Hospital Disinfection of Lethal Viruses & Resistant Bacteria

We’re back with Indigo® Instruments to talk about disinfection in hospitals, and the requirements necessary to kill lethal viruses such as Ebola, and bacteria such as MRSA, VRE and C. difficile. Once again, we’re going to look at disinfecting with bleach, but this time, we’re using higher concentrations.

Higher Level Disinfection with Bleach

You’ve heard it on the news, and we’re certainly not the first to warn you of drug-resistant bacteria and life threatening viruses. By now, you’re well aware of MRSA (methicillin resistant Staphylococcus aureus), Clostridium difficile, VRE (vancomycin resistant Enterococcus), and of course, the Ebola virus.

Thankfully, the CDC has guidelines in place for disinfection in healthcare facilities, and the EPA has a list of registered products effective against these viruses and bacteria. As usual, chlorine bleach made the list.

As Indigo® Instruments has pointed out in their related blog article, relatively low concentrations of chlorine are usually effective in routine disinfection. This is not the case with drug-resistant microbes and lethal viruses.

Why? There are a number of factors involved, but here are the two most important:

  • Organic material, such as blood and feces, reduces the effectiveness of chlorine
  • Viruses in general can be very difficult to destroy

For drug-resistant organisms and surfaces that are highly soiled, the CDC recommends a 1:10 dilution of 5.25% – 6.15% bleach (5250ppm – 6150ppm sodium hypochlorite solution).

Indigo® Instruments FREE Resources

Extra High Level Chlorine test strip, chlorine test strip, extra high level chlorine, chlorine 0-10,000ppm test strip, hospital disinfection

 

As we mentioned in a previous post on Disinfecting Day Care Centers, Indigo® Instruments provides some excellent free resources on their website for calculating bleach concentrations. What could possibly be better than free?!

They also carry the Chlorine 0-10,000ppm test strip, which is our only chlorine test strip that measures levels above 5,000ppm.

Below is Indigo’s table showing how much bleach is needed to make up different concentrations of disinfectant based on an initial concentration of 5%. (Although most store-bought bleach sold in North America is rated at 5.25%, they have taken into account the fact that bleach loses strength over time.)

By visiting this link and clicking on the Specifications tab, you can view further instructions, along with the table below for making up various concentrations of bleach.

Amount of 5% Chlorine Bleach to Make Final Volume

2500 (ppm)ml Bleach 5000 (ppm)ml Bleach 10,000 (ppm)ml Bleach Volume (ml)Final
12.5 25 50 250ml
50 100 200 1000ml
200 400 800 4000ml
11.25 22.5 45 225ml (US cup)
47.5 95 190 950ml (US Quart)
190 380 760 3.8L (US Gal.)

 

Our previous article with Indigo® Instruments also mentioned their sanitizer dilution calculator, which can be used to prepare dilutions for chlorine. The screen shot below shows just how easy it can be.

 

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For access to these free resources and more information on chlorine test strips, please visit www.indigoinstruments.com. We recommend following Indigo® Instrument’s blog for other great topics, videos, and resources.