What Makes A House A Biohazard?

There are different types of biohazards that you can be exposed to in a home. In some cases, the risks associated with exposure could be so serious as to result in a serious health crisis or even death. Here we will look at what kinds of materials and substances constitute a biohazard and how you should handle the situation.

It is not uncommon for people in the cleanup business to encounter biohazard situations and require information that will prevent them from coming to harm or spreading infection. Let us start by defining what a biohazard is.

What constitutes a Biohazard?

A biohazard is a biological material or substance that poses a threat to the health of a living organism, human or animal. They can come in various forms including bodily fluids, animal waste, animal infestations, laboratory waste, mold, fungus, industrial chemicals, and more.

Often it is not so much the substance but what it carries that can be hazardous. For instance, with blood, there could be bloodborne pathogens like viruses and bacteria that could cause the transmission of dangerous diseases. You will also find that certain biohazards are not considered as dangerous. This can include mucus, urine, and sweat.

Illustration of rod-shaped and spherical (cocci) bacteria. Rod-shaped bacteria include Escherichia coli, Salmonella, Shigella, Legionella, Mycobacterium, Klebsiella and other species. Spherical bacteria include Staphylococci and Streptococci species.

Some biohazards are also quite rare in the home, while others could be more common than you think. It is important to be able to identify the different types of biohazards.

To help in determining the level of risk and how it should be handled, the Centers for Disease Control (CDC) has defined four different biosafety levels in terms of the extent of harm they can cause.

  • Level 1 – These are biohazards that pose a minimal threat to human life.

These agents are considered to not generally cause disease in healthy humans. No special containment is required however precautions such as wearing gloves and a face mask should be applied.

  • Level 2 – These are biohazards that pose a moderate threat to human life.

This applies to biohazards that are not transmissible through inhalation. Though not expected to be harmful to healthy humans, they may cause infection if there is direct contact with skin that is broken or through ingestion. 

  • Level 3 – These are high-risk pathogens that may become airborne.

These pathogens have the potential to cause serious and life-threatening illnesses such as tuberculosis. They can cause infections even without direct contact.

  • Level 4 – There are life-threatening pathogens with no known vaccine, treatment, or cure

These pathogens have a high fatality rate and may be newly discovered or unresearched hence not fully understood by the scientific community. These pathogens call for the highest level of precaution including the use of full-body pressure suits with their own air supply and decontamination measures.

When there is a risk of exposure to biohazards, regular cleaning will not be sufficient in eliminating the microorganisms. Hence a need for hazardous material cleanup.

Where can exposure to biohazards occur

When people think of biohazards, their minds immediately turn to people in hazmat suits surrounding some laboratory. Movies and tv shows have done much in helping inspire such ideas. However, it is possible to become exposed to biohazards even in your home and workplace.

A simple leak can cause dangerous black mold to form or a rat infestation that compromises the air quality. Industrial premises can have dangerous chemicals that are accidentally spilled or vagrants who take illicit drugs and leave behind used needles.

Not to mention anywhere an accident or crime may occur, or a medical emergency. There are so many different situations that could play out, resulting in different kinds of biohazards being released at a location and requiring proper cleanup. Let us delve deeper into some of the more common types of situations where a house can be declared a biohazard.

What makes a house a biohazard?

  • Heavy bleeding

Some incidents can occur in the home that results in excessive bleeding and thus exposure to human bodily fluids. Situations like suicides that involve cuts or criminal acts like homicide or assault that include the use of weapons will often result in spillage of blood, saliva, urine, and other bodily fluids.

Where there is blood, there is the risk of bloodborne pathogens. These microorganisms can carry diseases that could be transmitted to humans.

Even if the scene of the accident or crime is left for a long period, it could result in harmful microorganisms breeding.

  • Medical quarantine

Certain diseases can be highly contagious and airborne but the patients have been confined to the home as we have seen during the pandemic. Even if the person is restricted to just a couple of rooms, it will turn your entire home into a biohazard. It is important to try and limit their access to the rest of the home for as long as they remain sick and contagious.

  • Animal infestations or carcasses

It is not uncommon for animals to gain entry into a home and end up dying there. Rodents like rats and mice will often do this in certain areas. Abandoned homes can also have animals like stray dogs and cats taking up residence and ending up dead inside. it also does not have to occur within the main house.

If you have a neglected tool shed on the property or a covered pool or hidden yard area where an animal can get in unnoticed, it is possible to find yourself in a biohazard situation. If the remains of the animal are not quickly noticed and removed, there is a high risk of pathogen breeding that may occur and pose a threat to human and animal life.

  • Sewage backup

If there is a blockage in your drainage system, it could result in the water and waste from your toilets, sinks, and other drains not evacuating properly. When wastewater buildup occurs, it can pose a health risk to the occupants of the house.

