While nonylphenol ethoxylate (NPE) surfactants in detergents have seen little regulation in the United States, government and industry have worked together to gradually reduce their use.
NPEs degrade within hours or days to nonylphenol (NP) which is the main concern for health and environment. Concerns about NP include:
- Very high persistence, bioaccumulation, toxicity (PBT) potential
- Very high acute (short-term) aquatic toxicity; high chronic (long-term) aquatic toxicity
- Moderate concern for developmental, reproductive, endocrine and other health effects
- Very high skin/eye irritation (workers)
With leadership at the national level by EPA, large-scale “industrial” laundries, hotel groups, health and long-term care systems, and many of their suppliers have significantly reduced the use of detergents containing chemicals (nonylphenol ethoxylates, or NPEs) which can harm human health and aquatic life.
Since 2013, MPCA and the Minnesota Green Chemistry Forum have worked with companies in these sectors in Minnesota to track their progress in voluntary reductions. The team estimates they have eliminated over 400 tons of NPE use per year statewide, resulting in measured reductions in levels entering waste water treatment plants of up to 40%, depending on location.
More source identification and reduction may be warranted, particularly in areas of the state using septic systems or less-advanced community waste water treatment technology.
Project contact. Al Innes, MPCA Safer Product Chemistry Coordinator: firstname.lastname@example.org or 651-757-2457.
- NPEs were eliminated from consumer detergent products.
- National and state-level action on NPEs. U.S. EPA and the Textile Rental Services Association (TRSA), representing industrial (large-scale, off-site) laundries, agreed that TRSA members would eliminate NPEs from solid and liquid detergents by 2014.
- MPCA survey of industrial laundries. In 2013, MPCA surveyed Minnesota’s major industrial laundries and confirmed they had eliminated NPE content ahead of schedule, reducing annual NPE discharge by over 300 tons, statewide.
- Sampling and analysis of Metro Plant influent (round 1). In 2014, MPCA analyzed nonylphenol (NP) and NPE concentrations in Twin Cities Main Metro Plant influent (incoming waste water, prior to any treatment), but found little significant difference versus 2006-2007 data from the same site.
- Sampling and analysis of Metro Plant domestic waste water. In early 2015, MPCA also analyzed waste water samples collected on Metro Plant subsystems with primarily domestic (household) discharge, and in general found levels one-tenth to one one-hundredth those of the plant’s influent.
- Survey of hotels, hospitals and long-term care facilities. In 2016, the Minnesota Green Chemistry Forum and interns hosted by the MPCA surveyed hundreds of hospitals, hotels, and long-term care facilities. Most respondents, particularly those facilities subject to sustainable purchasing requirements, had eliminated NPE use. Potential statewide reductions for this group are around 135 tons per year.
- Sampling and analysis of Metro Plant influent (round 2). MPCA conducted a second round of sampling of Metro Plant influent in October 2016 and found significant reductions of NP, and smaller reductions of NPEs.
In 2013, MPCA staff wanted to know the extent of Minnesota’s industrial laundries’ progress toward NPE phase-out, and if possible, what measurable effects phase-out was producing. MPCA staff generated an initial list of the five largest industrial laundry companies at 25 locations. Direct calling to these listings showed consolidation to 4 companies with 15 facilities in total. By late 2013, all larger facilities reported switching away from detergents containing NPE. Among smaller firms/facilities, MPCA staff found only two of the smaller facilities using detergents containing NPE. Staff educated these firms about the concerns related to such use and the availability of safer alternative choices.
The CleanGredients® database includes over 300 surfactants reviewed and found to meet EPA Design for the Environment’s Criteria for Safer Surfactants. However, each potential NPE alternative must be evaluated on a case-by-case basis as to both its safety profile and functional characteristics. Cost is a considerable factor as well, sometimes screening out alternatives prior to reformulation and performance testing.
