Geosynthetics June/July 2021 - 42

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Igepal CO-630
I
By George R. Koerner
An open solicitation to join a roundrobin
effort to find a substitute for
mproved stress-cracking resistance in high-density polyethylene (HDPE) geomembranes
has been a quest of our industry and a hot research topic for years. The Geosynthetic
Institute (GSI) has been working in this area since the mid-1980s. The GRI GM13 standard
specification for HDPE geomembranes has moved the ASTM D5397 (appendix) single
point notch constant tension load result requirement from 200 to 300 and finally to 500
hours over the last 30 years. It is interesting to note that some HDPE geomembrane formulations
have a considerably higher value.
Igepal CO-630 is referenced in ASTM and the European Committee for Standardization
(CEN) norms-test methods as the reagent for the stress-cracking test. Igepal CO-630's official
International Union of Pure and Applied Chemistry (IUPAC) name is octylphenoxypolyethoxyethanol.
Unfortunately, it has now been listed as a priority pollutant by some
countries and is no longer available for laboratory use in several areas, most notably in the
European Union (EU) and Canada. This development has manifested itself over the past
several years. Obviously, our industry is searching for an equivalent and is now in need of
available alternatives that can be used globally.
The EU no longer allows the sale of Igepal CO-630 to people in production industries
George R. Koerner is the
director of the Geosynthetic
Institute in Folsom, Pa.
(i.e., large quantities) due to eco-issues and health. This is apparently an EU Registration,
Evaluation, Authorisation and Restriction of Chemicals (REACH) directive, not a law. As
such, GSI has been tasked with finding a replacement for the surfactant used in several
stress-cracking tests. We know that there are hundreds of commercially available nonionic
surfactants in the family of octylphenoxypolyethoxyethanol. Unfortunately, all have unique
characteristics that will affect stress cracking in HDPE differently.
The purpose of this article is to not only make you aware of the situation, but also to
solicit help in finding an alternative. GSI is now taking a proactive approach to finding substitutes
to Igepal CO-630. We realize that these substitutes may have intensity, observable
differences and perhaps even different handling characteristics. GSI is doing preliminary
work with candidate surfactants. Please note: In addition to changing the surfactant, we
would also like to increase the bath temperature from 122˚F to 149˚F (50˚C to 65˚C) so
that we can shorten the test time.
After confirmation of an alternative group of surfactants, we want to initiate a roundrobin
test program with several geomembranes (each having different formulations). If
you would like to participate in this round-robin, please contact us at gsigeokoerner@
gmail.com. We would greatly appreciate hearing from you. G
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www.GeosyntheticsMagazine.com.
42
Geosynthetics | June July 2021

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Geosynthetics June/July 2021

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