Cured-in-Place-Pipe (CIPP): Inhalation and Dermal Exposure Risks Associated with Sanitary Sewer, Storm Sewer, and Drinking Water Pipe Repairs

Posted on by Andrew J. Whelton, PhD; Jonathan Shannahan, PhD; Brandon E. Boor, PhD; John A. Howarter, PhD; Jeffrey P. Youngblood, PhD; and Chad T. Jafvert, PhD.


Cured-in-place-pipe (CIPP) is the most popular water pipe repair method used in the U.S. for sanitary sewer, storm sewer, and is increasingly being used for drinking water pipe repairs. Today, approximately 50% of all damaged pipes are being repaired using CIPP technology. The CIPP procedure involves the chemical manufacture of a new plastic pipe called a CIPP inside a damaged water pipe. Before CIPP installation, workers precut and lay-up the felt and fiberglass liner and saturate it with a polyester, vinyl ester, or epoxy resin. The resin is sometimes mixed by hand or using an automated mechanical mixer, manually poured or drawn into the precut liner. Liners are then passed through rollers to ensure that the fibers are saturated with resin. The resin impregnated liner (referred to as an uncured resin tube) is typically refrigerated until use, as it may contain volatile and semi-volatile organic compounds (VOCs, SVOCs) and thermally sensitive chemicals. This uncured resin tube is often pulled through the damaged water pipe or inserted into the damaged water pipe and inflated using forced air or water. During the installation process, the curing is facilitated by periodically forcing steam into one end of the resin tube, recirculating hot water, and/or passing an ultraviolet (UV) light train through the tube. Plastic coatings are sometimes included inside and outside of the uncured resin tube for a variety of reasons. Once the facilitated curing process has ended, the hardened ends of the CIPP are cut and removed. Connections to pipe laterals are reinstated by cutting holes into the pipe walls. A reported advantage of this in-situ repair process is the avoidance of roadway shutdowns and open-trench excavations to remove the damaged pipe. The CIPP process is also being used to repair pipes in buildings.

Little is known about CIPP worker exposures and health risks. CIPP manufacturing sites are highly transient, with a single installation location being used from a few hours to a few days. Unlike traditional manufacturing operations, there is not a ‘permanent address’ to visit or inspect. Once the construction process is complete, the workers and equipment move on. The CIPP manufacturing process can expose workers to raw chemicals, forced air, steam, hot water, ultraviolet (UV) light, materials created and released into the air during manufacture, as well as liquids and solids generated by the process and worker activities. To date, CIPP air monitoring studies have been unable to comprehensively characterize occupational exposures because of a narrow focus on VOC vapors and the use of nonspecific detectors.  See below for information on the October 5th free webinar “Public Health Implications and Occupational Exposures during Water Pipe Repair Activities” (to view webinar, click here ).


New Research on Health Hazards

Image shows the multi-phase mixture that was emitted into the air by a steam cured CIPP installation at its exhaust emission point. This mixture contained particulates, droplets, partially cured resin, organic vapors, and water vapor.

A new peer-reviewed study published in the journal Environmental Science and Technology Letters found that during steam-cured CIPP installations, many different types of materials were created and released into the air. These materials included particulates, droplets, partially cured resin, organic vapors, and water vapor. While historically referred to as “steam” (and thus implying only water vapor), the emission instead is a “multi-phase mixture” or emission cloud. A variety of VOCs and SVOCs were measured in the emission cloud and included suspected carcinogens, hazardous air pollutants, suspected endocrine disrupting compounds, and other unidentified compounds. Some included acetophenone, benzaldehyde, benzoic acid, butylated hydroxytoluene (BHT), 4-tert-butylcyclohexanol, 4-tert-butylcyclohexanone, dibutyl phthalate (DBP), phenol, styrene, and 1-tetradecanol, among others. Because common equipment can be used by a contractor for a variety of resin compositions, chemical cross-contamination is also possible. For example, one CIPP installation that was measured featured a non-styrene based resin. However, styrene was emitted from this installation, notably at a much lower concentration than the styrene-based resins. This finding indicated contractors likely accidentally contaminated their equipment with a previous styrene-based compound. As such, contractor equipment handling and cleaning practices between CIPP installations should be further studied. Emissions from the CIPP sites tested were transient, varying second-by-second and exhibiting extreme spikes in chemical concentration. This concentration variation was influenced by environmental and meteorological conditions, worksite activities, and differed between CIPP installations even when the resin, pipe size, and contractor were the same.

