Hes well ahead of the microscopic curve
Krueger is the founder and president of Summit Laboratory of Grand Rapids, which opened a second lab facility in Hart and is launching a marketing campaign to expand into five other Great Lakes states with nearly 15,000 potential client companies.
The lab in Hart was opened a couple of years ago to serve fruit and vegetable processors in the region. Most of Summit Laboratory's work involves testing for food processors, but the company, which now employs about a dozen people, also tests indoor air quality, mainly in regard to contamination with black mold.
Krueger is a board member of the Grand Rapids chapter of the Indoor Air Quality Association.
Krueger was born and raised on Chicago's south side, where his father was a violent crimes detective with the Chicago Police Department. As a teenager, he had a city job as a pool lifeguard, and with his family connections, he knew he could try for a career on the police force. But there was something else that he was more passionate about: biology. Although he knew biology would be a "bumpier" career path, "I didn't want to look back and think about myself as the guy who took the easy road."
His first two years of college were at the University of Illinois in Chicago. Then he decided to see if he could finish his education in Michigan and learned that the Grand Valley State University biology department had its students in the field a lot — "and that really captured my imagination," he said.
His parents couldn't pay much of his college expenses so he was working his way through school. He showed up two days before the start of the fall term at GVSU with his meager belongings — "no place to live, no job, not registered for class and very little money in my pocket." Despite that, he started classes and found work as a GVSU pool lifeguard, then landed a better job as a research assistant, taking samples of the Grand River for the GVSU Water Resource Institute.
"That was great experience," he said.
In 1990, about four months before he graduated with a degree in biology, he accepted a job at AAT Labs Inc. on Buchanan SW in Grand Rapids as a staff biologist and chemist. His work included microbiological examination of various food products and water, and he also worked with several lake associations to develop lake management plans. Other lab work he did involved chemical analysis of hazardous and non-hazardous industrial waste, and quantitative air testing for mold, carbon monoxide, carbon dioxide, various nitrogen compounds and hydrogen dioxide.
Thomas J. Krueger
Thomas J. Krueger
Around 2006, when Summit had four employees and was outgrowing its lab space, Krueger discovered that one of his competitors, Fettig Laboratory at 900 Godfrey Ave. SW, was going out of business, and its property, equipment and client list were for sale. Summit acquired the Fettig assets, and that is where Summit's headquarters are today.
The most frequent work done at Summit is analyzing swab samples from food-processing machinery and surfaces that contact food in processing.
"Not only do they have to have their products tested to demonstrate they're pathogen free, they have to have their processing equipment tested on a regular basis," said Krueger.
"People ask me, what is the (legal) limit for bacteria on a food-processing surface?" he said. "There is none. There are no laws, state or local, that have set a microbiological limit on a food contact surface."
But corporations such as General Mills and Kellogg that buy and resell processed food demand frequent proof from the processors that it is safe, he said. "And then they say, 'Oh, by the way, you can't test it yourself. You have to have an independent third party — an accredited lab.'
"The accredited part is the newest of the criteria being put on these food processors," said Krueger. "We anticipated that requirement being put on the processors a couple of years ago." Summit Laboratory recently received its ISO 17025 accreditation for its Grand Rapids and Hart facilities.
"These food processors are now required to have in place what's called a food safety management system," he said. "Again, this restriction didn't come from government. It came from within the industry itself. It's a value-add for these food processors to be able to say, 'We're HACCP certified,'" he said. Krueger has been an HACCP-certified microbiologist since 2000. Pronounced "hassip," HACCP stands for Hazard Analysis Critical Control Points.
Krueger said food processors in West Michigan "were already ahead of the industry curve. These are clean, efficient, well-run companies in West Michigan."
Unlike dairy, meat and poultry processing, in which high-temperature processing and aggressive disinfectant techniques with very hot water combat microbes, one of the most at-risk foods to produce in West Michigan are fresh blueberries. Blueberries grow near the ground — soil is a major source of microbes — and the fruit is too delicate to tolerate an aggressive sanitization process if it is intended for the fresh market. Krueger isn't saying fresh Michigan berries are risky; they just take more care than other crops.
But the real horror stories in Krueger's work are not food-related; they revolve around black mold, the bane of the real estate industry, facility managers, landlords, builders and construction companies.
Krueger has attended several seminars on black mold and its impact on indoor air quality, and in 2002 and 2003, he received several certifications pertaining to mold investigation and remediation. He has served as an expert witness in at least six lawsuits involving black mold in structures.
Around the time he started Summit Laboratory, black mold, also known as "toxic mold," began to receive a lot of attention. "It created a new industry for doing mold inspections in residential and commercial buildings," said Krueger.
A runaway mold colony can lead to serious health risks; some molds can produce 400 million spores per square inch. For the most part, he said, black mold "has always been there, but it's been exacerbated by two things. Buildings are tighter than they used to be, so there is less air exchange." The other change is the use of building materials that are more susceptible to mold colonization in humid conditions. Krueger said one such product is OSB — oriented strand board — which he said is basically cellulose, and molds love to consume it. Another product is modern drywall, because it has paper liners made from cellulose.
Krueger said his company has tested indoor air quality in buildings where workers complained of upper respiratory illness. "Sometimes it is mold; sometimes it is something related to the office environment, like toner dust." Mold needs only 60 percent relative humidity for spore germination to occur, he said, so he recommends keeping the humidity between 30 and 50 percent.