Kwik Zip tower ad
Kwik Zip tower ad

CIPP emissions safety review non-conclusive

A literature review of chemical emissions from cured-in-place pipe (CIPP) resin has been non-conclusive.

Late last year, the National Association of Sewer Service Companies (NASSCO) made a request for proposals for a formal review of the potential safety impacts associated with CIPP, particularly relating to the chemical emissions of styrene-based resins released during the steam curing process.

The study began in December 2017 after it was awarded to researchers at the University of Texas at Arlington’s Center for Underground Infrastructure Research and Education (CUIRE), who also received support from the Institute for Underground Infrastructure (IKT) in Germany.

CUIRE aimed to evaluate the current literature about the impact of emissions on the safety of construction workers and the general public during rehabilitation works.

The results of the study were released on 30 April 2018, finding that previous studies capture the variation in emissions around the termination manhole or in the sewer pipe itself, which is not helpful in evaluating the safety impacts as workers and members of the public do not enter these locations.

CUIRE also found that the previous studies also fail to capture emissions from a range of pipe shapes and sizes, and inconsistent methodology.

Due to this inconsistency, and the questionable methodologies across the 21 papers reviewed, the results are non-conclusive and the researchers recommended additional sampling and analysis as a second phase of this study.

On 3 May 2018, NASSCO opened a CIPP emissions study request for proposals to “evaluate the potential release of organic chemicals in the steam exhaust and other release points during pipe rehabilitation using the trenchless CIPP method”.


In July 2018, NASSCO announced that it had awarded the comprehensive CIPP emissions study to the Trenchless Technology Center at Louisiana Tech University.

For more information visit the NASSCO website.

If you have news you would like featured in Trenchless International contact Assistant Editor Chloe Jenkins at

First published 9 May 2018.

Show more

Related articles

Back to top button