HCN Chemistry Question From Wiki.

[grant hutchison]

It's correct. Using bleach is unnecessarily hazardous. Also, the concentration of bleach for sale was cut from 18% to 5% a few years back.

Well, that change was to stop it being unnecessarily hazardous.
I'm just surprised because I saw (and smelt) hypochlorite bleach in use in a public place in the UK within the last couple of months. I'm guessing the restriction is a feature of your workplace, rather than some general rule.

Grant Hutchison

[Shaula]

Well, that change was to stop it being unnecessarily hazardous.
I'm just surprised because I saw (and smelt) hypochlorite bleach in use in a public place in the UK within the last couple of months. I'm guessing the restriction is a feature of your workplace, rather than some general rule.

In the UK household bleaches are defined as <10% hyochlorite, anything higher counts as an industrial bleach and must be treated as Corrosive (household stuff is just an irritant) which brings in extra safety rules, I believe. Most hospitals and schools have moved away from bleach based on Sodium Hypochlorite to a safer and equally effective disinfectant (Sodium Dichloroisocyanurate).

[grant hutchison]

In the UK household bleaches are defined as <10% hyochlorite, anything higher counts as an industrial bleach and must be treated as Corrosive (household stuff is just an irritant) which brings in extra safety rules, I believe.

Yes, that's what I was referring to - the change from >10% to <10% makes it considerably less hazardous, and reduces the number of restrictions on its use.

Grant Hutchison

[kzb]

Well, that change was to stop it being unnecessarily hazardous.
I'm just surprised because I saw (and smelt) hypochlorite bleach in use in a public place in the UK within the last couple of months. I'm guessing the restriction is a feature of your workplace, rather than some general rule.

Grant Hutchison

Yes it is still on sale in the UK and you will still find it in use. It is a restriction in our workplace, or possibly the cleaning contractor we use.

[kzb]

In the UK household bleaches are defined as <10% hyochlorite, anything higher counts as an industrial bleach and must be treated as Corrosive (household stuff is just an irritant) which brings in extra safety rules, I believe. Most hospitals and schools have moved away from bleach based on Sodium Hypochlorite to a safer and equally effective disinfectant (Sodium Dichloroisocyanurate).

It's a little disappointing that retail suppliers seem to have limited the concentration to 5%. From what you say they could still legally sell 9.9% concentration.

I think they also use the dichloroisocyanurate as a solid to chlorinate private swimming pools? It's not something I have to worry about though...

[BigDon]

How much do you need if you're just tackling amoebas and ciliates?