Aquatic Life Water Quality Standards 

Technical Support Document for 

Nonylphenol and Ethoxylates 

Triennial Water Quality Standard Amendments to Minn. R. chs. 7050 and 7052 

DRAFT For External Review, October 14, 2010 

TBD 2010
Minnesota Pollution Control Agency 

520 Lafayette Road North | Saint Paul, MN 55155-4194 | www.pca.state.mn.us | 651-296-6300 

Toll free 800-657-3864 | TTY 651-282-5332 

This report is available in alternative formats upon request, and online at www.pca.state.mn.us 

Document number: wq-s6-16 

Authors 

Phil Monson, M.S. 

Contributors / acknowledgements 

Angela Preimesberger, M.S. 

 

 

 

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3 
Technical Support Document for 2008-2012 Triennial Rule Amendments 

TECHNICAL SUPPORT DOCUMENT FOR NONYLPHENOL AND NONYLPHENOL ETHOXYLATES 

Contents 

Abstract ................................................................................................................................................................... 5

INTRODUCTION ....................................................................................................................................................... 6

Nonylphenol ethoxylates in the environment ........................................................................................................ 6

HOW AND WHY WATER QUALITY STANDARDS ARE DEVELOPED .......................................................................... 6

U.S. EPA National Clean Water Act 304(a) Aquatic Life Criteria ................................................................... 6 

Development of aquatic life criteria for nonylphenol ethoxylates ............................................................... 7 

Endocrine-active endpoints for nonylphenol ethoxylates ............................................................................ 8 

Draft Water Quality Standards for Nonylphenol and Ethoxylates ......................................................................... 9

Minnesota aquatic life WQSs for nonylphenol ethoxylates ......................................................................... 9 

Considerations of Human health in aquatic life criteria ............................................................................. 10 

Implementation .......................................................................................................................................... 10 

References 19 

4 
Abstract 

From the Minnesota State Register, Volume 33 (35), March 2, 2009: 

Nonylphenol (NP) is an industrial chemical used primarily as an intermediary compound in the development of 

numerous commercial non-ionic surfactants. These surfactants are ingredients of detergents and emulsifyers 

found in household, industrial, agricultural, and other applications. The chemical makeup of the surfactants is 

largely in the form of nonylphenol and octylphenol ethoxylates, more broadly referred to as alkylphenol 

ethoxylates (APEs). Concentrations of these APEs primarily consist of nonylphenol ethoxylates (NPE) and have 

been reported from water samples collected from studies of the Mississippi River, smaller Minnesota streams, 

and wastewater effluents. Sources of NPEs to the environment include point and nonpoint discharges to 

surface waters. Under anaerobic conditions NPEs breakdown to NP. 

 

 Nonylphenol is toxic to aquatic organisms demonstrated, in part, through recent national criteria 

established by the EPA (AWQC– Nonylphenol 2007( EPA822R05005)). The need to develop national criteria 

was based both on concerns of NP toxicity and its presence in surface waters throughout the nation. The 

capacity of NP as an endocrine-disrupting compound is also documented in the EPA criteria document and in 

numerous reports in the scientific literature. Endocrine-disrupting chemicals (EDCs) are those compounds 

[human-made compounds or natural compounds at unnatural concentrations due to human activity] that exert 

an adverse effect through interaction with the endocrine system of mammals, birds, fish, amphibians and 

many invertebrates [from the MPCA’s Legislative report on 

EDCs www.pca.state.mn.us/publications/reports/lrp-ei-1sy08.pdf]. 

 

The Minnesota Pollution Control Agency (MPCA) has reviewed the EPA AWQC and recent literature to develop 

draft numeric acute and chronic water quality criteria as the basis for future proposed Water Quality 

Standards (WQSs). Based on the available data on NP and NPEO, MPCA ‘s acute (FAV and MS) and chronic (CS) 

criteria were developed to be total NPE concentrations (NP plus two short chain ethoxylates, NP1E0 and 

NP2EO). MPCA reviewed EPA’s conclusions on the EDC studies that suggest while the draft chronic criteria are 

not based specifically on EDC –mediated effects, would be protective of chronic adverse effects observed in 

aquatic species studies that impact aquatic communities. 

5 
Introduction 

Nonylphenol (NP) is a mixture of isomers of branched and substituted structures within a nonyl (9 carbon) 

group formed in the process of petroleum distillation. Nonylphenol is produced in large quantities in the 

United States with estimates of over 200 million pounds produced per year. Commercial production limits the 

number of isomers to a few primary products dominated by the chemical 4(para)-nonylphenol (4-NP). 

