Cleaning Intentionally

Indoor Environment

Posted on Feb 21, 2011 in Cleaning, Cleaning Chemicals | 0 comments

December 2010

New Technology Helps Cleaning Managers Solve Indoor Environmental Challenges

By David Mudarri, PhD

Steam vapor cleaning has been proven in the real world and validated in laboratories.

Building owners and occupants beware.  Federal legislation requires that buildings become increasingly more energy efficient over time (e.g., Building envelopes are being tightened with increased insulation, more energy efficient windows, and lower rates of outdoor air infiltration.  Efforts are also being made to keep mechanical ventilation rates to a minimum.  Why is this important for the cleaning industry?  Less outdoor air infiltration means that pollutants indoors will build up more quickly, so there is little wiggle room in indoor environments to protect the health and comfort of occupants. This is why all products used in buildings are being more closely examined for how much they pollute: from building materials to consumer products, and yes cleaning and maintenance products too.  Health conscious occupants are demanding that products used indoors pollute less but with no sacrifice of functionality.

In the cleaning industry, all major manufacturers currently have a line of green products whose chemicals are less harmful to people and the environment.  But why are not all cleaning products green? One reason is the perception that some green products don’t work as well as conventional petrochemical-based products at times (although this is changing).  So managers are using a mix of green products and conventional products to both clean and pollute less.  This takes time, some research, discussions with suppliers, and hands on experimentation to find the right mix for their facilities.  Fortunately, calibrating the product mix for what works best in different situations is made easier by advances in our ability to measure results via Integrated Cleaning and Measurement (ICM) and other programs. Certification or recognition programs such as Green Seal and EPA’s Design for the Environment (DfE) provide information and guidance for choosing green products that meet basic performance criteria.

While these efforts are laudable, they leave the cleaning industry short of its ultimate goal – to clean and disinfect effectively, with minimum cost, and zero harmful chemical residues. Remember, “green products” often still use chemicals that may have toxic effects on people and the environment, even though these effects have been greatly reduced.

In the near future, what once was considered “acceptable” reduced chemical toxicity can become “unacceptable” because ventilation rates are reduced and people are more conscious of indoor air quality, chemical sensitivities and other health concerns.  Thus today’s “green” products may become tomorrow’s “conventional” chemical cleaners having unacceptable side effects. Further, scientists are raising concern about some ingredients (e.g., terpenes found in citrus-based products containing di-limonene) common in green cleaners that react with ozone in the air to produce toxic chemical byproducts not found in the cleaners themselves.

Because of these concerns, scientists are searching for new chemical-free or renewable technologies to effectively clean and disinfect.  One such technology is the Thermal Accelerated Nano Crystal Sanitation (TANCS®) system used by Seattle based Advanced Vapor Technologies.  This surprisingly simple technology uses a specially treated low moisture steam vapor to both clean and disinfect.  In this device, a water treatment module converts the natural mineral impurities of municipal tap water into energized nano crystals in a super-heated low moisture steam vapor.  The energized crystals disrupt the cell membranes of microbial contaminants allowing the heated moisture to penetrate and destroy the organisms.  Heat and moisture under low pressure lift the dirt and soil particles from the surface and onto an absorptive pad. The technology therefore performs both as a disinfectant and a cleaner.

A defining feature of this technology is that its steam vapor carries a mere 6% water content, allowing surfaces to dry quickly. This is why it is sometimes called “dry steam”. The very short drying times enable putting the cleaned surfaces back into service quickly with reduced risk of slips and falls. Because of its low moisture content, the technology uses very little water (e.g. about 1.5 quarts per hour), an especially attractive feature in areas where moisture presents a potential for the formation of biofilms or mold growth.

The TANCS® technology compares favorably with conventional disinfectants. Independent scientific tests suggest that it is effective at killing microbial organisms with relatively short dwell times as compared to commonly used cleaner/disinfectants. Microbiotest Labs in Sterling Virginia and Nelson Labs in Salt Lake City, Utah show that a 7 second application of this technology provided a 5 –7 log reduction of a number of microorganisms. This 7 second feature was evident for all organisms tested, including viruses of concern such as the  Norovirus, Canine Parvovirus, and Avian Influenza (Bird Flu) viral strains, as well as bacteria such as E-coli, Pseudomonas aeruginosa (causes pneumonia and other illnesses), Salmonella choleraesuis, Listeria monocytogenes (Listeriosis-meningitis/encephalitis), Staphylococcus aureus (MRSA), and others.

More recent test results by Antimicrobial Test Labs of Texas, a certified EPA Good Laboratory Protocol (GLP) lab indicate microbial reductions fall into the 5 – 7 log range at remarkable 3 – 5 second  contact times.  These include even the MS2 surrogate for the small, non-enveloped viruses such as the Norwalk and Parvo, both very tough to kill.

These findings are important from an infection prevention and cross contamination standpoint because the TANCS process works very quickly, reducing the chance that live pathogens will be spread around facilities.  This contrasts with typical ‘spray and wipe ’ methods employed by service staff where chemical disinfectants are often applied incorrectly or without sufficient dwell time, resulting in microbes being dragged and deposited from surface to surface.

The steam vapor aspect of this technology makes it practical on multiple surfaces. It works on hard surfaces (e.g. as a restroom cleaner and disinfectant) as well as on upholstered furniture and carpet where the steam vapor is able to penetrate the porous materials. It can be used safely in most areas, except on heat sensitive materials (temperatures of the steam vapor can exceed 220o F).


In sum, this is a promising and renewable (non-petroleum based) cleaning technology in that it both cleans and disinfects with one application and using only tap water. Drying times on both hard and porous surfaces are rapid, and water-usage minimal.  A 3-7 second application provides an effective disinfectant on a variety of bacteria, viruses, and fungi.  It is also non- abrasive, non-toxic to users, and adds or leaves no chemical residues in the air or on surfaces.  Cleaning managers may find it useful to investigate this technology further.

Author: David Mudarri, PhD, is a former Senior Indoor Air Quality Scientist at the U.S. Environmental Protection Agency (EPA).

Leave a Comment