Supermarket Bleach

Northern Brewer · Post by **Northern Brewer** » Thu Mar 29, 2012 9:54 am

For whatever reason, regular thin bleach has disappeared from the supermarket shelves in recent months, which led me to considering the cheaper â€˜Smart Priceâ€™ or â€˜Betabuyâ€™ alternatives. All is not what it seemsâ€¦

Some indication of comparative strength can be gleaned from the recommended cold bleaching dilutions, which are as follows.

Morrisons Regular = Add 20ml to 5 litres
Morrisons Savers = Add 100ml to 5 litres
Asda Smart Price = Add 25ml to 5 litres (bottle says 50mls to 10 litres)

Morrisons Savers bleach is therefore one fifth on the strength of their regular bleach.

All of the above bleaches contain less than 5%. Back in 2007 Morrisons told Graham that their value bleach contained 1.8% chlorine, but I suspect this can no longer be the case.

If Morrisons Savers is one fifth of the strength of its regular bleach, then it must contain less than 1% chlorine. If so, then we probably need to use at least 25ml per litre to achieve 200ppm.

As for the others, 5ml per litre would hopefully be sufficient dilution for regular (assuming 4.5%) bleach and 6.25ml per litre for Asdaâ€™s Smart Price.

I have written to Morrisons and Asda to see if they can provide me with precise strengths. I have also hunted down a source of chlorine sanitising solution test strips (10-200ppm), to establish ideal dilutions for myself. http://d7750199.t122.iostudios.co.uk/Pr ... ProdID=248

I will report back in due course.

LeeH · Post by **LeeH** » Thu Mar 29, 2012 2:24 pm

I guess you use this instead of the regular youngs type powder?

Northern Brewer · Post by **Northern Brewer** » Thu Mar 29, 2012 3:19 pm

LeeH wrote:I guess you use this instead of the regular youngs type powder?

Yup. I gave up using proprietary stuff many many years ago. Two litres of regular (4.5%) thin bleach cost around 65p and will produce 450 litres of sanitiser. I've never had a problem with it either.

Northern Brewer · Post by **Northern Brewer** » Wed Apr 04, 2012 7:54 am

Edit: Since initially posting this I have run some additional tests and amended the results below accordingly. I have also included some photos, which don't truly reflect reality, but are nevertheless useful for comparison purposes.

Well, I've still not heard back from the supermarkets but the test strips have arrived. As a Yorkshire man, I was pleased to note that they could be cut in half; thereby doubling their number

The strips are designed to test available chlorine up to 200ppm. The instructions are to dip without agitation, then immediately compare against the colour chart. The chartâ€™s gradations range through 10ppm (pale violet), 50ppm, 100ppm, & 200ppm (dark purple). Beyond 200ppm the test strips don't really turn any darker at all.

The strips are difficult to use properly. The test time is given as one second, and beyond that time the indicator colour darkens towards the next colour in the scale, which could easily lead to false results.

It struck me that as well as comparing the test strips against the colour chart, it would also be informative to compare them against each other. On that basis, I set about determining how much I would need to dilute 1ml of each bleach to produce a 10ppm solution. The results were as followsâ€¦

Morrisons Regular Bleach needed 4.5 litres of water
Asda Smart Price Bleach needed 2.25 litres of water.
Morrisons Savers Bleach needed 1 litre of water.

This indicates that Morrisons Savers bleach is no longer 1.8% as they told Graham a few years ago. It is around half the strength of Asdaâ€™s Smart Price bleach and nearly one fifth of the strength of Morrisons regular thin bleach.

Anyway, to cut a long story short, this is how I now understand thingsâ€¦

Morrisons Regular Thin Bleach
Recommended cold bleaching dilution = 4ml per litre
Appears to be 4.5% or 45,000ppm
1ml per litre = 45ppm
Use 4.5 ml per litre for 200ppm sanitizer

Asda Smart Price Thin Bleach
Recommended cold bleaching dilution = 5ml per litre
Appears to be 2.25% or 22,500ppm
1ml per litre = 22.5ppm
Use 9ml per litre for 200ppm sanitizer

Morrisons M Savers Thin Bleach
Recommended cold bleaching dilution = 20ml per litre
Appears to be 1% or 10,000ppm
1 ml per litre = 10ppm
Use 20ml per litre for 200ppm sanitizer

Edit: Since initially posting this I have run some additional tests and amended the results above accordingly. I have also included some photos, which don't truly reflect reality, but are nevertheless useful for comparison purposes.

kebabman · Post by **kebabman** » Wed Apr 04, 2012 12:59 pm

Excellent research, any chance you could check out other supermarkets thin bleach please. I was behind someone with a big container of bleach in Lidl but i keep forgetting to investigate it for price and strength.

