When a home, building or structure incurs damage as a result of a significant water event, the effects can be harrowing. Nevertheless, out of all of the possible negative outcomes, one of the most dangerous is the growth of microorganisms. 

Often the cause of sudden illness, respiratory complications, allergic reactions and more, the uncontrolled growth of assorted fungi and bacteria can result in unwanted physical symptoms, and sometimes, even death. 

For these reasons, it can, at times, be necessary to apply antimicrobial or biocidal agents to water affected areas to return a building or structure to a clean, safe and healthy environment, once again.

Microorganisms and Water Damage

Microorganisms are diminutive life forms that manifest themselves in the form of fungi, bacteria, parasites, algae, protozoa and viruses. They exist to digest and disintegrate organic substances into simpler compounds. As they go about this process, gasses are emitted into the air resulting in off-putting odors that often permeate a structure. 

As time goes on, these odors, often referred to as microbial volatile organic compounds, or MVOCs, become stronger, while other potentially dangerous byproducts are also released into the air. 

Eventually, this activity becomes visible, even to the naked eye, as physical staining on walls and surfaces begin to appear. 

Of additional concern is the emission of mycotoxins, highly toxic and detrimental chemicals, released by microbes in an attempt to protect their organic food source. These toxins are vastly dangerous and can prove fatal to humans and animals. 

For these reasons, it is crucial that wet surfaces and materials be hurriedly addressed following a significant water event, as neglecting to do so can lead to the multiplication of microorganisms and a whole host of negative, unsafe and unsanitary effects.

It is important to note that in order for water-induced microbial growth to occur, the following four elements are needed: 

  • A Dark Area
  • Little to No Airflow
  • Food Source in the Form of Organic Compounds
  • Spores

Once any of these four elements are removed, further microbial growth cannot start, nor can it continue. This further establishes the importance of immediate and professional restorative action. 

Some of the most common types of microbial activity resulting in the aftermath of water events include:

Fungi/Mold– Even in situations where clean water was involved, the threat of fungi still stands. In fact, fungus growth is one of the most apparent microorganism activities in water events involving the ongoing and prolonged exposure of sanitary water. 

Surface Molds– This type of microbial growth can develop on nearly any surface, as bacteria and fungi slowly begin to digest the natural compounds covering the surface. These situations don’t typically involve damage to the material itself. 

Dry Rot– At 20-29% moisture content, wood might begin to incur damage not readily seen by the naked eye. In this case, the wood affected may look dry, though its internal structural content has been afflicted. 

Wet Rot– At 30% or more moisture content, the wood will look saturated and will incur internal damage at a rapid rate.

The Use of Biocides and Antimicrobial Agents

With all of this in mind, there are times when it becomes absolutely necessary to enlist the help of chemical agents to stifle the advancement of microorganism growth. 

While the most ideal and effective way of dealing with water damage is always to rid the environment of excess moisture through the use of effectual drying techniques, chemical treatment can be also needed to ensure that the threat of fungi, bacterium and the like are fully terminated. Biocides and antimicrobial agents assist in achieving these goals. 

There are three types of biocidal and antimicrobial techniques that may be employed by a water remediation specialist to rid your environment of microbes.

The first is sanitizer. Sanitizer works to slow microbial activity, but it does not put an end to all spores and bacteria. 

Second is disinfectant, which works to eliminate microorganisms, though microbial spores often remain. 

Third is sterilizer, which is the most potent of the three, as it works to obliterate both spores and microorganisms. 


Because of the strength, potency and effectiveness of biocidal treatments and antimicrobial agents, it is recommended that clients not be present during the application of such products. In most cases, clients will be asked to vacate the premises for an amount of time set forth by a water remediation technician until the said treatment is fully complete.

This is especially important for those of special interest, including the elderly, pregnant women, children, chemotherapy-treated individuals, those with compromised immune systems and individuals who have undergone recent surgery. 

Before application of biocidal treatments, the client can expect their water remediation specialist to expound on the following:

  • The type of treatment to be used
  • The amount of time the property is to be vacated
  • Why the treatment is to be applied

The client should also expect to sign a consent form and may choose to request a copy of the safety data sheet, otherwise known as SDS. 

Bear in mind that a water restorer is also responsible for protecting him or herself from any harm. Clients should expect restorers to take to the task of resolving microbial activity using personal protective equipment, regardless of whether or not the situation seems “that bad”. 

No matter the circumstance, restorers must always use the utmost caution when entering areas that potentially have been heavily affected by microbes.

Extreme Situations

There are some situations that will need to involve the assistance of outside help. These circumstances often involve persons of special interest mentioned earlier, or facilities containing a high number of special interest groups including daycares, nursing homes and doctor’s offices. 

In these cases, Indoor Environmental Professionals, or IEPs, will be recruited to evaluate the water affected structure at hand. They will make determinations as to the overall safety of the environment, assess the damage, and uncover any potential health hazards. 

Please note that if the water event in question ever becomes designated as a Category 3 water loss, a third party, such as an IEP, will always need to be utilized. 

Professional Handling of Microbial Activity

Water events can evoke plenty of stress on their own, but with the addition of microbial growth, these types of situations can spiral out of control, fast. However, with the skillful, cautionary, and competent use of antimicrobial and biocidal agents when necessary, many of the woes associated with microbial growth can be eliminated. 

As always, be sure to reach out to a water remediation specialist for any ensuing water event as soon as possible to hinder the advancement of dangerous microbial activity.