Choose from 4 different Indigo® quaternary ammonium chloride test strips for disinfection & sanitizing needs in restaurants, hospitals, organic farming & more.
All come with 100 test strips/vial, a guaranteed 3 year minimum shelf life. Full documentation provided on-line for Certificates of Analysis, Stability & SDS Statements; Certificates of Conformance available on request. Optional next day delivery in any quantity of most items.
Buy Indigo® test strips, the brand you can trust for accuracy & technical support. Call us on our toll free line for immediate assistance or e-mail us with your questions. 1 hour response is typical during business hours, M-F, slightly longer on weekends.
Quaternary ammonium compounds are cationic surfactants (positively charged surface-active agents) that are more chemically complex than other disinfectants. Their name derives from the central nitrogen that is bound to four (quaternary) organic groups. They interfere with the metabolism of Gram-negative & Gram-positive vegetative bacteria and lipophilic viruses. Quats are especially effective on hard, non-porous surfaces. They are used in a broad range of places from hospitals, long-term care facilities, households, and essential workplaces such as grocery stores and food processing plants to high traffic outdoor common areas and public transit systems.
Quaternary ammonium compounds are also referred to as cationic detergents. They are a class of synthetic detergents made up of long chain hydrocarbons in which the molecule has a positive charge (a cation) in water. There are quaternary ammonium salts of amines with acetates, chlorides or bromides as their complementary anions. They are useful as wetting & emulsifying agents in acidic or neutral pH solutions, fabric softeners & as microbicides and fungicides.
Whatever formulation of quaternary ammonium you use, Indigo® quat test strips can confirm your disinfectant solutions are correctly diluted for optimum effectiveness.
Note: All test strips Made in the USA & are Q/A'd against NIST standards.
Quaternary ammonium chloride solutions come in many varieties. Ours are calibrated for Oasis 146 but can accurately test any simple or multiquat formulation using compounds such as these: benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetalkonium chloride, cetylpyridinium chloride, cetrimonium, cetrimide, diisobutylphenoxyethoxyethyl dimethyl benzyl ammonium chloride,dofanium chloride, tetraethylammonium bromide, didecyldimethylammonium chloride, etc. You can view & compare their different chemical structures using our 3D Molecular Model Builder.
Additional material that may interest you:
Quat test strips do not measure the concentration of dissolved quaternary ammonium compounds (QACs) directly. They actually use acidobasic indicators (normally used for pH determination), buffers, surfactants, and other ingredients to create a micro-environment on the test pad where the indicator dyes react to the presence of the quat and not to the pH of the test solution. It is as a consequence of the interaction between the molecules of the indicator dyes and quat that results in a different color of the test pad that we observe.
This is based on what is known as the "pH indicator error" (when the indicators change color without a change in solution pH) which relies on a carefully calculated amount of buffer on the test strip that excludes any contribution to pH other than the quat itself. It is this "error" that is utilized for the detection of compounds of interest (The QACs in this case). In other words, the assumption is the quat has been dissolved in tap water that might be slightly acidic, neutral or slightly alkaline. "Alkaline water" for example would have absolutely no effect. However, some quat formulations have additives such as tetrasodium EDTA which strongly shifts pH towards an alkaline level of 11-12 that completely throws off the test strip reading.
Overall, this is a reliable semi quantitative test method that is accurate typically to +/- 10% & suitable for confirming the correct dilution of quat concentrates in the "field". For more precise lab work, instruments such as GC/MS can deliver quantitative results on the order of several magnitudes greater & over a wider dynamic range.
35oC: Readings ok for 0-400ppm
40oC: Readings ok for 0-400ppm
45oC: 0, 50, 100 ppm readings ok; 200 & 400 ppm read~ 1/2 color square higher
50oC: 50, 100 ppm read~ 1/2 color square higher; 200, 400 ppm read 1 color square higher
55oC: Readings 1 color square higher across whole range
60oC: Readings 1 color square higher across whole range
Follow the directions on the label. All our quat strips are "quick response". Dip the strip & compare to the color chart within 5-10 seconds. If you wait a minute as with other strips, the color will develop further & give a false high reading.
Some sources have raised concerns about the safety of quaternary ammonium compounds. Handling concentrated QACs may merit wearing PPC such as gloves, eye protection and even a respirator.
Yes. These didecyl dimethyl ammonium chloride, alkyl(C12-C16) dimethyl benzyl ammonium chloride, octyl decyl dimethyl ammonium chloride, dioctyl dimethyl ammonium chloride and others have been shown to kill molds. Read more in our blog: Quaternary Ammonium Compounds-Organic Disinfectants. If you are interested in the chemical structures of these compounds, you can view them in our 3D Molecular Model Builder.
Absolutely not! Mixing concentrated chlorine bleach & quaternary ammonia compounds can produce toxic vapors.
Chlorine bleach contains sodium hypochlorite, a powerful oxidizing agent that can corrode most metals & react to produce toxic chlorine gas. Its principle advantage is that it is cheap & readily available. Quats are cationic detergents that are relatively low in toxicity by comparison but its surfactant nature produces a residual film with broad spectrum germicidal characteristics.
According to the Household & Commercial Products Association (HCPA): "Quats are a well-understood and effective class of chemicals, usually classified under the chemical names ADBAC and DDAC. Numerous reputable studies show no sign of systemic toxicity in humans".
On the other hand, some articles do question the safety of quats. Considering the importance of surfactants in lung alveoli, it may be prudent to handle concentrated quats only in well ventilated areas or wear a respirator and goggles during the dilution process.