Jump to content

  • Quick Navigation
Photo

What are the appropriate concentrations of Chlorine Dioxide for sanitizing?

Share this

  • You cannot start a new topic
  • Please log in to reply
14 replies to this topic

Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 28 November 2018 - 10:29 PM

Hello All,

 

My facility recently switched to Chlorine Dioxide from Sodium Hypochlorite and there was some confusion in regards to the appropriate concentrations for sanitizing. Our chemical distributor and I set our automated mixing unit up for potable water, which is regulated at 2-5 PPM, which did not fly with our QA Supervisor. Some miscommunication occurred in regards to the concentrations for our pasteurizers compared to our sanitize water drop hoses but the real issue was that this wasn't noticed until after we had installed the pump and began using chlorine dioxide!

 

From my understanding, potable water and 'sanitizing' water are regulated at different PPM's (2-5 PPM for potable/50-200 PPM for sanitizing).

 

Now, chlorine dioxide is supposedly much more efficient and powerful in terms of killing microbial organisms and requires a much lower PPM, but our QA Supervisor still has the sodium hypochlorite levels in mind of 150-200PPM. My fear is, with one day running our sanitize water at 2-5 PPM, are we running a risk of contamination within our product?

 

We've conducted some microbial swabs and sent them to labs for testing, but if someone has experience with chlorine dioxide, can you please help inform me? I'd really appreciate the peace of mind knowing what to expect.

 

Thank you!

-Gus



012117

    Grade - MIFSQN

  • IFSQN Member
  • 227 posts
  • 69 thanks
36
Excellent

  • Earth
    Earth
  • Gender:Male
  • Location:Philippines
  • Interests:Validation, basketball, chocolatier

Posted 28 November 2018 - 11:58 PM

Hi, Gus. Petty.

 

Instead of the microbial swab, I would be more interested in knowing what is the residual chlorine after I applied the same values.

 

For potable water, the recommendation by WHO is 0.2-0.5mg/L, residual chlorine. The country where you manufacture at may have different legislation that you want to check and comply with. Even if you apply the 2-5ppm and the water has high organic load and you end up with 0 ppm residual chlorine in your point of use (or test assuming you test is the farthest point), it will not be effective as disinfectant. In addition,  I would be asking my chemical provider if there are any factors that will further impact its effectivity such as if you are using it in the correct pH, correct temperature as it may breakdown in water immediately that may lessen its effectiveness, and contact time.

 

As for sanitizing equipment, industry somehow uses between 50-200 ppm depending on its application. This is preferred due to in some countries, it is been regulated that it will minimize the use of rinsing if you use that concentration. 

 

From literature, ClO2 breaks down into chlorine (and oxygen) 7-10% that hypochlorite, with that being said, 200ppm hypochlorite may increase further your chlorine disinfection. It would be better to follow supplier recommendation but give the proper context. 2-5ppm may be too low. Other factor as chlorine dioxide is usually generated as gas and may be lost under pressure or agitation and may impact higher chance of corrosion. Thus it would always be better to have help from supplier supported by studies and literature.

 

All the best.



Thanked by 1 Member:

Scampi

    Fellow

  • IFSQN Fellow
  • 5,444 posts
  • 1507 thanks
1,524
Excellent

  • Canada
    Canada
  • Gender:Not Telling

Posted 29 November 2018 - 02:11 PM

Are you receiving it as sodium chlorite?

 

this article may help and perhaps the QA supervisor is thinking they operate in the same way and they do not

 

 

https://www.birkocor...ide-its-a-gas
/

 

An issue that keeps coming up for chlorine dioxide is the safe amount to be in the air.......which is 0.1ppm, just to keep in mind

 

 

Whether you are using sodium hypochlorite or chlorine dioxide, there should be enough time left post sanitizing for the surface to drain and dry......no product should every touch ANY wet sanitizer

 

Essentially, allowed to drain and dry the surfaces should have negligible chemical residue (if using the correct dosage to begin with)


Please stop referring to me as Sir/sirs


Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 29 November 2018 - 03:57 PM

@012117  Thank you for the information. I will do some residual testing once we get the system back up and running. With all the confusion, we've shut down the pump and are sanitizing everything with premixed sprayers at 180 PPM. The pump that we had originally ordered, under the premise that our target was the potable water recommendation of 2-5 PPM, had a maximum capacity of 20 PPM. I was able to increase the output by magnifying the GPM sensor reading by 2.5X and increasing the Activator to Product ratio but this turned our water a green hue with complaints of a strong odor from employees. Ultimately, I should have done more homework about the chemical.