  • Hoarding

This is whereby a property owner or occupant does not throw anything out and ends up accumulating an unhealthy amount of possessions, whether useful or useless. This problem is often a result of mental health problems that need to be professionally addressed.

This situation often leads to a large amount of clutter that makes it impossible to keep the property clean and can even result in animals and even people getting sick and dying on the premises. Pets and rodents can easily die in such situations and due to the existing odor and dirt, go unnoticed as their carcasses decompose. Not to mention the buildup of animal and human waste that can occur.

  • Criminal activity

There are all kinds of criminal activities that can take place in residential properties. This can include violent murders and suicides that result in bloodborne pathogens. There could also be chemical spillage in homes used as meth labs or from tear gas residue released during a police raid. There is also the risk of used needles and other drug paraphernalia being left in homes occupied by drug addicts.

  • Mold or fungus infestations

Where there are water leaks, especially in hidden areas like behind walls and in casements, there runs the risk that mold or fungus infestations may take hold. When this happens, the infestations can quickly spread and compromise the air quality of the entire home.

What happens during biohazard cleanups?

As said, regular cleaning is not adequate to deal with such situations, no matter how good your deep cleaning skills are. Biohazard cleaning is something that must be meticulously undertaken to ensure not a trace of biohazardous material or microbes is left behind. When doing regular cleaning, leaving behind a speck of dust is not a big deal. However, when you have biohazard contamination, even a minor oversight can prove dangerous.

While people tend to more often associate biohazards with hospitals and laboratories, the situations described above are proof enough that the same dangers can also occur in the home. And whether it is in a hospital or the home, the same level of care and attention must be given when it comes to clean up.

The biohazard cleanup process involves the use of special equipment and cleaning products. This can include:

  • PPE gear such as airtight clothing, respirators, gloves, face shields, and goggles
  • Specialized cleaning products
  • UV light sources for sanitizing and deodorizing
  • Setting up of a control room

There is also a need to make arrangements for the disposal of hazardous material that is collected. Sometimes where the biohazardous material lands cannot be cleaned. This may require the cleaner to dispose of a part or an entire household item. This makes biohazard cleanups sometimes destructive as attempts are made to ensure the complete removal of contamination.

Control rooms are needed to create a clean environment where cleaners can enter and exit the home without risking the spread of contaminants. This setup is especially important when dealing with possible airborne pathogens or multiple pathogens at once.

Once a cleaner has all the necessary gear and is suited up, they will need to meticulously go over the entire property to ensure suitable cleaning and decontamination. They need to be very thorough, even if it means taking apart furniture, furnishings, and more. They will also need to keep testing under and around areas they are cleaning to ensure nothing is missed. UV light sources are used to decontaminate the air.

When it comes to disposal of the biohazardous material that has been collected, the cleaning company will need to abide by whatever local and state regulations are in place.

Why you should not attempt biohazard cleaning

Biohazard cleaning can be time-consuming and expensive. Hence the reason some property owners will consider doing the work themselves. However, going the DIY route can be a bad idea.

Biohazards are a risk to human health and if improperly cleaned could result in the later occupants of the property suffering illness and possibly death. Different kinds of biohazards require different types of special cleaners to effectively decontaminate and make the area safe.

Whatever helpful DIY information you might find on the internet is unlikely to be as effective as what a professional will be able to do for you. They will know how to correctly apply the cleaner and ensure it has worked effectively before moving on. They are also more thorough in ensuring that all parts of the home are sanitized before other occupants come in.

Depending on your jurisdiction, having a property that has been contaminated with biohazards and allowing people to occupy the property could be a criminal act. So can attempting to do the cleanup yourself and failing to meet regulatory standards when it comes to disposing of the biohazardous material. Note that it is illegal to dispose of biohazardous material with the regular trash. Even the trash bags used need to be appropriately labeled so that they contain biohazards. In many places, this kind of waste must be taken to a designated facility for incineration.

Professional cleaners that specialize in biohazard cleaning will not only have the necessary knowledge, equipment, and cleaning products, but they will also know where and how to safely dispose of the biohazards.


If you have a house that may require biohazard cleaning, always leave it to a professional. Trying to do this work on your own will put the lives of people and animals at risk. Whether the incident that led to the contamination was recent or years ago, you will need expert help to make the house safe and habitable for later occupation.

Given the range of incidents that can occur in a home that would lead to exposure to hazardous material, it is important to be discerning about the risks you are exposing yourself and others to. Some of these situations can even be avoided if you adhere to a regular cleaning schedule and pay attention whenever problems arise. For instance, keeping an eye and ear out for leaks and condensation can help you avoid incidents of mold and fungus growth. Getting treatment for hoarding can also help avoid that situation.

Performing a deep clean of your home at least once or twice a year can also help in identifying problems early and hopefully avoid the cost and intrusion that comes with biohazard cleaning.