Nonylphenol alone has limited use, but is an ingredient in the manufacture of a wide variety of alkylated 

products broadly described as nonylphenol ethoxylates (NPEO). These compounds have a primary use as nonionic surfactants in commercial and household cleaning products, industrial materials processing, and 

additives to pesticide formulations and industrial lubricants. The focus of this discussion will be placed on 4-NP 

and two short-chain ethoxylates: nonylphenol mono-ethoxylate (NP1EO) and nonylphenol di-ethoxylate 

(NP2EO). For purposes of this document, the term nonylphenol ethoxylate (NPEO) will be used inclusive of the 

chemicals 4-NP (CAS #: 84852-15-3, NP1EO (CAS #: 27986-36-3) and NP2EO (CAS#: 20427-84-3). 

Nonylphenol ethoxylates in the environment 

Nonylphenol ethoxylates are often constituents of municipal or industrial wastes in effluent discharges to 

surface waters. In Minnesota, NPEO has been found in surface waters and sediments from around the state 

(Lee et al. 2004; Lee et al. 2008; MPCA 2009). Regular monitoring for NPEOs in Minnesota surface waters is 

limited due to lack of standardized analytical procedures and regulatory necessity. Nonylphenol ethoxylates 

inputs to surface waters and associated treatment facilities are a various mix of 1-20 carbon chain 

polyethoxylates. The short-chain (1 or 2 carbon) ethoxylates and 4-NP tend to be the most toxic to aquatic 

organisms (Servos 1999; Bistodeau et al. 2006), and are the most persistent forms in wastewater. Initial 

degradation of longer (3- 20) chain ethoxylates occurs through natural processes resulting in their breakdown 

to the less water soluble NP1EO, NP2EO and 4-NP (Soares 2008) . The two short chain intermediate 

compounds (NP1EO, NP2EO) may degrade further to 4-NP, but all three tend to resist degradation and are 

often found in sediments, wastewater sludge, and wastewater effluents. 

HOW AND WHY WATER QUALITY STANDARDS ARE DEVELOPED 

U.S. EPA National Clean Water Act 304(a) Aquatic Life Criteria

The MPCA is required by federal law to assess and revise its rules that protect the designated, beneficial uses 

of state surface water and groundwater. Mandates under the Clean Water Act maintain a state’s requirement 

to develop water quality standards (WQSs) for the protection of aquatic life communities. The U.S. 

Environmental Protection Agency (EPA) is responsible for developing these 304(a) Ambient Water Quality 

Criteria (AWQC) on a national basis, and it is up to the state to use or modify criteria based on more local and 

scientifically defensible data that are still as protective as national criteria. Concern for the protection of 

aquatic life prompted the to develop national aquatic life AWQC for nonylphenol, centering on the compound 

4-nonylphenol (EPA 2005). The national criteria for freshwater aquatic life are based on evaluation of toxicity 

endpoints of nonylphenol to aquatic organisms. This document pursues the development of numeric 

standards derived for the combined concentrations of the three most toxic and persistent nonylphenol 

ethoxylate compounds, 4-NP, NP1EO and NP2EO as the basis for draft acute and chronic WQSs. 

6 
Development of aquatic life criteria for nonylphenol ethoxylates 

Toxicity data for NPEO used to develop a numeric standard was evaluated through national guidance provided 

by the EPA (USEPA 1985) and requirements in Minn. R. chs. 7050 and 7052. Briefly, studies from the scientific 

literature are assembled, acceptable toxicity endpoints and taxonomic categories are compiled, and a species 

sensitivity distribution is calculated that assumes protection of about 95% of aquatic communities. Effects of 

NPEO on aquatic organisms were assessed for survival endpoints reported from short-term (acute) laboratory 

exposures. The primary mode of action of NPEO on the whole organism is generally considered a narcotic 

effect. Toxicity tests are described as the lethal or effect concentration of 50% of the (test) population, 

referred to as LC50 or EC50, respectively. These endpoints serve as the basis for developing the species 

sensitivity distribution as described in the EPA guidance. 

Scientific studies were evaluated for acceptable data based primarily on information provided in the 1985 EPA 

Guidelines and ASTM methodologies (ASTM, 2009). Toxicity information used for development of this numeric 

standard included those data published in the EPA national AWQC document augmented with additional 

reports from studies published over the past ten years. Development of a numeric standard combined toxicity 

results of the three related nonylphenol compounds: 4-NP, NP1EO and NP2EO. Most toxicity information is 

based on tests using the compound 4-NP. Additional literature includes studies that reported results for six 

aquatic species in exposures to NP1EO and NP2EO (Table 1). Results of three of these studies could not be 

used as two were from species of a non-native frog, and one used a mixture of unreported nonylphenol 

ethoxylates (NPEO). 