 

@Scampi  We are indeed receiving it as sodium chlorite and activating it with a 35% phosphoric acid. We mix the two chemicals by hand to get the correct PPM for our pasteurizers but our lab techs are also complaining of an incredibly strong smell. My manager and I had found that article the day that this all happened but only briefly scanned it for information. I appreciate the help though.

 

After all this information, I do have another question. When I increased the activator to product ratio, our water turned green and emitted a very strong smell. Also, when mixing the two chemicals by hand, the smell can be overwhelming. The question I have is; does increasing the activator contribute to the emission of gas, and if so, can I use a lower quantity of the activator and allow a longer mixing time to achieve the same PPM with fewer gas emissions?

 

Thank you again for the information.



Scampi

    Fellow

  • IFSQN Fellow
  • 5,444 posts
  • 1507 thanks
1,524
Excellent

  • Canada
    Canada
  • Gender:Not Telling

Posted 29 November 2018 - 04:25 PM

Can i ask why you think this is the best solution for you? Or why you switched

 

If it is for better microbial load reduction, PAA is much easier to use (pre mixed) and once it oxides your left with O2 and H20

 

You were not supplied with a dosatron to mix these for you? 

 

This ratio is to make water suitable for drinking, which I know is not the same but may help with the ratio's

Chlorine Dioxide via Sodium Chlorite and Phosphoric Acid Solutions

AquaMira uses a stabilized 2 part liquid system for chlorine dioxide.  Part A contains a 2% sodium chlorite solution and Part B contains 5% phosphoric acid solution.  Seven drops of each are mixed and added to a quart (liter) of water.  You will need wait several minutes for the two components to react prior to adding it to your water.
  


Please stop referring to me as Sir/sirs


Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 05 December 2018 - 08:15 PM

@Scampi   In all honesty, I didn't make the decision to switch. My manager made the decision for me and I'm doing everything I can to make it work.

 

We didn't get a dosatron for manual mixing, just a pump for injecting the chlorine dioxide in to our sanitize water hose system. Since the pump we ordered could only achieve 20 PPM, maximum, we had to order a whole new AANE system from Bio-Cide. It should be able to reach the 150-200 PPM requested from our QA Supervisor.

 

What is PAA, exactly?



MsMars

    Grade - PIFSQN

  • IFSQN Principal
  • 606 posts
  • 194 thanks
151
Excellent

  • United States
    United States
  • Gender:Female

Posted 05 December 2018 - 09:30 PM

PAA - peracetic acid.  Indeed it is very convenient and effective, but beware - IIRC, depending on your application and concentration rates it too can have a very strong smell. 



Abby7

    Grade - AIFSQN

  • IFSQN Associate
  • 31 posts
  • 3 thanks
4
Neutral

  • Canada
    Canada

Posted 05 December 2018 - 11:06 PM

Hi Gus,

I have now worked at 2 facilities who have decided to add Chlorine Dioxide to the sanitation procedures.

It was a few years ago at the first facility and I left before it was resolved - so the details below are a bit general.

 

We were also mandated to make this change and moved ahead without taking the time to investigate properly. 

We were also attempting to generate the chlorine dioxide by mixing 2 components and then diluted it automatically at point of use for both product washing & equipment sanitation purposes.

In both instances we were using <5 ppm ClO2.

We were required to have the generator located in a well ventilated area separated from the production area - no one was directly involved in the process.

 

This sanitation team used wash down hoses with 5 ppm of ClO2 - they did not like the change due to the strong odour and resulting headaches and sore throats.

 

As already stated above by @Scampi, the level in the air is regulated in Canada to 0.1 ppm max.

In the end - it was shut down by our Worker's Compensation Agency (EH&S) department as the ClO2 gas readily dissipates from the water and contaminated the air.

 

The 2nd facility installed a different system - generating concentrated ClO2 in a closed drum using a 'tea bag' of powdered sodium chlorite and citric acid which is then diluted using a dosatron - again at 5 ppm for both produce washing and sanitation purposes.

We took care to use only gentle water sprays dedicated to the sanitation rinse (produce and equipment) and did not have ClO2 in all the hoses used in the facility for cleaning/sanitation.

This installation has been accepted by the employees and considered successful as supported by the environmental monitoring and product micro data.

