[Cytometry] Clorox in a tablet: Summary

Julie GOLDEN Nelson jnelson at uga.edu
Mon Jul 19 09:29:29 EDT 2010

 Hi y'all,

I got a really nice response from you all. The folks in Europe, Australia and Canada use Presept or Virkon.  I couldn't find (on the world wide web) a source for Presept in the U.S. but did find Virkon.  I'm asking my Fisher rep now if they can get one or the other for me because I think I'll try one of these as they seem to be better even for the environment.  I also got lots of recs for using pool chlorine which is enticing, but when I checked those boxes at the local Target (granted, should probably go to a pool supply store), the amounts were listed in percents (as in 99% of some chemical which had chlorine in it) and I couldn't find any info on the box to help me figure how much chlorine, etc.  And I thought my biosafety people would be happier with something more "official". Below is the entire list. Thanks again for all your advice.  (As an aside, I did find something on this thread in the Purdue archives from about 2002 which said the same thing, so I apologize for the repeat.)

Julie Nelson
Flow Cytometry Core Facility
Center for Tropical and Emerging Global Disease
University of Georgia
jnelson at uga.edu

Summary Clorox in a tablet

We use the tablets that you buy from the supermarket to cold water-sterilise baby's bottles.  This was recommended to us by our BD engineer.  They contain a bleaching agent.  In the UK, these are called Milton tablets - I assume something similar must also be available in the USA.
Best wishes
Helen Barnby-Porritt

How about swimming pool chlorine, which comes in scoopable pellets and tablets? (disclaimer - these were available when I was a kid; haven't had a pool since)

Andrew Beernink
Flow Cytometry Field Systems Specialist
Beckman Coulter, Inc.
(858) 774-0425 mobile

You can buy more concentrated sodium hypochlorite solution from swimming
pool supply companies. This material is about 12.5% versus about 6% for
Clorox. You can also buy it in case lots which can further reduce the
number of shopping trips.

-Jim Weaver

For home use, I go to the dollar store and get Chlorine tablets, an 6
pack of 3/4 inch tablets, each of which makes a gallon of bleach.  These
might work depending on the size of your waste tank.

Roger Burger

or search for hypochlorite tablets just grazing the US sites.

Just remember to store the waste in a well ventilated area because of
highly toxic formaldehyde and chlorine adducts and you can neutralise
the chlorite with thiosulfate before it goes down the sink at least
that's what they tell me for hypochlorite but virkon is apparently less
toxic down the drain



We use Presept tablets.  The best thing about the solution is that it doesn't damage clothing if you splash it on yourself.  You can add the tablets directly to biohazard solutions, or use a premade solution for disinfecting surfaces, etc

They're made by Johnson and Johnson.  I've included some info from websites I found below.

SECTION  5              Disinfection Procedures

Biological materials should be inactivated before incineration either by autoclaving or by disinfection using hypochlorite as outlined below.

Presept  Tablets

Normal use (strong hypochlorite, 2500ppm)

1 x 5g Presept tablet in 1 litre water
1 x 2.5g Presept tablet in 500ml water
1x 0.5g Presept tablet in 100ml water

Once made the solutions can be used for up to 24 hours.

Heavy loads (10,000ppm)

4 x above concentrations for blood or visible amounts of tissue

Wiping surfaces (1000ppm)

1 x 2.5g tablet in 1 litre water
Source:  http://www.onc.ed.ac.uk/biologicalsafetyrules.htm

Presept Disinfection Tablets 5g Per 50
PRESEPT Disinfectant Products take hard surface disinfection beyond the confines of hypochlorites. A complete biocidal spectrum based on the unique action of NaDCC (sodium dichloroisocyanurate) ensures highly effective disinfection even in the presence of blood or other organic matter. And with long term stability in storage, full activity is guaranteed right up to the moment of use. In every department, PRESEPT Disinfectant Products provide a practical, convenient and rational approach to disinfection.