Studies with acceptable NPEO data provided values used to calculate a numeric standard for 23 freshwater 

genera comprising 28 species from 81 acute toxicity endpoints. Data sources for these endpoints were 

combined from sources of the existing EPA AWQC document and the open literature (Table 2). Species acute 

sensitivity to NPEO ranged from 55.72 micrograms/liter (μg/l) for Hyalella to 4108.6 μg/L for Xenopus. Use of 

Xenopus extends the convention of developing an aquatic life standard from toxicity test using only native 

species. However, Xenopus is an accepted laboratory test species demonstrated, in part, through its use in 

toxicity testing using FETAX methods (ASTM 2004) and methods employed by the EPA to examine endocrine 

disrupting compounds. A comparison of reported endpoints between NPEO and 4-NP tend to show that the 

short chain ethoxlylates are slightly less toxic than 4-NP for the species tested. This observation has been 

reported from other sources (EPA 2005; Servos 1999). Studies reporting toxicity endpoints for short-chain 

ethoxylates are few, and these toxicity values are disbursed throughout the range of endpoints for all NPEO. 

As such, values reported for toxicity endpoints of 4-NP, NP1EO and NP2EO are considered together as equally 

toxic and deemed appropriate for inclusion in deriving the numeric standards. Additional information on the 

combined toxicity of NP, NP1EO and NP2EO to aquatic life may be available following actions of rulemaking 

recently proposed by the EPA (Federal Register 2009). 

Table 3 provides a summary of the Minnesota Pollution Control Agency’s (MPCA) draft WQSs. The calculated 

Final Acute Value (FAV) of 59.78 μg/L for NPEO compares to the national criterion FAV for freshwater of 55.49 

μg/L for 4-NP. This difference can be explained in part as both the total number of geometric mean acute 

values (GMAV) and the GMAVs for the four lowest taxa are slightly higher in development of this numeric 

standard compared to the national criteria. Developing numeric standards that includes effects of NPEO is 

reasonable because: 1) short-chain ethoxylates are expected to be the most common form of NPEO in surface 

waters. They are the most recalcitrant form in the ethoxylated chain degradation, and are most likely to be a 

7 
component of effluent discharges, 2) These short-chain NP ethoxlylates degrade further to 4-NP under 

anaerobic conditions found in many aquatic sediments. A numeric standard for NPEO serves to reduce the 

total amounts of 4-NP present in the environment by also reducing the potential release of the short-chain 

ethoxylates. 

Calculation of chronic standard (CS) values can be achieved in one of two ways. Given sufficient chronic 

toxicity data to fulfill the Tier I taxonomic categories, a chronic value can be calculated in the same manner as 

the acute value. With insufficient chronic toxicity data, an acute to chronic ratio can be used. The latter 

method was used to compute the acute to chronic ratios (ACR) available for three freshwater species. National 

freshwater AWQC are based on an ACR for an estuarine species, which was not used for this numeric standard 

development. National guidelines suggest that choice of an ACR be determined using either 1) the geometric 

mean of three or more ACRs if there is no apparent trend between ACR values and acute toxicity values, or 2) 

the ACR for the study pair that had a GMAV closest to the calculated FAV. The former method was selected as 

no apparent trend could be discerned from the data. It was observed that fish appear to have large differences 

between their acute and chronic endpoints, so it was important that the one ACR available for fish (rainbow 

trout) be included in the calculations of the final ACR (8.023). Also, as fish appear to have greater chronic 

sensitivity and rainbow trout are an important aquatic species in Minnesota, a chronic standard for cold-water 

(class 2A) uses was calculated using the ACR (28.11) for rainbow trout. The chronic standard for all other class 

2 waters was calculated using the geometric mean ACR for the three species shown in Table 2. 

Studies have reported chronic effects of NPEO on aquatic organisms using conventional endpoints that 

represent effects on populations of aquatic animals (i.e., survival and growth), but were not sufficient for Tier 

1 assessment. The national AWQC document provides an examination of chronic effects reported from the 

literature through 2005. 

Endocrine-active endpoints for nonylphenol ethoxylates 

Nonylphenol is documented as an endocrine active compound (EAC) described in part through its estrogenic 

activity in aquatic organisms, particularly vertebrates (EPA 2005). Endocrine Active Compounds are broadly 

described as chemicals that exert effects attributed to disruption of the endocrine system, which regulates 

critical growth, developmental and reproductive aspects of an organism’s life cycle. These sorts of compounds 

are also referred to as endocrine disrupting compounds, but the term EAC serves to better describe the 

activity of these compounds in biological systems. Current understanding of EACs characterize them through 

both activational (e.g., vitellogenin production) and organizational (e.g., intersex) endpoints, and a variety of 

measured responses through histological, physiological, molecular (i.e., protein, gene) and other observations. 

This document, however, will not be developing aquatic life WQSs based on endocrine-active endpoints. The 

challenge with developing numeric standards based on EAC endpoints is the scientific information gap, specific 

to NPEOs, that precludes a connection of these endpoints to effects at the population level1

. 

