Best method for sterilizing plastics - (Aug/24/2013 )
I run a small business employing just 20 operatives. Each person wears a pair of reusable ear plug which is housed in a small soft plastic box. We throw the ear plugs and box out at the end of each day. This seems a waste of a plastic box to me and my question is, how can I safely sterilise the box using cold water. Cross contamination is a worry to me as the boxes would have no identifying marks to re associate the box to the original user. What would the best method be? Many thanks in advance for taking the time to help me. Koan
Rinsing in dilute bleach (10%) for 30 minutes would be very effective.
Depending on what the plastic can stand hydrogen peroxide or a hypochlorite (aka the bleach) or 70% ethanol where you can use cheap denatured alcohol.
Thank you for taking the time to reply. One further question if I may. How long would a solution of ethanol or bleach remain effective. When would be best to replace? Many thanks again
Ethanol will last as long as you keep it (obviously throw out the ethanol that you have used to sterilize the plastic), it isn't effective against many viruses, but works well for bacteria and yeasts.
Bleach will last a few days, it depends on the concentration and how much exposure to air it has.
koan616 on Sat Aug 24 15:38:56 2013 said:
I run a small business employing just 20 operatives. Each person wears a pair of reusable ear plug which is housed in a small soft plastic box. We throw the ear plugs and box out at the end of each day. This seems a waste of a plastic box to me and my question is, how can I safely sterilise the box using cold water. Cross contamination is a worry to me as the boxes would have no identifying marks to re associate the box to the original user. What would the best method be? Many thanks in advance for taking the time to help me. Koan
Why use ear plugs that you trow away each time?
Same with the boxes..
It would be cheaper (in the long run) to use (custom made) ear plugs that you can use for years....
Ever concidered this?
About the boxes itself: yeah can clean them indeed... and reuse them.
bob1 on Sat Aug 24 21:37:22 2013 said:
Ethanol will last as long as you keep it (obviously throw out the ethanol that you have used to sterilize the plastic), it isn't effective against many viruses, but works well for bacteria and yeasts.
Bleach will last a few days, it depends on the concentration and how much exposure to air it has.
Could you explain the exposure to the air?
What do you mean? You mean that the Cl ions will be released from the water (the bleach) and evaporate?
But for this to happen they have to be "released" from the bleach first, and set free in the water solution.. this does not happen that easly or does it? Does the contact with the air improve this perhaps?
Bleach decomposes into sodium chlorate and/or sodium chloride. Ammount of each byproduct is dependent on bleach quality, presence of metals,...
Check chemical compatibility tables to know if you can really use a given chemical, and be sure to rinse appropiately.
None of these will "sterilize". As said above, consider the effect on the material due to treatment and the remaining material inserted into the ear may well irritate some folks.
I'm with Pito - these are disposable and the labor cost savings versus someone(s) treating each will prob be minimal. There are cheaper PPE for ear protection than individually boxed units (not cotton but standard units).
Try this - http://www.grainger.com/Grainger/hearing-protection/safety/ecatalog/N-b2a?xi=xi
Thanks Phil, We are restricted by the nature of the business to use ear plugs for one day. We must keep them in a box if leaving the production area. We are not thinking of recycling the plug itself, just the box therefore the chance of irritation is small. Surely ethanol, as previously mentioned in an earlier reply, would sterilise the box. With the kind help from all who replied I now have a plan in place using 70% ethanol which will be delivered by our chemical supplier and the residue uplifted and disposed by them also. We will obviously monitor for any reaction. Thanks again everyone for your inputs