Image of a worker without respiratory protection inspecting a CIPP emission point at a sanitary sewer pipe manhole.

Results of the new study suggest the importance of both inhalation and dermal exposure routes. No organic vapor respiratory protection was observed for workers during CIPP installations reported in our study. Workers were in chemical plumes and inhaled the chemical-laden air. Their skin and clothing were exposed. Some CIPP workers handled the uncured resin tube with their bare hands. Others were exposed to liquid-like materials during insertion of the uncured resin tube and curing. The multi-phase mixture emitted into the air was collected and tested to see if it was toxic to mouse cells. Tests indicated that samples collected from 2 of 4 CIPP sites were cytotoxic (caused cell death). Non-styrene compounds appeared responsible.

The new study also cited 59 CIPP air contamination incidents. Incidents involved public complaints of illness, building evacuations, emergency service personnel responses, and in many cases these incidents were reported in the popular press. Since the new study was published, several chemical incidents associated with CIPP sewer repairs have occurred in Nyack, NY, Dublin, CA, Lee’s Summit, MO, Beaver, PA, and San Diego, CA all reported in local media outlets. These exposure reports primarily originated from the general public who were not associated with the installation work being performed. The California Department of Public Health also issued a CIPP safety alert based on their own investigation.

While different types of materials are created and emitted into air during CIPP installations, the distance the materials travel from the worksite emission points, extent of spatial and temporal variations in material concentrations, and whether or not they are transformed into more or less toxic materials in the air is currently unknown. Different work tasks and a wide array of site, environmental, and pipe conditions, resins, manufacturing processes, and other variables should be considered in documenting occupational health risks. Also lacking is an understanding of what materials are emitted from hot water- and UV-cured CIPP sites. Compound- and phase-specific intakes, doses, and any associated acute and chronic health effects among workers must be determined. Because methods commonly used for air sampling and for industrial process monitoring only capture vapors, additional air sampling procedures are needed. These procedures should help understand occupational exposures and potential health risks when particulates and semi-cured compounds may also be present in the air.

Next Steps

The new study identifies concerns about potential health risks to CIPP workers and underscores a need for additional investigation. Occupational risks for municipal and consulting engineer employees, separate from CIPP companies, who visit and supervise CIPP job sites, should be investigated. Also needed is an understanding of public health risks for persons nearby. Until more is known about the exposures generated by CIPP and the health implications for workers, the authors recommended that inhalational and dermal exposures be minimized through a combination of engineering and administrative controls and the use of appropriate personal protective equipment. The authors also recommended exposure monitoring of the multi-phase emissions to ensure the emissions are being captured.

The study authors at Purdue University and workplace safety experts at the National Institute of Safety and Health (NIOSH) are seeking partners for future studies. Persons who install CIPP, visit, and supervise CIPP sites can request health hazard evaluations from NIOSH. Test results are being sought for the emission points and worker exposure monitoring from those organizations that have conducted prior air testing. This may include CIPP companies, consulting companies, local, county, state, and federal agencies, private and public utilities, and insurance companies, among other organizations.

For more information on the new peer-reviewed study Worksite Chemical Air Emissions and Worker Exposure during Sanitary Sewer and Stormwater Pipe Rehabilitation Using Cured-in-Place-Pipe (CIPP) visit the website or   The scientific report, supporting Information file and video files can be downloaded free of charge.


