Sanitizer Concentration Calculator (PPM)

Georgia Food Code §511-6-1 demands chlorine between 50 – 100 ppm, quaternary ammonium (“quat”) at the manufacturer’s 200 – 400 ppm, and iodine 12.5 – 25 ppm. Accurate dilution protects guests and keeps inspections painless. This calculator shows exactly how much stock solution to add—no guesswork, no critical violations, just safe sanitation.

Calculations assume room-temperature water (68 °F / 20 °C). Retest if water exceeds 120 °F or is visibly soiled.

Choosing the Right Sanitizer for the Job

All sanitizers aim to knock down pathogens, yet each chemistry excels under different kitchen conditions. Chlorine bleach is the old standby—cheap, easy to source and lethal to most microbes in seconds. It shines in three-compartment sinks where dishes are fully submerged and rinsed afterwards. Because chlorine works fast but loses strength quickly, you’ll need to change sink water every four hours or when PPM drops below 50. Bleach is also your go-to when organic soils are low. Heavy food residue burns through available chlorine; pre-scrub plates before the sanitizing dip to avoid wasted chemicals.

Quaternary ammonium compounds (“quats”) are water-clear, low-odour and less corrosive to metals, making them ideal for wiping cloth buckets, prep tables and front-of-house spray bottles. Manufacturers blend surfactants into quat concentrates, so the solution clings to surfaces and keeps killing as it dries—great for high-touch handles. Most labels call for 200–400 ppm; Georgia inspectors default to 200 ppm if the bottle is illegible, so keep a printed spec sheet near the dispenser.

Iodine solutions occupy a middle ground. At 12.5–25 ppm they are gentler on skin than bleach, stain plastic light-amber for easy visual checks, and maintain activity in mildly acidic water. Iodine is common in sushi bars and bars where glassware requires a no-rinse final dip. The trade-off? Iodine costs more per gallon and loses strength if water temperature exceeds 120 °F. Whatever product you choose, the rule of thumb is simple: match chemistry to surface, soil level and turnover speed, then verify with fresh test strips.

How the Math Works

Sanitizer strength is measured in parts per million (ppm). Household bleach at 5 % contains roughly 50,000 ppm of available chlorine. To dilute, apply the equation:

Required volume of stock (mL) = (Target PPM × Solution Volume L) ÷ (Stock PPM ÷ 1000)

Example ① — Chlorine: You need 100 ppm in a 3-compartment sink holding 10 L. Bleach 5 % is 50,000 ppm.
Required mL = 100 × 10 ÷ (50,000 ÷ 1000) = 20 mL (≈ 0.7 fl oz).

Example ② — Quat: Produce 300 ppm in 5 gal (18.9 L) using 10 % concentrate (100,000 ppm).
Required mL = 300 × 18.9 ÷ (100,000 ÷ 1000) ≈ 56.7 mL (≈ 1.9 fl oz).

Worked Example:
Target: 50 ppm chlorine, Volume: 1 gal (3.785 L), Stock: 5 % bleach.
50 × 3.785 ÷ 50 = 3.8 mL → about 0.8 tsp or 0.13 fl oz.
Chef measuring bleach to prepare sanitizer solution in a commercial kitchen

Quick-Reference Dilution Chart (5 % Bleach)

Volume 50 ppm 100 ppm 200 ppm 300 ppm
1 gal (3.8 L) 3.8 mL / 0.13 fl oz 7.6 mL / 0.26 fl oz 15.1 mL / 0.51 fl oz 22.7 mL / 0.77 fl oz
5 gal (18.9 L) 18.9 mL / 0.64 fl oz 37.9 mL / 1.28 fl oz 75.7 mL / 2.56 fl oz 113.6 mL / 3.84 fl oz
10 L 10 mL / 0.34 fl oz 20 mL / 0.68 fl oz 40 mL / 1.35 fl oz 60 mL / 2.03 fl oz
20 L 20 mL / 0.68 fl oz 40 mL / 1.35 fl oz 80 mL / 2.71 fl oz 120 mL / 4.06 fl oz

Sanitizer Calculator FAQ

Inspectors look for 50 - 100 ppm of free chlorine when testing a 3-compartment sink. Falling below 50 ppm means inadequate microbial kill, while levels over 100 ppm risk chemical residues and corrosion. Always test after refilling or every four hours, whichever comes first.

Georgia follows the FDA 4-hour rule: sanitizer solutions in wipe buckets must be changed at least every four hours, or sooner if the solution becomes visibly dirty or drops below the required PPM. Logging each test helps prove compliance during inspections.

The Department does not endorse specific brands, but the strip must match the sanitizer: chlorine strips for bleach, QT-10 or QT-40 for quats, and iodine strips for iodophors. Keep strips in a cool, dry place and replace them before their printed expiry date.

Bleach degrades rapidly in water above 120 °F (49 °C). High temperatures accelerate chlorine off-gassing, causing the PPM to plunge within minutes. Always dilute bleach with cool water and retest if the solution warms during use.

No. Mixing different sanitizer chemistries can neutralize their effectiveness and create harmful by-products. Use separate sinks or buckets for each chemical, rinse wares thoroughly between sanitizers, and clearly label all containers to prevent mix-ups.

The Georgia Food Code defers to the manufacturer’s label for quaternary ammonium products. Some newer blends work at 150 ppm while others need 400 ppm for the same kill rate. Always read the concentrate label or the dispenser placard and match your test strip scale. When in doubt, hold 200 ppm—Georgia inspectors accept that as a safe default. For more detail on labelled use rates, review the Georgia Food Code summary.

Most strips use colour blocks in 50 or 100 ppm increments. After dipping, compare the strip within ten seconds—waiting longer skews colours. If the shade falls between blocks, round down and adjust the solution. Digital photometer strips give a precise number but cost more. Learn practical strip techniques in our cleaning & sanitizing guide.

Minerals like calcium bind active ingredients, especially quats. Your 200 ppm reading may deliver far less microbial kill in very hard water. Use a water-softening unit on the sanitizer line or increase contact time. For bleach, hardness is less critical but high iron leaves brown stains. Track pre- and post-mix readings and note any over-100 ppm adjustments in your logs. Visit our safe-handling practices page for more troubleshooting tips.

Field Validation Tips

Calculations are only half the battle—you must prove the numbers match real-world readings. Keep fresh test strips at every sink and in a labelled zip bag on the prep line. Dip the strip for the time stated on the package (usually five to ten seconds), shake excess water, then match against the colour scale immediately. Record the reading and initials in your sanitation log; Georgia inspectors expect to see time, ppm and corrective action if the value fell outside the acceptable window.

Common dilution errors include filling sanitizer buckets from a hose that also tops up detergent sinks, splashing detergent into the solution and neutralising active chemicals, or guessing volume rather than measuring. Use marked buckets or graduations inside the sink to gauge water level, add concentrate after water to prevent foaming, and stir with a clean utensil. If the first strip reads low, double-check your concentrate—cold bleach stored beside a freezer can stratify and weaken. Retest every four hours or whenever the solution becomes cloudy, oily or littered with food debris.

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