The method proposed herein has been in use for more than a year, and facility managers and building service contractors (BSCs) have found it helpful in their institutions.
Product risks are determined for current products and candidates for replacement. The results are quantifiable.
The method has two main parts: The first calculates the intrinsic risk of the product by analysis of the individual hazardous components; the second calculates the potential risk of exposure by determining the concentrations of hazardous components in the diluted working solution.
Water is the safest chemical to use for cleaning.
Unfortunately, water only removes a limited number of contaminants from floors and other hard surfaces.
In these instances, chemicals are added to water to improve cleaning results.
Some common cleaning chemicals were developed by chemical companies for industrial applications where the risk of exposure is minimized by localized ventilation.
These chemicals, however, are less than ideal for cleaning hospitals, schools and universities or other areas where effective ventilation is not available.
To remedy this situation, new companies have started to act as independent third parties to certify formulations and ensure that they comply with minimal product safety standards.
Newer industry standards have been established to prevent the use of certain hazardous chemicals.
While these measures are very helpful, they do not completely solve the problem.
Third-party certified cleaning products may contain hazardous ingredients with U.S. Occupational Safety and Health Administration (OSHA) permitted exposure levels in the range of 1-10 parts per million (ppm), indicating a high degree of hazard.
Use of these highly hazardous products in buildings with less than ideal ventilation can create unacceptable potential exposure risks
This notion will be illustrated later.
There are products — such as heavy-duty cleaners and degreasers or floor finish removers — that have been certified, but are not "safe" for use.
These chemistries have been in use for decades because they work quickly and effectively — but not safely.
New products — greener alternatives — are available for these difficult applications with greatly reduced risks to users, building occupants and the environment.
They may take longer to work in some instances, but they are safer and their effectiveness is comparable.
Adjustments in the floor finish to accommodate a safer remover can be made to help with the transition while new, improved products are developed.
The following method will help a concerned facility manager or BSC compare one cleaning chemical to another for their relative safety in use.
Product Risk Assessment
Select a product
Identify the hazardous components from product''s Material Safety Data Sheet (MSDS) — refer to the concentrated version of a product, rather than its ready-to-use (RTU) dilution
Obtain the MSDS for each hazardous component
Complete the Component Risk Assessment Template for each component: See Table 1
Combine the Risk Assessment scores for each component to determine the risk for the product: See Table 2.
The complete Component Risk Assessment Template has more than 140 line items in numerous categories; Table 1 lists only a few examples of these.
If a hazardous component is reported to cause irritation on its MSDS, the potential score is one.
In the example above, benzyl alcohol is not an irritant, but ethanolamine is.
Both chemicals have been shown to cause difficulty in breathing; since this is a more severe effect, the potential score is higher at four.
For those chemicals where OSHA or the American Conference of Industrial Hygienists (ACGIH) has assigned permitted exposure levels, a lower level indicates the risk is greater and the score increases.
Both benzyl alcohol and ethanolamine have PELs in the 1-10 ppm range and are scored as 10.
When the template has been completed, a component total is calculated and transferred to the Product Risk Assessment Template.
The Product Risk Assessment Template summarizes the results of the component assessments by combining the individual results for each hazardous component.
A product with four hazardous components will usually score higher than another with only one or two, but the relative hazard risk of the components makes that determination.
Potential Exposure Assessment
If none of the listed hazardous components have PELs, this step is not necessary.
Identify the maximum potential concentration from product MSDS
Identify the specific gravity (SG) or density for the product
Calculate the component concentrations
If the product is a concentrate, calculate the component concentrations at working strength
Estimate product usage
Calculate quantities of hazardous components being released for potential exposure
Compare to PELs.
In addition to how and where it is used, the risk of potential exposure is as important as the hazard of a chemical.
Table 3 demonstrates how two components of a hypothetical product can create hazardous exposure in the workplace.
Multiplying the maximum concentration of benzyl alcohol — at a 25 percent concentration — times the SG of the product (1.076) times 1,000 grams per liter establishes 269 ppm per milliliter (ml) as the concentration in the concentrate.
Note: 1 gram per liter = 1 milligram (mg) per ml = 1 ppm.
Since the product is used at 20 percent by volume, the benzyl alcohol concentration in the working solution is 54 ppm.
If a worker used approximately 1 pint — or 500 mls — in 15 minutes, the amount of benzyl alcohol released to the environment is 500 times 54, divided by 15 minutes — or 1,800 ppm per minute.
With a maximum OSHA permitted exposure level of 10 ppm, this is going to be an unacceptable potential risk.
That fact, coupled with laboratory studies by A. Bello, et al — published in Environmental Health in March of 2009 — showing that it takes approximately 1-2 hours for the quality of air in a bathroom or patient''s room to return to background level after the use of chemicals for cleaning, amplifies the potential risk of exposure.
A more complex method would introduce vapor pressure to the analysis to more closely approximate the expected chemical concentrations in the air.
Greener Chemistry Associates LLC was started by Jack Fellman in early 2008 to help companies understand the principles of green chemistry, identify greener alternatives to chemicals used in the workplace and reduce shipments of hazardous waste through recycling laboratory and cleaning chemicals onsite by distillation. Greener Chemistry Associates is affiliated with Amsan, a leading supplier of janitorial and cleaning products. For more information about Risk Assessment Templates, Amsan and distillation, please contact Jack Fellman at JFellman@GreenerChemistryLLC.com or by calling 603-487-2235.