The National Environmental Health Association is hosting a free webinar on October 5th from 3-4 EST “Public Health Implications and Occupational Exposures during Water Pipe Repair Activities”.  Speakers from NIOSH and Purdue University will present information to help local, state, and county health professionals better understand public health and occupational exposures with cured-in-place-pipe.

To view the webinar click here .


Andrew J. Whelton, PhD, is an assistant professor in the Lyles School of Civil Engineering and Division of Environmental and Ecological Engineering at Purdue University.

Jonathan Shannahan, PhD, is an assistant professor in the School of Health Sciences at Purdue University.

Brandon E. Boor, PhD, is an assistant professor in the Lyles School of Civil Engineering at Purdue University.

John A. Howarter, PhD, is an assistant professor in the School of Materials Engineering and Division of Environmental and Ecological Engineering at Purdue University.

Jeffrey P. Youngblood, PhD, is a professor in the School of Materials Engineering at Purdue University.

Chad T. Jafvert, PhD, is a professor of civil engineering in the Lyles School of Civil Engineering and Division of Environmental and Ecological Engineering at Purdue University.

This work was funded by the U.S. National Science Foundation RAPID Grant CBET-1624183, Purdue University, and crowdfunding.


Posted on by Andrew J. Whelton, PhD; Jonathan Shannahan, PhD; Brandon E. Boor, PhD; John A. Howarter, PhD; Jeffrey P. Youngblood, PhD; and Chad T. Jafvert, PhD.

29 comments on “Cured-in-Place-Pipe (CIPP): Inhalation and Dermal Exposure Risks Associated with Sanitary Sewer, Storm Sewer, and Drinking Water Pipe Repairs”

Comments listed below are posted by individuals not associated with CDC, unless otherwise stated. These comments do not represent the official views of CDC, and CDC does not guarantee that any information posted by individuals on this site is correct, and disclaims any liability for any loss or damage resulting from reliance on any such information. Read more about our comment policy ».

    I love how simple yet informative this page is in giving the crucial information. Thanks for sharing the valuable information…Your writing style has been amazed me. very great post.
    Sewer Repair Lookout Mountain

    I’m sure glad you’re studying this and working on if from the workers safety point of view.
    That’s some nasty stuff. But, holy smokes, can you imagine being contaminated by that stuff.

    Glad you’re on it.

    Wonderful post, health hazards should be taken care of and the necessary precautions should be taken care of. There are many health risks that people engaged in this industry have to relate with. Keep sharing this post more and more.

    Great article. Truly the industry is expanding rapidly in New Jersey and around the country and so are the safety concerns. Still CIPP is one of the best systems that have been used by [name removed]in this industry. The failure rate is less than 5% if properly installed and supervised. With other options like pipe coating offered at companies like [name removed] east coast clients can save even more money and expense when multiple laterals are involved too. Either way we hope this CIPP system will be around for a long time.

    I’m sure glad you’re studying this and working on if from the workers safety point of view.Wonderful post, health hazards should be taken care of and the necessary precautions should be taken care of.Superb article. It will definitely help us. thank u so much for sharing with us.
    Water Lines Lookout Mountain

    That sounds really nasty, these workers should be provided with the proper safety equipment such as high-quality respirators and chem suites if necessary. Also is this method really safe to be used to repair residential clean water pipes?


    I install cipp and we are provided respirators, tyvek suits, gloves, and other ppe. The only downfall is there are times when you need a say respirator but conditions won’t allow it.

