Steaks sizzling on the grill. Bread baking. Summer rain on hot sidewalks. These are just a few of the ten thousand different odors scientists say your nose can detect. The human nose is lined with more than ten million cilia – microscopic hairs covered with receptors sensitive to airborne odor molecules. Those tiny receptors trigger our reactions to the smells around us. If the smell is pleasant, no problem. But if it’s a malodor, that’s a different story.

“Most odors, good and bad, are created by a human element,by processes that are going on inside a facility,” says Roger McFadden, vice president of technical services for Oregon-based Coastwide Laboratories.

While human activities may start the process, most experts agree germs and bacteria from those processes are the cause of malodors. Porous surfaces such as grout can trap odors and the bacteria that cause them, making restrooms a primary concern for odor problems, says Evan Kolb, director of business development, Superior Building Services, Orlando, Fla.

Also, watch out for the janitor’s closet, says Steve Ashkin, president of the Ashkin Group in Indiana.

“Sometimes when we’re storing chemicals we may spill a little, or the caps aren’t on tight. We also store mops, buckets and years of junk and garbage,” he says, adding that the HVAC system can circulate those odors through an entire building.

We all know that foul odors are signs that something isn’t sanitary, but pine, bleach and lemon scents don’t actually mean the room is clean, either.

“If you walk into a restroom and you smell nothing, that would be clean,” says Jim Gambino, vice president of specialty services for CleanPower, Milwaukee. “Fragrance isn’t proof the area is clean.”

“We’ve indoctrinated consumers that clean smells like something,” says Ashkin. “We need to re-educate people to the concept that there is no odor. Cleaning shouldn’t have a smell.”

“Traditionally, cleaning products have been scented to give the appearance of deodorizing,” adds Patrick Stewart, president of EnvirOx, an Illinois chemical manufacturer. “ Our opinion is they interfere with the task. They cover up odors so you don’t know whether you’ve fixed the problem.”

Getting rid of odor
Before a room can be deodorized, find out where the odor is coming from, says Stewart.

“You can have a clean restroom but a negative sealing sewer system and it will stink no matter what you do,” he says.

For instance, check floor drains.

“They’re a window right into the sewer line. Make sure there is water in the trap to prevent sewer gas from entering,” Kolb advises.

Poor ventilation also can be a culprit. McFadden recommends checking air vents and filters at least quarterly, and cleaning or replacing them as needed.

Also, buildings with proper ventilation can have problems if the air-handling systems are shut down at night, adds Gambino.

But, regardless of the ventilation, surfaces must be clean before they can be odor-free.

“We clean restrooms thoroughly,” Ashkin notes. “Thoroughly wrong. We assess cleaning based on appearance. If it looks clean we think it is clean. To prevent odors what we have to do is not a one-time kill of bacteria on the surface. We have to remove the food source. If we don’t do that, the odors keep coming back over and over again.”

Frequent cleaning can help, suggests Kolb.

“The grout is where all the odor bacteria and germs hide,” he says. “If you’re cleaning ceramic tile or regular quarry tile, you have to have a regular schedule of machine scrubbing.”

Since urine odors are a problem in many restrooms, CleanPower is experimenting with sealing small areas of ceramic tile in front of urinals. Gambino also is investigating new disposable floor mats to go under urinals.

To prevent germs and malodors from spreading, CleanPower employees use disposable cleaning cloths.

“I believe it’s more sanitary than regular cloths,” Gambino says. “You’re getting a clean applicator every time.”

Other contractors are using color-coded microfiber cloths. The color coding prevents cross contamination and the microfibers have been proven more effective than traditional cloths at capturing and removing soil.

Choosing control
After cleaning, contractors still may need to use a chemical agent to get rid of the odors. McFadden, a chemical engineer, says there basically are four ways to control malodors: masking, oxidizing, enzymes and counteractants. Masking is the most common and worst solution to odor control, he says.

“Anything you’re putting into the air is artificial,” Kolb agrees. “It’s adding to the problem, not alleviating it. To mask odors is to nullify all of your efforts. If you have to mask something, your problem is not the odor, it’s the cleaning.”

However, clients often want a fragrance for transient odors, in which case a scented air freshener makes sense.

“I think it’s the perception that if it smells clean the brain tells you it is clean,” Gambino says. He believes customers see cherry and orange scents as masks, but neutral, outdoorsy fragrances are preferred.

Oxidizers, on the other hand, are McFadden’s preferred method of odor control. These products use an oxidizing chemical such as hydrogen peroxide or chlorine and expose the agent to the malodor.

McFadden cautions that oxidizers can be harmful and damage surfaces if not used properly. But he likes the downstream effects of hydrogen oxidizers; hydrogen peroxide breaks down into water when it’s finished doing it’s job.

Enzyme catalysts are another form of odor control that McFadden says are growing in popularity.

“They degrade the odorous compound itself,” he explains. Enzymes work primarily on organic materials and certain types of proteins.

Counteractants, chemical agents that attach themselves to odor molecules without adding a scent of their own, are the fourth control method. Ashkin says the industry has been looking at these compounds for the last ten years or so, but there still may be some health questions about these methods.

When deciding which products to use, choose products that require less labor, but are effective and have the least capability to cause health or facility damage, suggests Stewart.

Also, carefully review material safety data sheets, says Ashkin. Sometimes, the sheet will simply say “fragrance” — a concession the government allows to help manufacturers protect proprietary formulas. But some formulas contain benzene, a carcinogen, and aromatic hydrocarbons – respiratory irritants that also can affect the nervous system. Ask the supplier for specifics, and don’t buy if they won’t share the information.

Jennifer C. Jones is a frequent contributor to Contracting Profits. She is based in Salt Lake City.