 

I am not familiar with CIP systems used in dairies - but the point of this reply - if your employees are complaining about an overwhelming odour; IMO - there is a problem and a legitimate concern.

 

I have also struggled trying to secure adequate research to support the concentration of ClO2 suggested by the supplier - hoping you and the QA Supervisor can come to a resolution on what will work for your employees and allow you to improve your food safety.



Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 06 December 2018 - 04:44 PM

@Abby7   That's my concern. If we still have the same issues with this new pump, we may have to cancel the entire project as well. 

 

The new pump/mixing unit we are trying pulls the chemical in with the water flow and mixes the two components inside a predetermined level of water. I've found that when mixing within water, it greatly reduces the order and respiratory issues we were having. The water sits on top and blocks any gas emissions.

 

That being said, going up to as high as 200 PPM I'm worried there isn't a real solution to the problem. We are planning on having that high of PPM travel through our water system and ultimately be applied through water hoses. I'm not entirely positive as to what our PSI is through our water system, but any agitation of solution seems to cause the same gas problems. Spraying the water out of a nozzle will surely cause some gas release.

 

If we can conduct some in house testing and prove that a lower PPM will be effective, I can lower it. Without that verification however, we will have to maintain a 150-200 PPM range.

 

Today will be the day we hook up the new pump and see what will happen. I'll update this post once we've had time to experience how this new system will work.

 

Thank you,

-Gus



Scampi

    Fellow

  • IFSQN Fellow
  • 5,444 posts
  • 1507 thanks
1,524
Excellent

  • Canada
    Canada
  • Gender:Not Telling

Posted 06 December 2018 - 04:51 PM

Yes, PAA does have a very strong odour...........but requires no mixing on site 

 

If the vendor sets up the dosatron for you and you get titrations daily/weekly you'll never have an issue with it

 

 

Good luck Gus


Please stop referring to me as Sir/sirs


Abby7

    Grade - AIFSQN

  • IFSQN Associate
  • 31 posts
  • 3 thanks
4
Neutral

  • Canada
    Canada

Posted 06 December 2018 - 05:10 PM

Hi Gus,

I wish you all the best today.

 

Chlorine dioxide is a better sanitizer (oxidizer) than sodium hypochlorite and isn't as corrosive, but getting the system set up correctly is a challenge.

Please take care when spraying from the hose nozzles, as you have already stated, it is in a gaseous form and readily dissipates as the water hits anything.

 

 

Again, all the best!



Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 12 December 2018 - 04:55 PM

Well, turns out we are going to scrap this project. 

 

Our chemical rep had an AANE system installed but because we were diluting it with water inside the AANE tank, the pump size needed to achieve 150 PPM is too large. That, coupled with the fact that we use multiple hoses at once, our PPM would drop significantly when a new hose line was in use.

 

We gave it our best shot, but after all these mishaps and the respiratory issues with employees, we've decided chlorine dioxide isn't the right choice for us.

 

I appreciate everyone's help and information.

 

-Gus



Abby7

    Grade - AIFSQN

  • IFSQN Associate
  • 31 posts
  • 3 thanks
4
Neutral

  • Canada
    Canada

Posted 12 December 2018 - 07:37 PM

Thanks for the update - this is unfortunate news; but given the 150 ppm concentration target - not a surprise.

 

Perhaps in time, others will add details of their experience using this sanitizer.

Regards,



Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 12 December 2018 - 08:21 PM

@Abby7   I hope so. There wasn't much information that I could find here in regards to chlorine dioxide. Maybe this thread can help others in similar situations in the future.



Gus.Petty

    Grade - Active

  • IFSQN Active
  • 8 posts
  • 0 thanks
0
Neutral

  • Earth
    Earth

Posted 25 December 2018 - 08:40 PM

Quick update:

 

We are considering going to a much larger system called a Titan 3. it an supposedly handle very high PPM counts while being capable of adjusting the free chlorine dioxide in the air.

 

One of my main concerns had been the safety and health of employees. The free chlorine is regulated at very low levels for the United States and I'm interested in seeing how this new equipment will be able to manipulate the free chlorine levels. It's an interesting concept.

 

This isn't a 'for sure' thing, but we've decided that we had insufficient information from the beginning. Now we are gathering all the information we can to be sure that we are well prepared.

 

If anyone has addition information or experience working with chlorine dioxide or the delivery systems in to water supplies, would you be willing to share? The company we are working with for this new system is called Bio-Cide.

 

Thank you all,

-Gus





Share this

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users