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.

Best Practices for Using Indigo® 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.

Indigo® 0-400ppm Quat Test Strip Specifications

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.

Quats are measured at 0, 100, 200, 300, 400 ppm.
Quat test strips have a detection limit of 25 ppm.
Indigo® quat test strips have a guaranteed minimum 3 year shelf life but can be 5+ years if stored properly.
Store in a cool (20-30C), dry, place out of direct sunlight.
Formula additives can adversely influence the results. Use with formulations other than Oasis 146 should be verified first
The number of strips (100) per vial is approximate.

Temperature and QAC strips reading relationship

Temperature vs ppm results for commercial formulations of quaternary amine compounds from 20 to 60^oC (68-140F).

T (^oC/^oF)	QAC strips readings at: 0; 50; 100; 200; 400 ppm
20/68	Readings ok for 0-400ppm
25/77	Readings ok for 0-400ppm
30/86	Readings ok for 0-400ppm
35/95	Readings ok for 0-400ppm
40/104	Readings ok for 0-400ppm
45/113	0, 50, 100 ppm readings ok; 200 & 400 ppm read~ 1/2 color square higher
50/122	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

Documents:

Stability Statement

Certificate of Analysis

Download SDS

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