    This system is currently being installed in my neighborhood. Thank you for your report. Our City govt officials have not notified residents that this work was being done, we have experienced fumes coming into our home, one neighbor was so alarmed by the strong odor that she called the Fire Dept. I know of 4 other neighbors who have called the City Water Dept because of these strong odors while work is being done. One City engineer told me that the gas dissipates, and is not harmful. We know the work is needed for our aging and collapsed sewer system, and are shocked that our
    City gov’t, and the subcontractor, have so far declined to notify residents of this process. I feel strongly that residents should be notified well in advance, so that we can make informed decisions about how to protect our health.
    There is a big disconnect here between the City Govt, and the subcontractor, [name removed] concerning notification of residents. 24 hr notice that you will have no water service, that you need to pour water down all the drains in your house, and, BTW, if you do experience fumes in your home, call the City, subcontractor, or both, and if needed, someone will come and help you air out your home. Obviously, this is not a benign process. I would rather the streets be torn up for a while if that is safer. I’m concerned for my neighbors whom are elderly, live alone, some in compromised health situations, and others, who work , may be out of town, and could arrive home, and not realize they need to open windows before they could potentially pass out. I am taking the time to write all this in hopes that some other City will see the need to notify residents to avert some potential tragedy. I cannot tell you how shocked and disappointed I am in my City govt’, which only has to govern about 20,000 people. And I will also tell you that I am in the autoimmune spectrum due to Heavy Metals poisoning, and that I experienced severe burning of mucous membranes, headache, joint swelling and aches when exposed to the gas, whatever it was that cam into my home. Sent me straight to my Dr. And we don’t even know exactly what I’ve been exposed to. Other neighbors have reported mouth sores in adults, and mysterious rashes in children and babies. Are you listening CDC?

    Thank you for your comment. The research we have conducted has been funded by public entities, so it is our intent for you and your community to directly benefit from it. You can visit and gain access to free/downloadable information and completed peer-reviewed scientific studies. Videos, frequently asked questions, and other information is also available. Because little information is available about the potential health risks posed by the array of chemicals emitted by this pipe repair practice, we continue to conduct additional testing. We will post new information at this website when it is available.
    If you want to learn more about the process, you may also want to watch the 2017 National Environmental Health Association ( free webinar here: This webinar was designed to help health officials gain a better understanding of the information available about the potential chemical emissions with the technology use. Your health officials may benefit from learning about new test results and recommendations associated with this practice.
    It is not uncommon that persons at and associated with municipalities are unaware of the chemicals and potential health risks associated with the pipe repair practice. There has been very limited testing data available.
    In terms of what you can do, you may want to contact your state health department and request assistance. Your state health department (industrial hygienists, toxicologists, epidemiologists, medical doctors, etc.) may be able to directly engage your community or facilitate assistance. Your state health department may also be able to engage the CDC for assistance. You can also connect your health officials with our website, our contact information, and the National Environmental Health Association. There are a growing number of health professionals seeking to learn about this practice so that they can best advise their communities and prevent any harm from occurring.

    Thank you for your comment. We are sorry to hear about what you have experienced. Please see the response from our Purdue colleagues on resources for more information. We are with NIOSH, the part of CDC focused on making workers safer and healthier. We posted this blog to raise awareness about this new technology and ways to experience its benefits but avoid potential risks to workers.
    Since your concerns are for residential as opposed to occupational exposures, you may wish to contact your state health department. The web site for the Virginia Department of Health, Division of Environmental Epidemiology is at this address: Contact information is available on the web site. In addition, Virginia has a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR), a part of CDC that works to address environmental public health issues ( Information about the cooperative agreement is posted on the web at

    As a worker that installs cipp we aren’t supposed to talk to the homeowner. That is the cities job. Now especially post covid we can not go up to peoples houses. You can use water while we do this. You should just limit it because your lateral lines will be blocked until the liner is cured. For example I wouldn’t do laundry or run excessive amounts of water. As for the smell entering your home if you flush your toilets and run a little water it will create a barrier and fumes wont travel up the pipe.

    This research in health hazards is indeed a good source for us as a sewer repair company with the aim of providing quality service to the people in Phoenix

    what a great article. it’s very instructive and well informed.
    Thanks for sharing with us. it will definitely help us. well done. keep sharing.

    I brought this issue with styrene up with Denver’s Metro Wastewater Reclamation District, now Metro Water Recovery, 15 years ago. They thought that I didn’t know what I was talking about.

    Hi, I am concerned by the finding that workers may be exposed to hazardous chemicals and that these risks are not yet fully understood.

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Page last reviewed: December 13, 2017
Page last updated: December 13, 2017