Ensure dairy and cheese products meet HACCP, FSMA, and export standards. Indigo® residual quat test strips verify sanitizer residues are at safe levels, assuring consumers, including those with lactose intolerance, while supporting inspections and clean-label claims.
Maintaining safe and compliant production environments is critical in the dairy and cheese industry, where sanitation controls affect everything from pasteurization equipment to aging rooms and packaging lines. Indigo® residual quat (QAC) test strips (0–100 ppm, sensitive down to 10 ppm) allow processors to confirm that sanitizer residues remain at safe, regulated levels. This not only ensures compliance with HACCP, FSMA, and export inspection standards but also builds trust among consumers. For customers with dietary sensitivities, confidence in both food quality and sanitation practices is essential. Verifying low quat residues helps support clean-label commitments, protect brand integrity, and satisfy increasingly strict inspection protocols.
Targeted Sanitation Cycles:
-Clean brining tanks, pasteurizers, and cutting equipment with validated quat-based sanitizers.
-Rotate sanitizers when possible to reduce microbial resistance.
Residual Verification with Test Strips:
-Use Indigo® 0–100 ppm quat test strips during final rinse checks.
-Record results in HACCP logs to meet FSMA and export audit requirements.
Protect Sensitive Consumers:
-Maintain low sanitizer residues typically ≤100 ppm on food-contact surfaces, with reliable detection down to 10 ppm to support allergen-aware, organic, or “lactose-free” product labelling.
-Reinforce consumer trust by exceeding regulatory minimums.
Integrate with Preventive Controls:
-Pair residual testing with ATP swabs, pH monitoring, and microbial testing.
-Align with Preventive Controls Qualified Individual (PCQI) plans under FSMA.
Audit-Ready Documentation:
-Keep digital or paper logs of quat strip results.
-Cross-reference results with sanitation SOPs to ensure inspection readiness.
Continuous Staff Training:
-Train employees to properly use quat test strips and interpret results.
-Include refresher training during seasonal production peaks.
The directions on the test strip bottle are for testing liquid quat solutions.
Test surfaces for residues by first wetting the strip's testing pad with water (deionized or distilled if available). Then press against fruits, vegetables, cutting boards, utensils, etc. for at least 10 seconds & then compare against the color chart.
Levels less than "10" ppm are impossible to determine but some organic certifications call for "0" ppm. This is because water alone causes a reading of 10ppm. Read more in our blog on What 10ppm really means? when measured on surfaces of knives, cutting boards, fruits or vegetables.
Related information or images
Residual Quat 10-100 ppm
Berries
Fermented Foods
Grains-Nuts
Leafy Greens
Microgreens-Sprouts
Wild Organic Rice
Specifications
Swish strip in liquid 5 times & then compare to color chart after 10 seconds.
Read ≤10-30-60-80-100ppm ppm for quaternary ammonium disinfectant concentration.
Indigo® quat test strips have a guaranteed minimum 3 year shelf life but desiccant lined vials allow for 5+ years.
Store at 20-30C, in a dry place out of direct sunlight.
Indigo® QAC test strips are calibrated for Oasis 146, see details.
Consult your supplier if any special testing is necessary for their formulation.
Solution temperatures from ~30-45C can cause strips to read up to ½ unit a chart unit higher.
Temperatures above 45C can shift the results 1 chart unit higher. Testing at room temperature
Hard water (above 500 ppm) can cause the strips to read high by up to 1 chart unit.
The number of strips (100) per vial is approximate.
