This Professional Pot-Sniffing Device Is Being Used To Smell Test Gates-Funded Toilets

Like a loudspeaker for your nose, the Nasal Ranger can tell when a smell is too smelly. That’s an important factor when testing whether an innovative toilet is going to change the world.


“All of the sudden people learn about your product because someone talks about pot, and everybody listens,” says Mike McGinley, lab director at St. Croix Sensory. We were discussing the company’s signature professional-grade smell detection tool, the Nasal Ranger. He seemed resigned that this would be the reality.


When he first learned that the Nasal Ranger was making the rounds on the Internet last week for helping Denver officials investigate secondhand pot-smoke nuisance complaints, McGinley laughed. Then he and his family of environmental engineers and teachers did what they always did when the Nasal Ranger popped up in the news–they buckled down and prepared for the barrage of phone calls at their St. Croix, Minnesota headquarters.

The Nasal Ranger has that effect on people every few years, explains McGinley. Shaped like a loudspeaker for your nose, the Nasal Ranger, or “odor scope,” calculates the “dilution-to-threshold” (D/T) ratio of the smell in question. If the D/T shows that the number of dilutions of filtered air needed to make the smell go away is bigger than the legal limit–in Denver’s case, a 7-1 ratio–the local Department of Environmental Protection can issue a violation for secondhand smoke breaking the city’s odor law.

But the Nasal Ranger is more than just an odor-detecting narc–or, in many cases, scientific justification to dismiss NIMBY complaints of smells that barely register. The Nasal Ranger has been in action for more than a decade, and today, researchers funded by the Bill and Melinda Gates Foundation are also using the Nasal Ranger to test improved toilet designs in India and Ghana.

The McGinleys have been in the business of field olfactometry since the ‘70s, when environmental engineer Charles McGinley (Mike McGinley’s father) started his own consulting business for companies looking to improve their industrial smells. Most sensory engineers up until that point had relied on something called the Scentometer, a similar device with two glass tubes with bulbs on the end that go up the user’s nostrils, invented in 1958. The Nasal Ranger, however, uses a soft nasal mask and a flow sensor that can tell users when they need to sniff harder. It was released in 2002.

Since then, the device has been used by different landfill companies, animal agriculture sites, municipalities with odor rules, and citizen groups protesting smells. But in early 2014, the Nasal Ranger will make an appearance in India, where the Gates Foundation is helping fund the design of 119 urban community toilets.

In 2007, the Gates Foundation commissioned the Potty Project, a sanitation research initiative that took place in five Indian cities between 2010 and 2011. Today, the Foundation has extended the Potty Project into Project Sammaan, which is working towards implementing Potty Project designs in Bhubaneswar and Cuttack, two cities in eastern India heavily damaged by the recent Cyclone Phailan.


In order to measure how well people engage with the new toilet designs in the slums, Pamela Dalton, a researcher with sensory science institute Monell, will be traveling to India with the Nasal Ranger this winter. “What [the Gates Foundation] realized is that beyond the design phase, one barrier that might be there to actually utilizing this is odor,” Dalton told Co.Exist. “They needed someone to actually be there to evaluate how odorous these facilities actually became and correlate that with usage data.”

Over a year and a half, Dalton and her colleagues will then train local workers to collect air samples and document odor with the Nasal Ranger. She’s also working with a Ghanaian civil engineering PhD student on a similar Gates-funded sanitation initiative in West Africa. “I think it’s really something very revolutionary,” Dalton said. “We’re realizing that odor can be a barrier to sanitation and hygiene, and if we can document it, and document best practices that reduce odor, we can convince people that it’s worthwhile to change behavior.”

McGinley predicts that the Nasal Ranger will become important to communities shifting some waste management over to composting facilities, as well as big corporations looking to decrease their environmental impact. “It’s a big area that I think will continue to grow, because people are demanding cleaner and cleaner,” McGinley said.

In the meantime, the McGinleys have also rolled out an odor-tracking tool with Google Maps. Nasal Ranger enthusiasts can map the data they’ve collected with the Nasal Ranger at

As for the renewed interest in the Nasal Ranger’s pot-sniffing capabilities, the McGinleys welcome the public curiosity about their field. “We’re a family business, and we’ve grown on teaching people, and I think even some big corporations have forgotten about that,” McGinley said. “We’re never wanting to dump somebody off the phone.”

About the author

Sydney Brownstone is a Seattle-based former staff writer at Co.Exist. She lives in a Brooklyn apartment with windows that don’t quite open, and covers environment, health, and data