Is there evidence to suggest concern about epoxy safety?  

Prior to its use in pipe-lining, epoxies have served as barrier coats in water storage vessels. This process is 

much simpler than lining a pipe, but the process and chemistry are still complex, and there are many 

opportunities for problems. Failures in substrate preparation, e.g., insufficient drying, errors in mixing of 

ingredients, etc., may lead to problems in the finished coating, some of which can affect barrier integrity (6). An 

incorrect formulation could lead to incomplete curing and the potential for chemicals to leach from the coating 

into drinking water. 

 

Water contamination from some epoxy pipe-lining materials has been found in independent laboratory tests. 

Alben el al. found that methyl isobutyl ketone and xylene leached from epoxy-coated test panels and from 

epoxy-lined water storage tanks [cited in (5)]. Hazardous volatile organic chemicals, among them benzene and 

                                                 

1 

 ANSI – American National Standards Institute,  NSF – National Sanitary Foundation 

2 

 For example, with the USEPA listed organic contaminants, the ANSI/NSF 61 standard requires that contaminant 

levels be no more than one-tenth of the maximum level allowed in water by the USEPA or other regulating authorities. 

xylene, were found to leach from epoxy into water at levels above the acceptable maximum specified by US 

and Canadian regulations, and some of the tested materials were ANSI/NSF 61 certified (7). The Satchwill 

report concludes, “It was found that these linings can cause significant contamination of the drinking water” (7). 

 

The US military services have used epoxy pipe-lining since the 1990’s to deal both with high corrosion 

environments aboard ships and for pipe-rehabilitation to avoid lead contamination in drinking water (8) 

(9). In 1992, the Naval Research Laboratory’s (NRL) coating development program was delayed and 

forced to shift to new formulations. Changes in federal regulations that year tightened restrictions on 

one of the existing coating components, a toxic, carcinogenic epoxy hardener, 4,4'-methylene dianiline 

(10). While the main concern was safety of the epoxy workers, the components of some epoxy systems 

used for pipe rehabilitation clearly pose a potential risk for toxic chemical contamination.  

 

In the United Kingdom (UK), epoxy-lining for pipe rehabilitation began in the 1970’s and became common- 

place in the 1990’s (11). Concerned that the aging of rehabilitated piping systems might pose health hazards, 

regulators commissioned a study. The 2007 report to the UK Drinking Water Inspectorate concluded that, 

“...any leaching from the pipe linings is at a low level” (11). Pipes lined with five UK-approved epoxy 

formulations were surveyed. The report notes that, “Evidence of leaching of 4-t-butylphenol (4-TBP) from 

Resin C was found...”, however, the concentration was quite low (in the part per billion range). While 4-TBP is 

an irritant, it is not otherwise believed to present a significant health risk.3 It is important to note that in the UK, 

in-place epoxy-lining can only be performed by approved contractors.  

 

Some epoxy materials used for pipe-lining are formed from the controversial bisphenol-A (BPA). 

Repeated studies by the US Centers for Disease Control and Prevention have detected BPA in the 

urine of 93% of tested individuals (age 6 and above) (12). BPA is an endocrine disruptor, and there are 

significant concerns about the safety of chronic exposure to low-levels in food (13). While pipe-lining 

suppliers say their products are safe, vendor documents acknowledge that there is some risk for 

bisphenol-A exposure above ANSI/NSF 61 certification levels when lining installation procedures are 

not rigorously followed (14). 

 

Most vendor websites provide little detail on the chemical formulations of their epoxies. Even worse, there may 

be serious inaccuracies, for example, the Cleanncoat site states, “...CleanncoatTM does not use any chemicals 

in the pipe restoration process. We use three elements: air, sand, and epoxy” (15). There is no doubt that 

chemicals, and in some cases hazardous ones, are used to produce epoxy pipe-linings. Any claim to the 

contrary should be a red-flag for potential customers.   

Table 1. BPA U.S. Consumption and Assumed Share Within TSCA Jurisdiction 

Product  Percent of BPA U.S. 2007 

Consumption1 Assumed TSCA share 

2 

 

Polycarbonate resins  74% 62 -  64 % 

Epoxy resins    20% 18 - 20 % 

Flame retardants; Polyetherimides/ 

Polyarylates; Polysulfone resins; Unsaturated 

polyester resins 6% 5 - 6 % 

               Total 100% 85 - 90 % 

 

Table 2:  BPA Intake Limits for Human Health Assessments 

Authors Intake Limit 

(mg/kg/day) 1 Endpoint (Animal dose in mg/kg/day) And Study 

USEPA (Integrated 

Risk Information 

System;  IRIS (1993)) 

0.05 Reduced body weight (5) 

NTP 1982 two year cancer study in both rats and mice (as 

cited in USEPA 1993) 

0.005 Systemic – reduced body wt and liver effects (5) 

 

 

0.5 Reversible reproductive effects (50) 

 

(All based on both 2-generation mouse study (Tyl et al., 

2008) and 3-generation rat study (Tyl et al., 2002)) 

EFSA (2006, 2008a-b) 

and EC (2003, 2008) 0.05 Used 5 (lowest value in cited studies)  Tyl et al. (2002, 2008) 

0.05 

0.5 Body weight (5) Reproduction (50) 

Tyl et al., (2002, 2008) 

Cited numerous studies with effect levels ranging from 0.010 

to 0.100 mg/kg/day for a variety of effects in mice and/or rats 

including changes in: maternal behavior, gender-specific 

behaviors; sexual performance; novelty-seeking/impulse 

behaviors; avoidance response; maze performance. 

Willhite,et al. (2008) 

(NSF International) 0.016 Used 5 (lowest value in cited studies)  Tyl et al., (2002, 2008) 

1 

  Most risk assessments take an exposure value from an animal study (dose in mg/kg-bw/day) and divide it 

by several uncertainty factors to arrive at an acceptable dose in humans. This value is what is shown here as 

an “intake limit” and is what is compared to an expected/estimated exposure value in a risk assessment. 

BPA-based materials are pervasive in the U.S. economy. Apart from food-related uses, 

they are used in automotive and other transportation equipment, optical media such as DVDs, 

electrical/electronics equipment, construction, linings inside drinking water pipes, thermal and 

carbonless paper coatings, foundry casting, and elsewhere. A handful of companies manufacture 

most BPA, as well as most BPA-based polycarbonate and epoxy resins, but numerous companies 

process BPA-based materials into final goods.  

http://en.wikipedia.org/wiki/Bisphenol_A

What is bisphenol A?

Bisphenol A (BPA) is a widely produced chemical used primarily for the production of polycarbonate plastics and epoxy resins. More than 6 billion pounds of BPA are produced and used each year for this purpose. The use of this chemical is so profound that it was detected in the urine in 93% of the population over 6 years of age. The study did not include anyone under 6 years of age, so the level in their urine is unknown.

Polycarbonate plastics are typically hard and clear and are marked with the resin identification code number 7. As mentioned previously, the number 7 is considered the "other" category and includes chemicals other than bisphenol A. Nalgene water bottles were made with BPA until recently. They are being voluntarily pulled from the shelves and replaced by bottles that are BPA-free made with a relatively new plastic called Tritan copolyester. Other sources of polycarbonate are food and drink packaging, including infant bottles, toddler sipping cups, tableware, and food containers. Epoxy resins are used to line metal products such as canned foods, bottle tops, and water supply pipes.