The Chemistry of Safety + Effectiveness for Cleaning and Disinfecting Facilities

Manufacturing plant managers and engineers have never faced a challenge a great as controlling the virus that causes COVID-19. However, another workplace risk looms beyond virus exposure: the use and overuse of some dangerous disinfectants. Understanding the chemistry of both safety and effectiveness is essential for developing and implementing a cleaning and disinfecting protocol.

Plans to re-open plants—and keep them open—must include safeguarding custodial staff and those tasked with cleaning and disinfecting. Not only are they at increased risk of virus exposure, but they are also subject to any toxic effects of cleaning chemicals. The Centers for Disease Control (CDC) urges managers to ensure that staff wear appropriate PPE for cleaning and disinfecting and be instructed on how to use cleaners and disinfectants according to the label.

The (CDC) has also conducted a study on the increased toxic chemical exposure risks due to the increased use of disinfectants. These risks mount exponentially based on the size of the facilities and the number of employees. This study highlights the responsibility of manufacturing facility managers and plant engineers to become informed about the best disinfectants to use for each particular application and to prevent harmful exposures to the workforce and end-user. Selecting the right product, using it correctly, and storing it safely after use should be the main objectives when fighting the invisible pathogens around us.

The United States Department of Labor Occupation and Safety Health Administration (OSHA) is very clear in its Hazard Communications standard (1910.1200):

In order to ensure chemical safety in the workplace, information about the identities and hazards of the chemicals must be available and understandable to workers. OSHA's Hazard Communication Standard (HCS) requires the development and dissemination of such information:

• Chemical manufacturers and importers are required to evaluate the hazards of the chemicals they produce or import, and prepare labels and safety data sheets to convey the hazard information to their downstream customers;
• All employers with hazardous chemicals in their workplaces must have labels and safety data sheets for their exposed workers, and train them to handle the chemicals appropriately.

OSHA issued its standard to address comprehensively the issue of classifying the potential hazards of chemicals, communicating information concerning hazards and appropriate protective measures to employees, and to preempt any legislative or regulatory enactments of a state, or political subdivision of a state, pertaining to this subject.

The scope of OSHA provisions for developing and maintaining a written hazard communication program for the cleaning and disinfecting products used in the workplace is comprehensive. They include lists of the hazardous chemicals present, preparation and distribution of the OSHA-required safety data sheets to employees, and development and implementation of employee training programs regarding hazards of chemicals and protective measures.

While safety is paramount, simultaneously ensuring the effectiveness of cleaning and disinfecting protocols is essential when combatting the massive threat of COVID-19. Striking a balance between safe and effective seems complex, but by drawing on basic chemical knowledge, the decision of what to use, how much, and when is simplified.

The first rule in a facility of any size or type is to always use disinfectant products in accordance with label instructions and store the products safely. Selecting the right product for the job involves understanding a bit of the chemistry of both the biocide (germ killer) in the product as well as the surfaces to be treated. 

CHEMISTRY OF EFFECTIVENESS

Biocides are found in all disinfectants. Most act by disrupting the cell membranes of the organism to be killed, such as viruses and bacteria. Some, like bleaches (hypochlorite or peroxide for instance) literally oxidize and burn through the cell walls, destroying the organisms in the process. This is a very aggressive approach and is highly effective on hard, colorfast surfaces that are not damaged by bleaches. 

However, bleaches can be very harmful to porous surfaces such as fabrics, carpets, and even human skin. Anyone who has accidentally bleached a load of brightly colored clothes into oblivion can attest to the effectiveness of bleach when it comes to destroying the colored fabric. 

Another type of disinfectant are quaternary ammonium compounds (“quats”) and alcohol-based disinfectants also are also commonly used to control harmful bacteria and viruses. Each has its own advantages and disadvantages. Examples of quaternary ammonium compounds include benzalkonium chloride, alkyl dimethyl benzyl ammonium chlorides, and alkyl dimethyl ethyl benzyl ammonium chloride. 

While alcohol disinfectants can be effective, the alcohol evaporates very quickly, limiting its effectiveness. In general, disinfectants must stay wet to remain active on the surface so alcohols that evaporate quickly are generally less effective than water-based disinfectants that take longer to evaporate from a surface.

To complicate matters further, the level of effectiveness is based on the dwell time of the chemical on the surface. There is a common misconception that using a spray and wipe technique will clean and disinfect. The ability to train maintenance staff and enforce protocols adds yet another consideration for facilities professionals–one that can have negative effects on those tasked with applying chemicals.

