Wednesday, June 3, 2009

Do "Natural" Sanitizers Work?

June 3, 2009

The Internet abounds with web sites that tout the use of "natural" sanitizers, such as vinegar and lemon juice. These products are inexpensive, non-toxic and very attractive to consumers who wish to avoid harsh chemicals and expensive cleansers. But they don't necessarily work.

Researchers in Ohio and Colorado recently compared the ability of chlorine bleach, hydrogen peroxide, vinegar (acetic acid), citric acid (the active agent in lemon juice) and baking soda to kill three common foodborne pathogens: Salmonella, E. coli O157:H7 and Listeria monocytogenes.

Ordinary household bleach was the clear winner, killing large populations of all three pathogens with a contact time of only one minute at room temperature. Hydrogen peroxide, used full strength out of the bottle (3% concentration) was second best. It took care of Salmonella and E. coli O157:H7, but was less effective than bleach against Listeria monocytogenes – even when the contact time was extended to 10 minutes.

Full-strength vinegar (5% acetic acid) killed Salmonella readily; vinegar had more difficulty, though, with Listeria monocytogenes and E. coli O157:H7. Citric acid (the "sanitizing" agent in lemon juice) was even worse, needing 10 minutes to knock off even Salmonella. And baking soda had no sanitizing effect at all.

The authors of the research report caution that their tests were carried out under very specific conditions. Real life tend to be more challenging than the lab experiments.

The bottom line? For effective and inexpensive sanitizing of kitchen counters, bathroom toilets and other areas where microbes lurk, nothing beats bleach.


  1. This work was done using supension testing. The use of suspension testing is not a scientifically valid means of generating statements in relation to sanitiser efficacy in relation to actual environmental or food contamination since attached orgasnisms (to either a food contact surface or a food) do not generally behave as those free in solution. i.e. they are less susceptible to sanitisers.

  2. Kaarin, thanks for your comment. That is what I meant about "real life", but I didn't want to get technical. Even bleach, the most effective of the sanitizers tested, will not perform as well in the presence of organic residues.


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