Northern Brewer · Post by **Northern Brewer** » Wed Apr 04, 2012 3:06 pm

kebabman wrote:Excellent research, any chance you could check out other supermarkets thin bleach please. I was behind someone with a big container of bleach in Lidl but i keep forgetting to investigate it for price and strength.

I would be delighted to, although I live in the wilds and there are no Lidl, Sainsburys, Waitrose, or Tesco supermarkets for miles, so it may take some time. I did recently check out Aldi, but only saw thick bleach for sale. The bleach shelves were once again bare at my nearest Asda this morning. Something seems to be going on and I question whether some European legislation is a factor (you can't buy bleach in some European countries).

It does however strike me that the recommended cold bleaching dilutions seem to be very similar to sanitizer strength. I think Morrisons have got theirs wrong, and I plan to raise this with them once they get back to me, as promised.

boingy · Post by **boingy** » Wed Apr 04, 2012 3:52 pm

Excellent! I love it when someone else does all the leg work!

I'm wondering if it's worth testing a know nstrength bleach like Domestos just to verify your test methods.

Oh, and do you now find yourself with a lifetimes stock of bleach???

Northern Brewer · Post by **Northern Brewer** » Wed Apr 04, 2012 4:47 pm

boingy wrote: I'm wondering if it's worth testing a know nstrength bleach like Domestos just to verify your test methods.

I don't think Domestos make a thin bleach, but I suppose the thick stuff would produce the same result. Whilst I have engaged is some speculation regarding the actual strengths, I went through a lot of trial and error to determine the correct dilutions to achieve 50ppm with each bleach. I am confident that my suggested sanitizing dilutions will achieve the 200ppm as measured by the test strips. Morrisons have indicated that they will get back to me, and I'm hoping that Asda will too at some point. I will report back here when they do.

boingy wrote: Oh, and do you now find yourself with a lifetimes stock of bleach???

Yes. particularly now that I will be diluting it far more than I have historically. Prior to running these tests I used to use the full strength stuff at 10ml per litre, and was mixing the cheaper stuff several times stronger. Now that I'm somewhat wiser, I'm hoping that I will see an end to white spots on my jeans

far9410 · Post by **far9410** » Wed Apr 04, 2012 7:38 pm

Wot about tescos??

Northern Brewer · Post by **Northern Brewer** » Thu Apr 05, 2012 8:06 am

far9410 wrote:Wot about tescos??

My nearest Tesco is 35 miles away. I should be passing it within the next few weeks, and will pick up a sample then.

Please note that I have amended some of my results and edited the post above accordingly. It now includes some comparative pictures.

Northern Brewer · Post by **Northern Brewer** » Tue Apr 10, 2012 10:56 am

Morrisons have now responded to my query regarding the chlorine content of their M Savers Bleach.

"This product typically has 1% w/w available chlorine, which equates to a sodium chloride level of 1.15%."

Post by **Aleman** » Tue Apr 10, 2012 4:01 pm

Northern Brewer wrote:Morrisons have now responded to my query regarding the chlorine content of their M Savers Bleach.

"This product typically has 1% w/w available chlorine, which equates to a sodium chloride level of 1.15%."

Sodium Chloride level or Sodium Hypochlorite? Sodium Chloride does not contribute to the chlorine level of the bleach which is provided by the hypochlorite! Sodium Chloride is used in bleaches as a thickening agent, where it provides Sodium and chloride Ions

Northern Brewer · Post by **Northern Brewer** » Tue Apr 10, 2012 5:14 pm

Aleman wrote:
Northern Brewer wrote:Sodium Chloride level or Sodium Hypochlorite?

Your guess is a good as mine. I dealt with customer services, who then dealt with technical services on my behalf, so things could have got lost in translation.

The 1% available chlorine does however confirm what my own tests showed.

Northern Brewer · Post by **Northern Brewer** » Fri Apr 13, 2012 11:28 am

Asda have now responded to my query, and tell me that their Smart Price Bleach contains 1.5% active chlorine.

This somewhat grates against my test results above. If I dissolve 1ml of that 1.5% bleach in 1.5 litres of water (to create a supposed 10ppm solution), the test strip turns a much darker shade of violet that looks nearer to 50ppm. Similarly, my 9ml per litre test would have only achieved 135ppm, but it clearly went beyond that.

However, I suppose we have to accept this bleach to be what Asda say it is, on which basis, 13.5ml per litre will be required to produce a 200ppm sanitizer.

kane · Post by **kane** » Sat Apr 14, 2012 9:34 am

Very interesting results!

Could the chlorine/chloride (?) in the water to start with, have any effect on the results?

Edit: I guess the result would be the same relative to them all, so ignore me!

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