CHEMISTRY OF SAFETY

There are dual focuses when weighing the safety of any particular disinfectant: safety-from applicator standpoint and safety-from employee standpoint. 

All bleaches are harmful or fatal if swallowed and can cause serious and sometimes permanent burns if splashed on the skin or permanent blindness if splashed in the eyes.

Hypochlorite bleaches are generally caustic and corrosive and must be handled with care and never mixed with other cleaners or chemicals of any kind. Only clean water can be used to dilute bleaches for disinfectant use, otherwise dangerous reactions can occur, liberating chemicals such as toxic chlorine gas. 

It is the chlorine gas liberated on contact with surfaces that kills organisms, but it is also this chlorine gas that can pose a real exposure hazard for the user. When chlorine is inhaled, it attacks the cells lining the lungs and destroys them in the same way it kills mold, bacteria, and viruses. The damaged cells in the lungs die and release fluid causing what doctors call chemical pneumonia. This is always harmful and if the exposure is severe enough, it can prove fatal. There are studies that indicate that even low exposure to cleaning products over a long period of time can negatively impact lung function similar to the damage done by smoking. 

Quats have long been known for their eye, lung, and skin irritancy hazards and can be harmful if swallowed, cause eye and skin burns, and are harmful if inhaled. Quats are also very toxic to aquatic life.  This latter point is particularly important when disposing of unused disinfectant down drains and thereby into the municipal water treatment systems.

Interestingly, in the United States, quats are often used in cleaners with few if any health warnings, while in the European Union, quats are considered hazardous pesticides and are heavily regulated. This is due, in part, to concerns that quat overuse may lead to the development of resistant bacteria or “superbugs.”

CHEMISTRY OF SAFETY + EFFECTIVENESS

In comparison to bleaches and quats, botanical solutions exist in the marketplace that are both safe and effective. Bioesque for example is a widely used mild water solution of neutral pH with no eye or skin hazards. Its active ingredient thymol is a natural monoterpenoid phenol, found in oil of thyme, and extracted from Thymus vulgaris (common thyme). Thymol is low in toxicity to humans, animals, and the environment. 

For some of these products no rinsing is required after use, so they are suited for use in restaurants, grocery stores, and food processing facilities where food is prepared or stored. 

To apply these botanical solutions, personal protective equipment is required to avoid exposure to pathogenic bacteria and viruses within the treatment area, not due to the product itself. When searching for a botanical product, look for NSF and EPA- registered products certified as antimicrobial.

Botanical disinfectants that are classified by the United States Environmental Protection Agency (EPA) as “Category IV” means that no signal words, no precautionary statements, and no first aid statements are required on the label. They are also readily biodegradable, posing no immediate or long-term risk to humans or the environment. Further, they are not regulated as dangerous goods by either US DOT or IATA for shipping purposes, nor subject to the reporting requirement of California Proposition 65, which lists chemicals that cause cancer or reproductive harm.

When it comes to effects on hard or porous surfaces, the EPA has approved certain botanical disinfectants for disinfection of hard, non-porous surfaces such as metal, rubber, painted or varnished surfaces, glazed ceramic, glazed porcelain, glazed tile, and glazed enameled surfaces, glass, sealed or varnished wood, sealed marble, steel, stainless steel, chrome, brass, aluminum, sealed concrete, sealed fiberglass and many plastics including polypropylene, polystyrene, polyethylene, polycarbonate, and PVC. 

In the case of Bioseque, it has been tested and approved by Boeing for use on hard and soft surfaces aboard aircraft for this reason. It is currently being used by automotive OEMs as well. It is also approved by the EPA for sanitization of soft surfaces including home textiles, upholstery, mattresses, bedding, apparel fabrics, fabric sided luggage, and rugs.

In the pandemic and beyond, plant managers and engineers will be tasked to select the right disinfectant for the area to be treated and understand how to use it and store it safely. Not only will it be a permanent clause in OSHA standards, but it will make the difference in protecting the workforce from both harmful bacteria and viruses and the effects of the disinfectants themselves.

Dr. Larry Beaver is Vice President of Research & Development for Clean Safely, a curated platform that helps businesses and industry clean, disinfect, and maintain their premises. Clean Safely was recently introduced by RSC Bio Solutions, a 30-year leader in producing readily biodegradable products for both land and marine applications. Dr. Beaver also oversees R&D and regulatory functions for all RSC Bio Solutions products, including EnviroLogic® and FUTERRA™.