7 replies to this topic

[bknudsen]

Hello all,

My plant is seeing some pop ups of Listeria spp. during our monthly EM in high traffic areas. I've done some research & read that chlorine dioxide is supposed to be highly effective against Listeria so I purchased some Vital Oxide, but the container only recommends 9:1 dilution with no recommended ppm. I've searched every way I can think of to find a suitable ppm to keep the sanitizer at no rinse but haven't found much.

 

Has anyone found a recommended ppm for CD to use in their facility? Can regular chlorine test strips be used to determine what a 9:1 ratio is in ppm or do we need test strips specifically for CD? 

 

 

TIA

Edited by bknudsen, 26 September 2024 - 03:59 PM.

[kconf]

Why do you want to convert to ppm? Simply use 9 parts of water to 1 part of CD unless I am missing something. 

[bknudsen]

Why do you want to convert to ppm? Simply use 9 parts of water to 1 part of CD unless I am missing something. 

 

Mostly because I'm sure an auditor will bring this up, "how are we verifying our concentration"? We've had minor findings for the same thing in the past during SQF. Most sanitizers I have worked with have a ppm limit where they are no longer considered a "no rinse". 

[kconf]

Could you give more info on your CD? 

[jfrey123]

You can get by with documenting the 9:1 ratio:  a mixing log with employees measuring and documenting how much they used for each batch of sanitizer they created.  It's tedious and gets a little pushback from auditors, so expect them to ask a sanitation employee to show them how they would create a batch of sanitizer.

 

You could also validate test strips on your own.  Do an in-house write up on what ppm you achieve on a test strip with this brand of sanitizer when doing some bench tests.  I'd do like 5 separate proper mixings/testing to confirm repeatability, and I'd also intentionally under-dilute and over-dilute a few mixes to document the range the ppm would fluctuate if an employee didn't measure properly.  If you can get repeatable ppm results with your chosen test strips, I'd say add it to your chemical program records, add the test strip ppm instructions to your chemical use training documents and run with it.

[G M]

You need to know what concentration you've started with, which may or may not be directly given on the supplied material, but the equation for a dilution is pretty simple:

 

c₁*v₁=c₂*v₂

 

1mg/kg=1ppm

[Tony-C]

Hi bknudsen,

 

I would think in the range 100 - 200 ppm Chlorine Dioxide, however Sodium Hypochlorite might be a cheaper and more widely available disinfectant. Details and links below.

 

Chemical Disinfectants

Chlorine dioxide-based disinfectants are prepared fresh as required by mixing the two components (base solution [citric acid with preservatives and corrosion inhibitors] and the activator solution [sodium chlorite]). In vitro suspension tests showed that solutions containing about 140 ppm chlorine dioxide achieved a reduction factor exceeding 106 of S. aureus in 1 minute and of Bacillus atrophaeus spores in 2.5 minutes in the presence of 3 g/L bovine albumin.

 

PRODUCT INFORMATION SODIUM HYPOCHLORITE

Drain Disinfection. Sodium Hypochlorite is used as a drain disinfectant and is very effective against Listeria. However, heavy soiling in drains will neutralise the antimicrobial activity. It is recommended that drains are flushed with water before dosing with Sodium Hypochlorite at 50 ppm – 500 ppm. It is essential to check that acid is not being released to a common or interlocking drain.

 

Kind regards,

 

Tony

[bknudsen]

You need to know what concentration you've started with, which may or may not be directly given on the supplied material, but the equation for a dilution is pretty simple:

 

c₁*v₁=c₂*v₂

 

1mg/kg=1ppm

 

I worked through this yesterday & got 200 ppm on a 9:1 dilution. 

 

0.200% sodium dioxide --> 2000 ppm undiluted chemical (I used an online calculator for this)

 

2000ppm*1 oz. (to keep it simple) = C2*10oz.

C2 = 2000/10 = 200ppm