Sorry, I came into this a little late, and this may have already been suggested, but have you thought about adding salt? I can’t speak intelligently about what a salt solution will do to the presentation of theatrical blood, but adding salt (looks like you’ll need a lot of it) will significantly reduce the presence of infectious microbes. I used to do this with high school students with limited knowledge on sterile technique – they would culture obligatory halophiles on a range of high salt percentage LB plates, to reduce the likelihood of accidentally culturing something more menacing.

…good ole’ sodium chloride!

Just a thought

Good luck

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of ACTSNYC**At_Symbol_Here**CS.COM
Sent: Tuesday, December 18, 2012 5:08 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Update on theatrical blood bath

All,

I can't thank you all enough..  As you may remember we were discussing 1500 gallons of theatrical blood that was going to be pumped from six 275 gallon tanks into a wading pool on stage about every three days, exposed to air and feet, and back into the tanks again repeatedly for about 6 weeks.  

After reading through all of the answers, I decided there probably was no disinfectant system that would work due to the 10% loading of organic chemicals in the water and heat needed to be explored as an option.  The question now is the temperature.  Sterilization of water requires a rolling boil, but ain't no way those temps can be achieved under the conditions at the theater's holding tanks.  What about pasteurization temperatures?  Would they be enough? I've now even heard about strange thingies called hemophyllic actinomycetes that survive all kinds of heat.  But I'm not a bug person so I called on the CDC for help.

This is to let you all know I got the call yesterday and the CDC is on the case.  I talked at length to the person leading this charge and it was confirmed we were right:  there is no disinfectant system that will hold under these conditions without also being toxic to the waders and even to the breathers of air in the theater. 

I will let you know what happens.  Again:  many thanks.

Monona