Invisible Sentinel: Autoclave Indicator Labels



Invisible Sentinel Inc. specializes in developing microbial detection tools for food and beverage manufacturers and 3rd party testing labs. The work that they do keeps us safe by detecting contaminants and ensures quality of the products that we buy on a daily basis. As a part of their manufacturing process, Invisible Sentinel stores different types of liquid media inside polypropylene bottles. These bottles (and media within) undergo an autoclave sterilization process. Dominic Falance, Director of Manufacturing at Invisible Sentinel, wanted to introduce a better way to distinguish the difference between each type of media by integrating a color-coded labeling system to the bottles. After searching online, he found CleanMark and brought his ideas forward so we could bring them to life.

The Challenge & Requirements

One main challenge that Invisible Sentinel faced was finding a label manufacturer who could produce custom sized labels in small quantities. Also, their existing method for showing proof of sterilization included applying and removing autoclave indicating tape to the bottles in addition to a separate product label. Dominic preferred to switch to a single label that would serve both functions simultaneously. Each label was to be assigned its own color to specify 12 different types of media. After the autoclave process was complete, the label must be removed but one challenge still remained; how would they be able to distinguish which media was inside each bottle? With Dominic’s idea, CleanMark created a separate outer-ring label, each with a matching color that correlated to the previous autoclave indicating label (see photo). Once the initial label was removed, their manufacturing team could now easily determine the corresponding media.

The Process & Solution

Dominic’s ideas helped CleanMark’s Engineers to select the proper materials needed for each unique label. The outer ring label needed and an aggressive adhesive that would last while the autoclave indicating label needed a material+adhesive combination that could be easily removed within 3-5 days. What’s more; part of Invisible Sentinel’s manufacturing process involved placing these bottles (and labels) through a vigorous laboratory wash machine cycle. This particular wash cycle would expose the labels to harsh chemicals such as IPA & Lancer-acid. It was critical that CleanMark could produce a label that would survive all aspects of this process while maintaining its integrity, legibility and color. After a round of free material sampling, Dominic was able to evaluate the performance of CleanMark’s recommended labels on the bottles, through the autoclave sterilization process, and through the lab wash cycle.

“CleanMark was able to help us bring a rough idea to fruition at a very competitive cost. Their expertise with labels made the process very simple as they guided us through everything.”

Dominic Falance, Director of Manufacturing at Invisible Sentinel

The Results

With an understanding of Invisible Sentinel’s goals, CleanMark was able to develop a custom labeling system that served several purposes while saving them money. This also simplified their existing process by removing the need for separately applying and removing autoclave indicating tape. Now Invisible Sentinel has a go-to resource that they trust for their label needs.

Autoclave Labels

CleanMark offers autoclave sterile indicator labels that use a color changing ink to show when the label has went through the autoclave process. Learn more about the autoclave labels we offer and how we might be able to help.


Cameron McKillop