The main NPE alternatives currently in use include alcohol ethoxylates (both linear and branched), and glucose-based carbohydrate derivatives such as alkylpolyglucoside, glucamides, and glucamine oxides (EPA Action Plan). Formulators may replace an NPE surfactant with a blend of two or more surfactants (e.g., a linear alcohol ethoxylate, or LAE, plus an alkyl glucoside). Chemicals which meet the Criteria for Safer Surfactants are acceptable for use in an EPA Safer Choice-labeled detergent or cleaning product (EPA Alternatives Assessment).
Information MPCA staff gathered from large facilities confirmed that linear alcohol ethoxylates (LAEs) are the most commonly used alternative to NPE.
Estimates provided voluntarily by twelve of the larger industrial laundries showed they had eliminated about 646,000 pounds (323 tons) of NPE use and discharge per year, statewide. Seven of these twelve laundries which eliminated NPE discharge are in the Metro Twin Cities Main wastewater treatment plant sewershed, and MPCA estimates their total annual reduction at 179 tons, 55% of the statewide figure. This apparently large reduction led MPCA staff to expect to see some reduction in Main Plant influent concentrations. However, analysis in the fall of 2014 of 24-hour composite samples of that influent showed little change versus baseline data from influent sampling done in 2006 and 2007.
On the plus side for the Main Plant, even though NP and NPEs remained elevated coming into the plant (up to 30,000 nanograms/liter), they are removed down to the level of hundreds of nanograms/liter in final effluent. Advanced POTW systems may be having success in removing them from water, but this may not be the case with other public systems, private direct dischargers, or septic systems. In addition, large POTWs are transferring some of these (and other) compounds to their sludge (biosolids), which in many cases is land-applied where further impacts may occur. For these reasons, source reduction remains important.
MPCA staff made calls in 2015 to a number of familiar hotel brand locations clustered around the Mall of America (Bloomington, Minn.) about whether they are washing laundry in-house, versus sending it out to the industrial laundries which accomplished the phase-out. Staff learned that most of the larger hotels were laundering in-house, and some were using detergents containing NPEs. Other large institutions which might be doing the same include hospitals and other health care facilities, short and long-term care facilities, prisons, and others yet to be identified. Smaller dischargers could include car washes.
With this information that further commercial/industrial uses of NPE surfactants remain, MPCA chose to use the remainder of its limited sampling funds to work with MCES to sample four points upstream in the Main Plant sewershed where residential (domestic) sources were dominant. Results of lab analysis showed 3 out of 4 of those sites had concentrations that were 1 to 2 orders of magnitude lower than Main Plant primary influent, suggesting relatively little contribution from household cleaners, paints, or residue in clothing. Two samples taken within 4 days at the fourth site averaged around 12,000 ng/L NPE, but when drive-through inspections of the area showed no apparent commercial operations or other activity, MPCA concluded that this level was anomalous.
Based on the activity described above, the Minnesota Green Chemistry Forum (MGCF) Steering Committee decided to co-sponsor the next phase of NPE work, to confirm the presence or absence of NPEs in detergents in other large-scale operations cleaning rugs, uniforms, linens, towels, or other fabrics – including hospitals, hotels, and residential care facilities. Prisons are believed to be covered by State purchasing contracts (shared with county and local entities) restricting use of detergents containing alkylphenol ethoxylates including NPE. Where NPEs were found, reduction efforts would be invested and hopefully, measured.
Under the direction of an MGCF work group and MPCA staff from January through May 2016, three interns from Minnesota colleges conducted on-line surveys through key partners and associations, e-mail queries, and phone interviews attempting to get voluntarily supplied information from various types of facilities. MGCF and MPCA extend a special note of appreciation to those interns: Lena Schaller (Macalester College), Nathan Mitka (St. Olaf College), and Sarah Showalter (St. Catherine University).
In short, the project team found:
- little remaining use of detergents containing NPE among larger, centrally managed hotel, health care, and long-term care systems;
- isolated use by single facilities or franchises, particularly outside the Twin Cities Metropolitan area;
- some opportunities for further investigation and assistance among the isolated users, and with their suppliers or service providers;
- only one opportunity to collect numeric data, as a result of finding little current use of NPE detergents;
- based loosely on what was found in data gathering in 2016 versus cursory collection in 2013, increased attention since then in corporate sustainability programs and purchasing requirements on eliminating NPEs in detergents.