PRESEPT Effervescent Disinfectant Tablets

Making better solutions for disinfection

* Activity across the microbial spectrum, providing protection against many organisms including HIV, Hepatitis B, Herpes viruses and MRSA
* Better activity in the presence of organic matter than hypochlorites and may be used with confidence for all body fluid spillages
* Better biocidal activity than hypochlorites
* Stable and compact in storage, ensuring full biocidal activity up to the moment of use
* Safe, simple and accurate preparation
* Convenient, reliable and economical
* Compatible with certain detergents

PRESEPT Disinfectant Granules

PRESEPT Disinfectant Granules are effervescent disinfection granules containing the active ingredient soduim dichloroisocyanurate. They react with water in blood spillages to produce a rapid acting, wide spectrum disinfectant effective against vegetative bacteria, fungi, viruses and bacterial spores.


Wear disposable gloves. Apply granules liberally over the spillage to completely cover it. Do not breath dust. Leave for at least 2 minutes and remove using a disposable cloth.

Finally wipe surface with a damp disposable cloth and dispose of all waste for subsequent incineration.

Use biocides safely. Always read the label and product information before use.
Source:  http://www.medisave.co.uk/presept-disinfection-tablets-5g-per-50-p-6867.html

Gayle Thornbury
Flow Cytometry Department
Terry Fox Laboratory
675 West 10th Avenue, Rm 11-218
Vancouver, BC
V5Z 1L3
Ph:  604 675-8000 X7737(am) X7746 (pm)
email:  gthornbu at bccrc.ca<mailto:gthornbu at bccrc.ca>

I should have added, that I believe these tablets are very popular in Europe where they're not allowed to use sodium hypochlorite (environmental reasons).  The Presept tablets are buffered, and apparently much gentler on the environment than bleach (don't quote me, but I'm sure there's info out there about this).  It's too bad that more lab people don't know about them.

If you try them, or find out more good things about them, feel free to share the info with all purdue users!

        Thinking back (way back) to my lifeguarding days, we used a product called HTH which were tablets we tossed into the pool to chlorinate the water.  A product like this may do the trick; check out http://www.poolgeek.com/HTH-Pool-C805.aspx.


Wayne F. Green, Ph.D.
Flow Cytometry Core Lab
University of Utah
Salt Lake City, Utah 84132

I thought about this a long time ago and the only thing I could think of using was the long term
slow release chlorine tablets that they put in swimming pools.  They used to have these floating
things that looked like ducks with a canister underneath them that you put the tablets into.

Ron Hamelik

"Chlorine" is available for swimming pools in either granular or tablet form. The tablet form dissolves slowly, but the granular products sold as "shock" dissolve rapidly and might work. I bet you wouldn't need to add much to the waste tank.

Has anyone tried this?

You can use Virkon tablets (1 per 500ml) which also has a broader action spectrum then bleach.


Best regards,


Dr. Roy Bongaerts
Head Flow Cytometry Facility
Institute of Food Research (IFR)
Norwich Research Park, Colney
Norwich, NR4 7UA

This may sound strange but just may work.  Your need for a tablet sparked my mind.  How about a "Tiddy Bowl" tablet and just chunk it into the bottom of the tank?  Is there enough disinfectant in that? It would be real cheap and smell good.


Imperial College London and Prince Henry's Institute in Melbourne; both organisations moved to a Dupont product called Virkon. It has published efficacy results as a bactericidal, virucidal and fungicidal agent. The move to Virkon was motivated by convenience of tablet form, lower risk of exposure to end-users in terms of Occupational Health and Safety, and less of an environmental impact when compared hypochlorite-based disinfection. The down side is the expense when compared to Clorox.
In my old core facility I used to drop 1 or 2 tablets into the waste tank, leave overnight and empty the next morning down the sink.
Sach Jayasinghe, BSc(Hons) AFAIM ISAC Scholar | Cytometry Division Manager
Australasian Analytical Systems | M: +61 432 031 101| F: 1800 790 804

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