By John Carillo, FSG Instructor
History
Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele. He combined hydrochloric acid with manganese dioxide to produce a greenish-yellow mix. In the 18th century, French fabric industries mixed chlorine with alkaline water to produce “bleach.” In 1810, Sir Humphry Davy confirmed the gas and named it Chlorine, based on the Greek word “Chloros,” meaning greenish-yellow.
In 1897, a bleach solution was added to a water main in the United Kingdom town of Kent to disinfect the drinking water. This chlorination process followed an outbreak of typhoid. This treatment helped reduce waterborne diseases like cholera, dysentery, and typhoid fever.
Chlorination was applied to the major U.S. city of Jersey City, New Jersey in 1908, ushering in the era of potable water for the ever-increasing U.S. population at the turn of the century.
The Environmental Protection Agency registered Chlorine Dioxide in liquid form as a disinfectant and sanitizer in 1967. Applications could be used in food processing, washing fruits and vegetables, and sanitizing water.
Foodservice Uses
Chlorine is a highly effective disinfectant and sanitizer widely used in food processing and commercial kitchens. When used correctly, it effectively eliminates pathogens and spores. The proper dilution of this chemical with water ensures its forcefulness. Like all solutions, usage will break down its properties. Therefore, testing the solution is critical at the beginning of a task and during a process. The solution must be discarded when the parts per million (ppm) fall below the recommended sanitizing or disinfectant levels. Solution-specific test strips must be available for employees, and attention must be paid to the integrity of the test strips. The vial of precut strips or a tape dispenser container should contain an expiration date and manufacture/Lot number. A website scrape highlighted these test strips cost between $3 to $15 depending on the count.
Any chlorine bleach used must be food-grade. Some commercially available household chlorine bleaches contain fragrances, thickeners, and/or other additives not approved for food use.
Chlorine is a cost-effective sanitizer compared to quaternary ammonium compounds (Quats). A gallon of chlorine at Target (Clorox brand) costs $5.79/*3.7 Qts pre-tax, Walmart $6.25*, and CUB Foods $9.49*.
In a general website scraping (pre-tax & shipping), food-grade quats ranged from $27.79/gallon mixed (QE Supply) to $74/gallon concentrate (Ecolab) and $54.75/gallon concentrate (Betco Quat).
Safety note: Food handlers must be trained to use all chemicals. This includes familiarity with the Safety Data Sheet, appropriate surface and application usage, proper dilution ratios, strength testing, recommended Personal Protective Equipment (PPE), proper ventilation, and first aid.
The two figures below are part of the FoodSafetyGuy Chapter 10 CFPM presentation deck. These slides, incorporated with the rest of this chapter, give students a good overview of proper cleaning and sanitizing.
Figure 1
Figure 2
Storage
Over time, chemicals lose their effectiveness even when stored correctly, i.e., in a dry location away from heat or sunlight.
Bleach has a one-year shelf life when stored properly whether open or unopened. This is based on the production code stamped on each bottle. However, always consult with your local regulatory authority on your compliance thresholds.
The Clorox website has an easy way to determine the production code, which is based on the Julian calendar (numbered days out of 365 total days in a year). If the production code on the bottle states, for example, A822234411: 31CA3, A8 is the plant location, 22 is the year of production, and 234 is the day of production or August 22nd (non-leap year).
References
Wikipedia. “Chlorine.” Retrieved July 10, 2024 from http://www.en.wikipedia.org/wiki/chlorine
Center for Disease Control (2012). “History of Drinking Water Treatment.” Retrieved July 10, 2024 from http://www.cdc.gov/healthywater/drinking/history.html
Boulder Sterilization. “The Long and Storied History of Chlorine Dioxide.” Retrieved July 10, 2024 from http://www.bouldersterilization.com/chlorine-dioxide-history/
Melissa Vaccaro (2016). “Know Your Sanitizer.” Nutrition & Foodservice Edge. Retrieved July 10, 2024 from http://www.anfponline.org/docs/default-docs/docs/fpc052016.pdf
William McGlynn (2016). “Guidelines for the Use of Chlorine Bleach as a Sanitizer in Food Processing Operations.” Oklahoma State University. Retrieved July 12, 2024, from http://www.okstate.edu/fact-sheets/guidelines-for-the-use-of=chlorine-bleach-as-a-sanitizer-in-food-processing-operations.html
Mary Gagliardi. “How to Tell When a Bleach Bottle Was Made.” Retrieved July 15, 2024 from http://www.Clorox.com/learn/how-to-tell-when-bleach-bottle-was-made/
Clean-up and Disinfection for Norovirus (“Stomach Bug”), disinfect-for-health.org. Updated March, 2015
OSHA FactSheet: Noroviruses, www.OSHA.gov. May, 2008
SafeMark Best Practices: Norovirus Information Guide, Ecolab and Food Marketing Institute. July 2010.