvious way. And the manufacturer would probably advise against it (and many other disinfectants).

I doubt a hairnet would help, as forehead sweat is probably the biggest issue that will get complaints (I suspect people will react more to unpleasantness than any real risk of catching anything).

With regards to headlice, the CDC say

Spread by contact with clothing (such as hats, scarves, coats) or other personal items (such as combs, brushes, or towels) used by an infested person is uncommon.

but how uncommon is another matter (other authorities disagree, but anyway headlice die in a day or so off a person).

Ringworm (actually a fungal infection tinea capitis) may be more of a worry, but it's not common in adults to start with. Disinfectants can stop it spreading.

I don't know how maintenance of the bikes and helmets will be arranged, but I think passive or minimal-effort solutions are probably going to be best. Some ideas:

  • Just having plenty of helmets so they've got time to dry out thoroughly should help. It will cost more upfront but will extend the lives of the helmets so won't cost much more in the long run. Storing them where they'll dry quickly is a big step in stopping them smelling.

  • Cheap helmets with little or no absorbent padding over the foam part will be able to absorb less sweat, and shared helmets won't fit everyone very well anyway.

  • If you get better helmets with removable pads, someone can wash the pads -- but who? When? Where? (I have tried laundry bleach for destinking but find a good soak in homebrew sterilser most effective).

  • Regular users of these bikes (perhaps cyclists who for whatever reason don't bring their own bike to work) may be encouraged to use their own helmet -- perhaps a bulk-buy discount could be arranged. This would reduce the load on the shared helmets. I keep an old helmet under my desk, and would lend it with the bike I keep near work.

  • 1
    I do all the bike maintenance myself. Before I started, it simply wasn't done, and problems were fixed on a reactive basis. Cheap helmets aren't legal - they have to conform to a minimum quality specification.
    – Criggie
    Commented Jun 20, 2017 at 22:10
  • 2
    I'm guessing that you've got plenty of other work to do as well, and don't want this to take too long. I meant the cheapest legal helmets. Unless standards have changed (even if they haven't it may be different where you are) it's possible to get BS-compliant helmets with little or no absorbent material, which would seem to help.
    – Chris H
    Commented Jun 21, 2017 at 5:49

Have you also considered that Under NZ Heath and Safety laws, you have a responsibly to keep your workers safe - you have to ensure you are not endangering there health though poor hygiene. One thing you could do is ring Worksafe NZ and ask them for advice as to what you obligations are regards keeping helmets clean. I imagine its a similar problem to hazardous areas and hard hats for guests.

EBay sells hotel shower caps for around $5/100. Less than ideal from a sweating POV, but certainly provide the protection needed. Workers who don't want to use these could provide their own helmet, or use a washable liner (At this time of year a beanie would work nicely). A regular clean with soapy water would be all that is needed.

You cold also investigate reusable/washable liners - either one each for staff to use, or have a heap of them and launder them regularly. e.g Cycling Cap Bicycle Helmet Wear Headband Cap Quick Dry Bike Hat (Sorry for the shopping reference). See if you can get budget to make these a giveaway to anyone who wanted to use the bikes.

  • 2
    Hard hats are a different case in that they don't have any absorbent parts (or normally glues) -- both what they can transmit and suitable disinfection methods are liekly to be different. Certainly in the UK and Germany I haven't come across any between-users disinfection of hardhats even in places with extreme safety cultures. (I wouldn't know about daily procedures). +1. I'd provide my own helmet rather than wear something underneath, but that's no bad thing and the rare users need an option.
    – Chris H
    Commented Jun 20, 2017 at 9:08
  • 1
    Just found that the ones used by Nurses and such are called a "Bouffant Hat". A search for these brings up lots of results at around $5/100 (local suppliers).
    – mattnz
    Commented Jun 20, 2017 at 21:21

Considering the health concerns, between any number of skin-borne infectiions, diseases and just the general grossness of other people's sweat touching me... I don't think the bank of shared helmets is a good idea at all.

There are deodorizing and disinfectant products out there, I just did a quick google search for "bowling alley shoe rental spray" and came up with a lot of answers, which will probably go a long way towards getting those safe to use for multiple users. However, there just isn't any info at all about whether that stuff is safe on helmet foams or glue used to attach helmet foam to shell. I would worry about the risk of making the helmet less effective.

The best case scenario would be for each employee who uses them to have their own helmet.

  • 3
    Yeah - the Compulsory Helmet law is an additional barrier to riding. See how it rapidly gets "all too hard lets just not bother" to anyone who's not a motivated rider ?
    – Criggie
    Commented Jun 20, 2017 at 22:08

Dawn and a little bleach in warm water will kill just about everything, or some sanitizer like they use in meat production like a quaternary ammonia chloride. Alcohol based stuff is useless it doesn’t effect germs and viruses like the maker advertises.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.