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Reports and Other Documents

  • Cured-in-Place-Pipe (CIPP): Inhalation and Dermal Exposure Risks Associated with Sanitary Sewer, Storm Sewer, and Drinking Water Pipe Repairs. CDC NIOSH Science Blog. September 2017.
  • Worksite Chemical Air Emissions and Worker Exposure during Sanitary Sewer and Stormwater Pipe Rehabilitation Using Cured-in-Place-Pipe (CIPP). Environmental Science and Technology Letters. July 2017. Available at or contact us for a copy.


Chemical emissions were characterized for steam-cured cured-in-place-pipe (CIPP) installations in Indiana (sanitary sewer) and California (stormwater). One pipe in California involved a low-volatile organic compound (VOC) non-styrene resin, while all other CIPP sites used styrene resins. In Indiana, the uncured resin contained styrene, benzaldehyde, butylated hydroxytoluene (BHT), and unidentified compounds. Materials emitted from the CIPP worksites were condensed and characterized. An emitted chemical plume in Indiana was a complex multiphase mixture of organic vapor, water vapor, particulate (condensable vapor and partially cured resin), and liquid droplets (water and organics). The condensed material contained styrene, acetone, and unidentified compounds. In California, both styrene and low-VOC resin condensates contained styrene, benzaldehyde, benzoic acid, BHT, dibutyl phthalate, and 1-tetradecanol. Phenol was detected only in the styrene resin condensate. Acetophenone, 4-tert-butylcyclohexanol, 4-tert-butylcyclohexanone, and tripropylene glycol diacrylate were detected only in the low-VOC condensate. Styrene in the low-VOC condensate was likely due to contamination of contractor equipment. Some, but not all, condensate compounds were detected in uncured resins. Two of four California styrene resin condensates were cytotoxic to mouse alveolar type II epithelial cells and macrophages. Real-time photoionization detector monitoring showed emissions varied significantly and were a function of location, wind direction, and worksite activity.

Key Recommendations

Until more CIPP air monitoring and chemical toxicity data are available, the recommendation is that persons at or near CIPP sites
(1) minimize dermal and inhalation exposures,
(2) monitor emissions,
(3) use appropriate personal protective equipment (section S2), and
(4) capture emissions and confirm this by monitoring.

Important Points

1) Statements issued and distributed by NASSCO, Incorporated and distributed by other parties have incorrectly described the Purdue University study. The researchers addressed some of the incorrect information in this document.
2) Again, the Purdue University researchers offered to work with those interested in better understanding and improving worker and public safety at and near CIPP water pipe repair sites.
3) Researchers again recommended that additional investigations should be conducted to understand emissions from CIPP installations, and to determine the occupational, public health, and environmental risks.
4) Due to human health concerns, the researchers directed persons who install CIPP to contact the National Institute for Standards and Health (NIOSH) to request Health Hazard Evaluations.
5) Due to human health concerns, the researchers directed persons who visit CIPP worksites such as municipal employees and consulting engineer employees, to contact NIOSH for assistance.
6) The Purdue University researchers stated that CIPP technology could likely be used without endangering human health or the environment if appropriate safeguards were instituted.

Important Points

1) Professional Engineers who select, use, and oversee CIPP installations, have a professional and ethical duty to “hold paramount the safety, health and welfare of the public” and make only “truthful and objective statements.”
2) Engineers trained in the use of CIPP often are not warned about potentially immediately dangerous to life and health (IDLH) conditions at CIPP worksites or past air testing studies.
3) Stringent and enforced specification requirements should include proper personal protective equipment (PPE), setback distances, worksite air monitoring, capture and proper disposal of all emissions and waste, as well as the immediate reporting of complaints to health department and fire departments.