10.2 Chemical Sanitizers - CRITICAL!

This section is heavily tested on the ServSafe exam. Understanding the correct concentrations, temperatures, contact times, and test kit procedures can mean the difference between passing and failing.

Three Approved Chemical Sanitizers

The FDA Food Code approves three chemical sanitizers for food service operations. Each has specific requirements.

1. Chlorine Sanitizer

What it is: Chlorine-based sanitizers (sodium hypochlorite, calcium hypochlorite, or chlorine tablets) are bleach-based disinfectants.

Approved Concentration:

• $50-99 ppm$ (parts per million) - This is the ONLY approved range
• Too low = ineffective; too high = corrosive and wasted product

Required Water Temperature:

• Minimum $100°F$ (38°C)
• Works better at higher temperatures
• Do NOT use in cold water

Contact Time:

• Minimum $7 seconds$ of contact with food-contact surfaces
• Surface must remain wet with sanitizer for full duration

pH Requirement:

• pH $10$ or lower (pH above 10 reduces effectiveness)

Advantages:

• Inexpensive
• Fast-acting (7 seconds)
• Effective against most pathogens
• Works quickly in warm water

Disadvantages:

• Corrosive to metals and rubber over time
• Loses strength when exposed to light or air
• Cannot be used on certain equipment (aluminum, copper)
• Concentration drops quickly; must be changed frequently

Key Warning: Chlorine solutions lose strength over time. Check and replace sanitizer throughout the shift, not just once at the beginning of the day.

2. Iodine Sanitizer

What it is: Iodine-based sanitizers (iodine compounds like iodine solution or iodine tablets).

Approved Concentration:

• $12.5-25 ppm$ (MUCH lower than chlorine)
• This lower concentration is specific to iodine
• Still highly effective despite lower ppm

Required Water Temperature:

• Minimum $68°F$ (20°C)
• Can be used in much colder water than chlorine
• Ideal for operations with limited hot water access

Contact Time:

• Minimum $30 seconds$ of contact with food-contact surfaces
• Longer than chlorine (30 vs. 7 seconds)
• Surface must remain wet for full duration

pH Requirement:

• pH $8$ or lower
• Must be more acidic than chlorine
• If pH is too high, effectiveness drops dramatically

Advantages:

• Works in cold water (ideal for rinse water that can't be heated)
• Less corrosive than chlorine
• Good for certain food types (shellfish areas)
• More stable in solution

Disadvantages:

• Slower contact time (30 seconds vs. 7)
• Can stain some surfaces (stainless steel)
• Cannot be used by people with iodine allergies
• Slightly more expensive than chlorine

Key Warning: Iodine is absorbed into some foods and materials. Cannot be used on utensils that will touch foods with iodine concerns or on rubber/some plastic surfaces.

3. Quaternary Ammonium (Quats) Sanitizer

What it is: Quat-based sanitizers (quaternary ammonium compounds), often used in commercial operations.

Approved Concentration:

• $12.5-25 ppm$ (manufacturer dependent - ALWAYS follow label)
• Some products may require different concentrations
• Label is your guide—follow manufacturer's instructions exactly

Required Water Temperature:

• Minimum $75°F$ (24°C)
• Between chlorine (100°F+) and iodine (68°F)
• Does not work well in cold water
• Works better at higher temperatures

Contact Time:

• Minimum $30 seconds$ of contact with food-contact surfaces
• Same as iodine
• Surface must remain wet for full duration

pH Requirement:

• pH $5$ or higher (or per manufacturer)
• Works best in neutral to alkaline solution
• Cannot be used in very acidic environments

Advantages:

• Less corrosive than chlorine
• Does not stain food or surfaces
• Works on most food types and equipment
• More expensive but longer shelf life
• Better for hard water

Disadvantages:

• Slower contact time (30 seconds)
• More expensive than chlorine or iodine
• Requires higher minimum temperature than iodine
• Can leave residue on some surfaces
• Less effective on certain pathogens (Norovirus)

Key Warning: Quats are NOT approved for use in some jurisdictions. Check local health codes before using.

Comparison Table: Chemical Sanitizers

*Always follow manufacturer instructions for quats—concentration and requirements may vary by product

How to Use a Test Kit (CRITICAL!)

A sanitizer test kit measures the concentration (ppm) of your sanitizing solution. You MUST use a test kit to verify:

• Your sanitizer is at the correct concentration
• The sanitizer is still effective (hasn't degraded)
• You're using the right amount of sanitizer for the water

Steps to Test Sanitizer Concentration:

1. Select the correct test kit - Use a kit made specifically for your sanitizer type

   • Chlorine kit ≠ Iodine kit ≠ Quat kit
   • Wrong kit = inaccurate reading

2. Fill test vial - Use a clean vial (provided with kit)

   • Fill to the line marked on the vial with sanitizer solution
   • Not your water—the SOLUTION from your sink

3. Add test reagent - Add the reagent (solution or tablet) per kit instructions

   • Different kits use different reagents
   • Follow timing instructions exactly

4. Compare to color chart - Hold the vial up to the color chart

   • Find the color that matches your solution
   • Read the corresponding ppm value

5. Take corrective action:

   • Too low: Increase concentration by adding more sanitizer
   • Too high: Dilute with fresh water or drain and refill
   • Correct: Continue using and test again before next batch

6. Document results - Log the test time and concentration

   • Health inspectors require records of sanitizer testing
   • Keep records for 2 years minimum

Testing Frequency:

• At the start of each shift
• Every 2-4 hours during service
• Whenever you notice the solution looks weak or discolored
• Immediately after refilling basins

Key Test Kit Facts:

• Test kits are color-change or digital meters
• Color-change strips turn colors based on concentration
• Digital meters give precise ppm readings
• Never use a chlorine kit to test iodine—results will be inaccurate
• Keep test kits away from heat and direct sunlight

When Sanitizers Become Ineffective

Sanitizers lose effectiveness over time. Replace your sanitizing solution:

• Immediately if the concentration is below the minimum ppm
• Every 4 hours during continuous use (or per health department requirements)
• When visibly contaminated (food particles, grease, dirt visible)
• At the end of the shift (always start fresh next shift)

Never reuse old sanitizer. Drain and refill basins with fresh solution.

Critical Exam Points (Memorize These!)

✓ Chlorine: 50-99 ppm, 100°F+, 7 seconds contact ✓ Iodine: 12.5-25 ppm, 68°F+, 30 seconds contact ✓ Quats: 12.5-25 ppm (per label), 75°F+, 30 seconds contact ✓ Always use the correct test kit for your sanitizer ✓ Test sanitizer concentration at the start of shift and every 2-4 hours ✓ Never skip sanitizer verification—bacteria don't take breaks!