Public Lab Research note

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Hydrogen sulfide badges by Morphix Technologies

by gretchengehrke |

Hi Folks! I just found these hydrogen sulfide passive samplers that are made by Morphix Technologies.

They involve a color-change reaction that appears to be triggered when the accumulated hydrogen sulfide in the badge (after a semipermeable membrane) reaches a certain concentration that corresponds to 2.0 ppm per hour, and at that point there is sufficient hydrogen sulfide to react with the substrate to change color. So, for example, if the badge were worn for 8 hours in a house with 0.25 ppm hydrogen sulfide, the badge would change colors after 8 hours. It's not clear to me if there is a progressive color change that correlates with concentration above that minimum threshold, or if there is no change in color intensity with increased hydrogen sulfide concentration.

The product information sheet can be found here:, and the patent for the general concept of the badge can be found here: The product information sheet and patent don't disclose the chemicals that are reacting with hydrogen sulfide to produce the color change, so it's not easy to discern if there are likely interferences or co-contaminants (the product info sheet says there aren't any known interferences, but without explicit info about what has been tested, I wouldn't want to take that at face value). That said, they are used in industrial settings and have a low enough detection limit that they are useful at health-relevant warning levels (see the Acute Exposure Guideline Levels here:

We're thinking about using these badges alongside a couple of DIY hydrogen sulfide detection methods, including a silver halide photopaper method ( and an elemental copper rod method ( Has anyone used these Morphix Technologies badges before, or something similar. They cost $160.65 for a pack of 50 (and have a shelf life of 2 years), so they could be a fairly readily available option. Please comment below if you have used them or something like them, or know what chemicals they use!

hydrogen-sulfide-sensing hydrogen-sulfide air-quality


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