The project team identified Minnesota manufacturers which have detergents which meet the U.S. Environmental Protection Agency’s Safer Choice Standard or the independent non-profit organization standard, Green Seal. Both of these third-party certified standards rule out NPE plus other chemicals (e.g., optical brighteners, fragrances) with potential hazards which may be used in detergents.
Minnesota manufacturers with certified detergents include Anderson Chemical Company, Ecolab, and Sunburst Chemicals. In addition, MPCA staff reviewed data sheets for some of Ver-tech’s products and found them not to contain NPE. Technical contacts for these companies are provided at the bottom of this page.
In one instance, the project team followed up with a survey respondent from a western Minnesota city who managed the combined laundry of a hospital with 25 beds and long-term care facility with 57 beds. By phone, the team discussed their fabric care situation and provided resources on certified/reviewed Minnesota products and technical contacts from the manufacturers. The manager worked with one of the suppliers provided, selected a Safer Choice-certified substitute, successfully made the replacement, and reported being very satisfied with its performance after five months.
This facility had an annual purchase of 600 pounds per year of detergent, and with the previous detergent estimated to contain 10-30% NPE by weight, the team calculates a midpoint 120 pound per year (1.5 pounds per bed per year) reduction in NPE use and discharge to the city’s wastewater treatment plant. A second facility reported using 756 pounds per year for 75 beds, which at 20% NPE calculates to 2 pounds NPE per bed per year.
The project team produced an estimate of about 183,000 total beds in Minnesota for which linen was laundered on-site, based on data from a number of sources specific to healthcare and hospitality.
If all linen for this number of beds was previously washed with detergents containing NPE, then based on the low-end estimate of 1.5 pounds NPE per bed per year, their NPE usage was on the order of 135 tons per year statewide, well under the 323 tons per year estimated for Minnesota’s large industrial laundries.
However, this potential reduction was significant enough to suggest resampling influent to the Metro Twin Cities Main Plant wastewater treatment plant to look for impacts on concentrations of alkylphenols, prior to further work on finding and reducing other NPE uses.
In October 2016, MPCA worked with Metro Plant staff to gather 24-hour composite samples at the same spot (influent, prior to any treatment) in the system. Analysis of the 2016 samples, by the same lab and method used in 2014, showed a statistically significant decline of over 70% in 4-nonylphenol (CAS 84852-15-3) concentrations from October 2014, after normalizing for different flow rates. The 2014 mean was 28,720 ng/L; the 2016 mean was 8,455 ng/L.
The lab also analyzed for the same two NPE groups in 2014 and 2016:
- 4-nonylphenol monoethoxylates (CAS 104-35-8)
- 4-nonylphenol diethoxylates (CAS 20427-84-3)
Each group declined by over 40%, but this was determined not to be a statistically significant difference. The mean for the total of the two NPEs in 2014 was 46,684 ng/L; in 2016, it was 27,030 ng/L.
Minnesota manufacturers with non-NPE detergents
Purchasers can ask unaffiliated distributors if they carry any of the listed NPE-free products, or other laundry detergents with clear documentation that they do not contain NPEs or other components of potential concern.
Anderson Chemical Company (Litchfield)
Contact - Marlene Williams: 320-593-4518 or email@example.com
Ecolab Inc. (St. Paul/Eagan)
Contact - Call the 800-352-5326 service line to get started. Your request then goes to Ecolab’s Territory Manager, who will be your technical contact; or e-mail firstname.lastname@example.org
Sunburst Chemicals, Inc. (Bloomington)
Contact - Jack Heaviside: 314-712-9448 (mobile) or email@example.com
Company documentation (MPCA review of Safety Data Sheets); not third-party certified
Ver-tech Solutions & Services (Rockford)
Contact - Jami Sloan: 877-866-9742 x221 or firstname.lastname@example.org