As almost all cleaning professionals know, there are three terms that apply to chemicals used in cleaning: acid, alkaline, or neutral. The pH scale ranges from 1 to 14 and is a measure of a solution’s acidity or alkalinity. A pH of 7 is neutral; a pH less than 7 is acidic; and a pH greater than 7 is alkaline, or basic.

Various categories of cleaners are formulated by manufactures as acidic or alkaline because of their effectiveness in cleaning or dissolving certain soil types. Oven cleaners, for example, are formulated to be strongly alkaline because alkaline solutions are effective at breaking down baked-on protein, fatty soils, and the types of carbonized soils often found in and on dirty ovens. Toilet cleaners, on the other hand, tend to be acidic for dissolving water scale and rust.

The Relative Safety Concerns of High And Low pH Chemicals
Safety is a relative term. It can be evaluated on a number of fronts including: acute toxicity concern from immediate contact with a cleaner; long-term human health exposure; safety for the environment; safety for surfaces cleaned; building safety measures such as odor sensitivities of occupants.

Solutions with a significantly high and low pH levels have the potential to be very dangerous to humans, whether ingested, inhaled, or contacted with skin. Highly alkaline or acidic solutions can cause severe skin burns. In contrast, since the pH level of the human body is close to neutral — approximately 7.4 pH — workers who come into contact with neutral chemicals are at minimal risk for more than skin irritation.

Not directly associated to the pH level of a cleaning solution, but related, is the new Globally Harmonized System (GHS) for classification of chemicals. It requires all commercial chemical labels to display pictures (“pictograms”) of the relative safety of the chemical on nine pre-defined metrics. Three of them are related to immediate human health concerns and one is related to long-term health.

Very high and very low pH cleaners carry with them concerns that pertain specifically to the health of the user and building occupants. These products not only can prove corrosive, but depending on the type of surfaces they are used on, they can cause toxic fumes as well. This is especially common when applied to metal surfaces. (These types of chemicals would contain a “corrosive” pictogram.)

A highly acidic product — with a pH below 2 for example — may prove corrosive and destroy or damage materials it comes in contact with. A formulation that is highly alkaline – perhaps a pH of 12 or above – might be corrosive and burn or dissolve materials.

Making matters worse, fumes associated with highly acidic or alkaline chemicals can often become transported via HVAC air ducts, and travel throughout an entire facility, leading to occupant confusion, loss of worker productivity, poor concentration, and in some cases, an evacuation.

A pH Neutral Alternative
With the safety-related disadvantages of acid and alkaline cleaners, one could conclude that pH neutral cleaners might be the ideal solution. After all, neutral pH cleaners are less likely to cause adverse health effects and harm surfaces, and more likely to be safer for users and the environment.
But while a neutral formulation might be safer, the cleaning strength and efficacy of neutral cleaners has historically been lower than caustic and acidic cleaners, especially on certain types of soils. For a cleaning professional, might an ideal solution be one that has the effectiveness of extreme pH cleaners along with the safety of neutral cleaners?

Nyco Products Company believes so. They believe they have addressed this precise challenge in a line of pH neutral cleaners [6.0 - 8.0], called OM1, which are formulated with a new solvent from Eastman Chemical Company.

“Over the last decade, formulators (manufacturers) have tried to respond to increasing concerns from their end customers about the safety of the people who clean our hospitals, schools, and businesses,” says Carol Perkins, industry leader for industrial and household care at Eastman. While many [cleaning chemical alternatives] have been developed that are greener and safer, users continued to experience poor cleaning results from them, especially when dealing with heavy soiling.“

Stephen P. Ashkin is president of The Ashkin Group, a consulting firm specializing in Greening the cleaning industry, and CEO of Sustainability Dashboard Tools, which offers a cloud-based dashboard that allows organizations to measure, report and improve their sustainability efforts. He is a member of the prestigious International Green Industry Hall of Fame, and is coauthor of both The Business of Green Cleaning and Green Cleaning for Dummies.