Air and Water Quality

Air and water quality means keeping the water, ice, steam, compressed air and room air that touch food or food surfaces clean and safe, so they don't become a source of contamination.

  • Food safety
  • Facility & equipment design

Under FDA's manufacturing rules, any water that touches food, food-contact surfaces or packaging must be safe and sanitary, and plumbing must block backflow and cross-connections between waste lines and clean water lines (21 CFR 117.37). For air, plants need ventilation that limits dust, odors and vapors such as steam, fans positioned so they don't push contaminants or allergens onto food, and construction that keeps drips and condensate off food and food surfaces (21 CFR 117.20). Compressed air or gas blown into food or used to clean food-contact surfaces must be treated so it doesn't add unlawful substances (21 CFR 117.40).

FDA's draft Listeria guidance describes contamination traced to a niche in a compressed-air filter near the point of use, and warns that standing water around drains can encourage Listeria. In a bakery, flour dust, steam from ovens and proofers, and condensation all need control. Water safety starts at the source: a business or cottage baker relying on a private well should test it, and CDC advises doing so at least once a year.

Key facts

Compressed-air point-of-use filter
Retains particles larger than 0.3 micron (FDA draft guidance)
Private well testing
At least once a year (CDC)
Plumbing rule
No backflow or cross-connection between waste and water lines
Compressed air touching food
Must be treated to avoid unlawful indirect additives

In a bakery or commercial kitchen

  • Dry compressed air at the source and filter it at the point of use; FDA suggests filters that retain particles above 0.3 micron
  • Change intake and compressed-air filters on schedule, or sooner if pressure readings or test results call for it
  • Install backflow protection on water connections so waste or sewage can never flow back into clean water lines
  • Exhaust oven and proofer steam and fix dripping ducts or pipes so condensate never lands on food
  • Place fans and air blowers so they don't carry flour dust or allergens toward exposed food or allergen-free lines

For home and cottage bakers

  • Test private well water at least once a year for total coliform bacteria, nitrates, total dissolved solids and pH
  • Retest a well after flooding, repairs, or any change in the water's taste, color or smell
  • Use clean drinking water for doughs, icings and rinsing tools, and keep ice in clean, covered containers

Related entries

Sources

Written by VanillaGoods in our own words from these sources. Last reviewed October 17, 2026.

  1. 21 CFR 117.37 Sanitary facilities and controls, Legal Information Institute, Cornell Law School
  2. 21 CFR 117.20 Plant and grounds, Legal Information Institute, Cornell Law School
  3. 21 CFR 117.40 Equipment and utensils, Legal Information Institute, Cornell Law School
  4. Control of Listeria monocytogenes in Ready-To-Eat Foods: Guidance for Industry (Draft, January 2017), U.S. Food and Drug Administration
  5. Guidelines for Testing Well Water, Centers for Disease Control and Prevention