Verify sanitizer strength at FDA Food Code levels with Indigo® 400 ppm quat (QAC) test strips. Ensure safe food-contact surfaces in restaurants, schools, and institutional kitchens. Measure multi-quat formulations of single, dual and 4-chain quat disinfectants.
Indigo® 400 ppm quat (QAC) test strips provide fast, reliable sanitizer verification for restaurants, school cafeterias, nursing homes, & institutional kitchens. Quaternary ammonium compounds (QACs) are widely used disinfectants, but sanitizer solutions must range typically from 200 to 400 ppm, to meet FDA Food Code and local health inspection standards. These easy-to-use strips help staff and inspectors confirm compliance, prevent foodborne illness, and maintain clean, safe food-contact surfaces.
All Indigo® Quat (QAC) test strips come in 100 (not 50) strips per pack & 3 year minimum guaranteed shelf life backed by a Certificate of Analysis, Stability & SDS documents as listed below; Certificate of Conformance on request. Be prepared for any health & safety audit or inspection.
Best Practices for Using 400 ppm Quat (QAC) Test Strips
Maintain Effective Concentration: Keep sanitizer solutions within the FDA Food Code range of 200–400 ppm. This ensures strong pathogen control without leaving excessive residues.
Mix Fresh Daily: Quat sanitizers degrade over time. Always prepare fresh solutions at the start of each shift.
Test Frequently: Use strips to check sanitizer levels at least once per shift, and whenever solutions are remixed, diluted, or look cloudy.
Document Results: Maintain a sanitizer logbook for HACCP, FSMA, or local health inspections. Inspectors often ask for proof of consistent monitoring.
Correct Quickly: If strips read below 200 ppm, remix sanitizer. If above 400 ppm, dilute with potable water until within range.
Train Staff Consistently: Ensure every employee can correctly dip, read, and record test results using the strip and color chart.
This test strip can measure the strength of many multi-quat formulations of single, dual and 4-chain quat disinfectants as listed in Quaternary Ammonium Compounds. You can even compare their chemical structures with the Indigo®3D Molecular Model Builder.
Related information or images
Healthcare/Hospitals
Schools-Daycare
Transportation Foodservice
Catering, Mobile Food Vendors
Restaurants & Foodservice
White Rice Processing
Specifications
Temperature and QAC strips reading relationship
Temperature vs ppm results for commercial formulations of quaternary amine sanitizers/disinfectants from 20 to 60oC (68-140F).
50, 100 ppm read~ 1/2 color square higher; 200, 400 ppm read 1 color square higher
55/131
Readings 1 color square higher across whole range
60/140
Readings 1 color square higher across whole range
Dip strip for 1-2 seconds & get readings in 10 seconds at 0-100-200-400 ppm for quaternary ammonium disinfectant concentration. Read strip results immediately. If you wait the 30 seconds needed for some other strips you will get a reading that is too high.
Indigo® test strips have a guaranteed minimum 3 year shelf life but are stored in desiccant lined vials so actual shelf life can be 5+ years.
They work wonderfully, was so happy to finally solve my sanitizer testing problems and to use hot water is great as well.
— Cindy
— Indigo:
Thanks for letting us know your experience with hot water. The chemist who designed the strips even provided us with instructions on what to expect when using hot water with quats.
2018-01-09
Great product as always and excellent service.
— john
2017-09-20
Excellent product- temperature range is far more liberal and fits our needs. State surveyor recommended! Down side is cost may be a factor considering old strips are provided for free from our vendor.
— Brett Anderson
— Indigo:
If you are using old strips, be careful as they may not be accurate. We in fact guarantee ours for 3 years minimum.Â
2017-08-08
The order came very quickly and is producing the results we hoped for when ordering this product
Thanks for noting our prices. Our discounts start at just 2 it costs the same to as 1.