What’s the big deal about Raised Buildings & Creosote Degraded IAQ? Growing up on the Jersey Shore back in the ’60s and 70’s we were all very familiar with that slick-black tar-like substance that never dried and stained our clothes, was impossible to get off your skin and ruined many a carpet or upholstered family chair. It was a simple fact-of-life that working or playing around waterfront docks and bulkheads and you were going to get it on you. Over the years, homeowners raised buildings & creosote and converted the area under the home into usable space which often trapped the creosote aroma emitted by the pilings and forced it up into the home. We’ve often heard it referred to as “that shore smell”.
There has been a lot of discussion and science surrounding creosote since then. And one thing is for sure, it isn’t something you want to be touching, let alone breathing in your home.
What Is Creosote?
Creosote along the jersey shore was on everything from waterfront bulkheads and infrastructure to pilings and landscape ties. Pictured here are creosote dipped floor joists in the crawl space of an older home. © victor j. Coppola
The types of Creosotes are numerous where those prepared from coal tar are the most common. Coal tar creosote is a thick, oily liquid that is typically amber to black in color. It is easily set on fire and does not dissolve easily in water. It is a restricted-use pesticide and has been deemed a “Hazardous Waste.”
What Chemicals Makeup Creosote?
The major chemicals that can cause harmful health effects are polycyclic aromatic hydrocarbons (PAHs), phenol, and cresols. Coal tar pitch volatiles varies depending on the makeup of the coal tar product that is being heated where some 300 chemicals have been identified, but as many as 10,000 other chemicals may be in this mixture many of which are known carcinogens.
Creosote Doesn’t Bother Me
Don’t let the widespread use of this compound fool you. It’s not naturally occurring in the environment and is some nasty stuff. Decades later this compound can still cause intense odors to permeate throughout a home. Permissible Exposure Limits (PEL) have been set at 0.2 mg of coal tar pitch volatiles per cubic meter of air (0.2 mg/m³) in workroom air during an 8-hour shift. No residential standards have been set which does not mean it’s ok in a residential setting.
I’ve Got This Great Encapsulant
There are many coatings that claim good success with the encapsulation of creosote. But in reality, creosote encapsulation usually fails due to bad prep, moisture, temperature, back-drafting, or just missing some creosote during the encapsulation process. Let’s face it, how can you encapsulate all the creosote if part of the piling is hidden inside a wall. We hear it all the time on newly remodeled homes that the creosote is encapsulated behind the new walls. While that may work for asbestos or lead concerns, creosote emits Volatile Organic Compounds (VOCs) that will break free from the dead air space in-time. Best to avoid it altogether.
Typical Health Effects From Creosote
Reports indicate that brief exposure to large amounts of creosote may result in a rash or severe skin irritation, eye burns, convulsions, mental confusion, kidney/liver problems, unconsciousness, or even death. Longer exposure to lower levels of volatiles by direct contact with the skin or by exposure to the vapors can result in sunlight sensitivity, cornea, and skin damage (reddening, blistering, or peeling). The International Agency for Research on Cancer (IARC) has determined that creosote is carcinogenic. EPA has determined that it is a probable human carcinogen. Or check out the Agency for Toxic Substances for even more details.
Want More Creosote Information?
Still not sure about the impacts creosote could have on the home you are looking to buy. Looking for more information, then you might want to check with the regulatory experts or talk to a Building Biologist from GreenWorks.
