A construction worker in a gray uniform is applying a vapor intrusion barrier system on site.


There are many different safety concerns when carrying out development or renovation projects. One vital but often overlooked factor is that of vapor intrusion. Vapor intrusion is often invisible and difficult to detect, yet can cause all manner of health, safety and environmental issues.

When planning a construction or renovation project over soil that might be environmentally impacted, you want to be knowledgeable enough to make sure that problems such as vapor intrusion are addressed and prevented. Failing to do so can cause serious health issues and impact the value of the structure. Unfortunately, balancing all of the different factors involved with a project can be difficult or impossible.

Working with experts can help you to address issues and make sure that projects are safe, both now and in the future. Environmental consultants can carry out exhaustive vapor intrusion testing and screening to set your mind at ease and allow you to know that your project is safe.

What is Vapor Intrusion?

The term ‘vapor intrusion’ refers to when vapor-forming chemicals enter a building through surfaces such as floors or basement walls. In almost all cases, vapor intrusion happens as a result of inadequate building envelope protection. While some vapors may be harmless, more dangerous contaminants can often enter buildings.

Contaminant vapor intrusion can seriously impact indoor air quality. Contaminants include volatile organic compounds (or VOCs) like benzene, methane and trichloroethylene (PCE) and are often found in soil as a result of pollution or other industrial contamination.

Vapor Intrusion Testing and Screening

This job site features an EPRO waterproofing solution. There is a large commercial building in the far left corner of the picture.


Vapor intrusion testing involves collecting samples of gasses from the soil on a building site, or even the adjacent property. The screening process then involves analyzing the samples to determine whether or not the site concentrations are safe for occupants of the new structure and what kind of vapor intrusion mitigation solutions may be required.

Testing typically entails the drilling of holes into the ground below a building (known as sub-slab vapor sampling) and the extraction of any gasses from the soil via a sealed vacuum cylinder or summa canister. This usually takes place over the course of several hours to one day. Testing usually occurs when contaminant vapor intrusion is suspected due to previous site investigations, chemical odors would be the obvious sign that a VI issue is present.

The screening process happens once the samples have been extracted, and it involves comparing levels of chemicals to reference levels. A VISL (Vapor Intrusion Screening Level) calculator was developed by the EPA to help screen sites for potentially harmful chemicals entering structures. If high levels of volatile and/or toxic contaminants are found, the EPA may conduct an investigation of how the soil may have become contaminated.

The VISL calculator provides screening-level concentrations for groundwater, near-source soil gasses, sub-slab soil gasses and indoor air. They are based on complex metrics including exposure scenarios, a target cancer risk level of one in a million and a target non-cancer-related hazard quotient of 0.1.

The parameters provided by the EPA’s VISL calculator are defaults, but they should be altered to reflect more site-specific scenarios if needed. For example, acceptable concentrations can differ based on whether projects are residential or not. For more detailed information on how the calculator works, check out the EPA website.

Why are Vapor Intrusion Testing and Screening So Important?

Vapor intrusion can cause all sorts of serious problems, from health issues to structural building damage. Minor health concerns for building occupants include headaches, nausea and irritation of the eyes, skin or throat.

In more serious cases, contaminant vapors can even increase the risk of cancer — benzene and TCE are known carcinogens, and radon is the top cause of lung cancer in non-smokers. Other potential effects of exposure to harmful vapors include liver, kidney and heart damage, reproductive issues and damage to neurological and cognitive functioning. When people live and work in buildings contaminated with these vapors, they become exposed to these harmful chemicals over long periods of time.

Contaminant vapors can damage the structure of buildings. Vapors such as methane or petroleum-based chemicals are highly flammable and can dramatically increase the risks of fires or explosions.

Failing to carry out sufficient vapor intrusion testing and screening can greatly increase the chances of any of these serious issues occurring. Contractors and developers not only have a moral responsibility to take the necessary steps to protect public health, but they can also be professionally and legally liable for any issues that occur as a result of inadequate safety measures.

What to Do If Vapor Intrusion is Detected on a Site

If screening reveals the presence of contaminant vapors on a site, whether it is an existing building being renovated or the site of a planned development project, it is essential to address the problem. The most common solution is to install a vapor intrusion mitigation (or VIM) system such as a vapor intrusion membrane. Vapor intrusion membranes consist of one or more durable waterproof layers that prevent vapors from passing from the soil into building interiors. They can also be used in conjunction with vapor collection systems if conditions require this.

Choose EPRO To Help Keep Projects Safe

A construction worker on site applying a vapor intrusion barrier.


At EPRO, we have almost three decades of experience in providing durable, long-lasting waterproofing solutions for construction and renovation projects of all kinds. We understand how difficult it can be to determine and solve issues with contaminant vapor intrusion, and our experts can help you to do so — whatever the site-specific conditions of your project.

Whether your testing and screening discovers vapor intrusion in an existing project, or contamination of soil on a site where your next construction project is planned, our waterproofing solutions add a layer of protection that makes sure your project is safe. Our products utilize a water-based, spray-applied polymer-modified asphaltic emulsion and a unique method called Redundant-Field Installed Composite Design that is highly effective in a wide variety of conditions.

Our wide range of products means that we can provide solutions for various different projects, whether on brownfield or greenfield sites. Our VIM solutions ensure safety for present and future residents of sites. Our products include:

  • Geo-Seal® 100: The most chemically-resistant composite vapor intrusion barrier on the market, the Geo-Seal 100 consists of three layers — a base, a 60-millimeter core and a bond.

  • Geo-Seal EV80: An EVOH composite vapor intrusion barrier, the Geo-Seal EV80 includes an EV30 layer, a core layer and a bond layer.

  • Geo-Seal 60: The most cost-effective composite vapor intrusion barrier available, the Geo-Seal 60 also includes three durable layers.

  • Geo-Seal EV40s: A single-sheet geocomposite barrier, the Geo-Seal EV40s outperforms other single-sheet layers available and is ideal for lower-risk projects.

  • Geo-Seal EFC: A chemically-resistant VIM epoxy coating, Geo-Seal EFC is ideal for application to existing structures, particularly concrete floors.

  • Vapor-Vent™: A composite vapor collection system designed for sub-slab installation.

Choosing the ideal VIM system for your project can be very tricky, as there are usually many variables involved. However, our team of highly-qualified experts can offer advice, recommendations and support at every step of the way.

Contact Us Today

To partner with EPRO for your next commercial construction or restoration project, we’ve made the process quick and easy for you. After you fill out our form on our website, our experts will evaluate your site details and project goals. Once we’ve done a thorough review, we’ll get back to you with the best solution for both your project and budget.

Once the EPRO solution has been applied and your project has reached completion, our experts remain available to provide you with any support you may need.
Interested in working with us on your next project? Contact our team today!