Returnable Plastic Packaging Cleaning and Disinfection

Hi,

We have started a project on returnable packaging washing with a start up company who hopes to design a washing machine for us.

I am struggling to get my head around R&D washing protocol they proposed and any help would be appreciated.

During their R&D process they will carry out trials using laboratory glass washer. After the initial pre-wash the cleaning cycle proposed would include: alkaline wash with potassium hydroxide at 60deg C. for 15 minutes, followed by neutralising agent - citric acid at 60deg C. for 5 minutes and water rinse.

They consider disinfection to be achieved via combination of the thermal - 15 minutes at 60 deg C and chemical - acid rinse. The time/temperature ratio alone would be insufficient, so it leaves the disinfection process dependant on the chemical disinfection. Am I right to question the efficacy of the citric acid with the potassium hydroxide ions present in the solution and is there a ratio between the 2 chemicals which would make it work?

Secondly, the cleaning method that skips water rinse between the 2 chemical solutions is not what I am familiar with in my experience in food industry hygiene  but there are limits to my knowledge.  Is anyone familiar with that?

A) a lab glass washer is not a good simulation---trials should only be done on a model of the actual finished washer

B) were those chemicals chosen because they won't etch the plastic?

C) citric acid?? Doubtful that it will achieve the required results  https://www.ncceh.ca...ts_Aug_2014.pdf  (not even recommended for home use)

Alternative agent Advantages Disadvantages Primary active ingredient of at least one Health Canada registered disinfectant Conclusions Vinegar (acetic acid) Lemon juice (citric acid) Baking soda (sodium bicarbonate) • Natural product • Readily available and abundant • Low toxicity • Limited antimicrobial efficacy and narrow in spectrum • May damage the organoleptic properties of produce • May be corrosive or irritating • Has pungent and unwanted odours • Mixing acids with bleach can cause the production of chlorine gas • Acetic acid: No • Citric acid: Yes • Sodium bicarbonate: No • Applications are limited by poor antimicrobial efficacy and aesthetic considerations • Potential to be used in formulations of disinfectants • Unlikely to be used for commercial applications, but may have uses in domestic settings

There MUST be a rinse between the cleaning solution and sanitizer

I'd tell them to go back to the drawing board...........sounds to me like they just don't understand the standard requirements for food packaging

PLUS you've got the added hurdle of having zero idea what/levels of contamination you're dealing with

The idea is a noble one, but I would suggest you should be targeting sterilization on returnable containers, not just sanitization