Research with NPEO has documented effects of estrogenic exposure in organisms to responses measured 

through chemical reproductive proteins (e.g., vitellogenin induction) and their cellular precursors (e.g., m-RNA 

induction) (Vazquez-Duhalt 2005). These chemical biomarkers also have been associated with internal effects 

(e.g., gonadal deformities), external effects (anatomical deformities, secondary sex characteristics), and some 

limited reproductive (fecundity, hatching success), behavioral (spawning success) and other effects (growth, 

8 

 

1

 Other environmental pollutants that have relevant ecological effects data for evaluating population level effect are discussed in the 

MPCA’s 2008 Legislative Report, Endocrine Disrupting Compounds (at http://www.pca.state.mn.us/publications/reports/lrp-ei1sy08.pdf). 
survival). Absolute outcomes of toxicity tests using NPEO, however, have yet to report definitive doseresponse and endpoint calculations that are critical to development of numeric standards for aquatic life. 

As NPEO comes from entirely anthropogenic sources, surveys of wastewater effluents and ambient waters 

have detected these compounds in a number of sites in Minnesota (Lee et al. 2004 and 2008). In conjunction 

with this analysis, laboratory studies have examined organism responses to exposures of whole effluent 

dilutions and aqueous solutions spiked with relevant concentrations of nonylphenols ( Bistodeau et al. 2006, 

Schoenfuss et al. 2002). Outcomes from these tests did not produce any absolute connections to reproductive 

effects. Recently, Schoenfuss (2008) showed that chronic exposures of fathead minnow to nonylphenols in 

wastewater effluent affected spawning behavior of males. Results of these tests do not include conclusive 

dose-response characteristics, but serve to provide additional information of possible population-level effects 

in connection with wastewater effluents containing measurable amounts of NPEO. Numerous studies have 

examined behavioral and reproductive-related effects following exposure to whole effluents, mixtures and 

treatments containing nonylphenol and octylphenol ethoxylates. Dr. Scheonfuss is currently engaged with the 

agency in efforts that include assessing reproductive effects in female fathead minnows. 

The intent of this standards development is to ensure additional protection to aquatic organisms from 

exposure to the broader suite of nonylphenol ethoxylates through attempting to keep the most toxic 

compounds (4-NP, NP1EO and NP2EO) from entering the environment. A cursory examination of the recent 

literature (i.e., ECOTOX database search) suggest that many studies reporting chronic effects of NPEO focused 

more on assessing endocrine active endpoints. These too were reported in the national criteria document as 

other endpoints (US EPA 2005; Table 6). From these (Table 6) data, a species sensitivity distribution was 

created (Figure A) that offers a relative comparison between this range of endpoints and the chronic value of 

NPEO developed for the draft CSs. The species sensitivity distribution was plotted using the online EPA 

program CADDIS (US EPA 2000). This exercise was not meant to prescribe any definitive measure of effect on 

the aquatic community, but it may serve to provide some insight toward the relative protection offered by the 

draft Minnesota chronic standard to aquatic life. 

 

Draft Water Quality Standards for Nonylphenol and Ethoxylates 

Minnesota aquatic life WQSs for nonylphenol ethoxylates 

The MPCA has decided to adopt criteria values for nonylphenol ethoxylates best described as 4-nonylphenol 

(CAS number 84852-15-3), NP1EO (CAS number 104– 35–8) and NP2EO (CAS number 27176– 93–8). 

Development of a state standard for this suite of NPEO serves both as a means to adopt water quality 

standards that fulfill the Clean Water Act mandate and provide better protection for aquatic life uses in the 

state. Adopting these standards for NPEO versus standards for 4-NP alone is better suited because the realistic 

environmental exposure to aquatic organisms is not restricted to a single chemical. 

Sources used to gather information needed for the development of aquatic life criteria were retrieved from a 

search of academic databases. Primary databases were Scirus (www.scirus.com), Google Scholar 

(scholar.google.com), University of Minnesota library, MPCA library resources, U.S. EPA ECOTOX and other 

sources. The national criteria document (US EPA 2005) provided the majority of the toxicity data used for the 

Minnesota criteria development. 

9 
The Aquatic Life Summary Sheets (Table 3) presents the technical detail for the Class 2 Final Acute Value (FAV) 

and Chronic Standard (CS) value of 59.78 μg/L, rounded to 60 μg/L, and 7.4 μg/L, respectively. Additionally, a 

separate chronic value for cold water uses (Class 2A) of 2.4 μg/L was developed for the protection of coldwater fish. Development of these Minnesota standards considered additional data from the scientific 

literature that expanded upon studies using 4-NP, NP1EO and NP2EO. Results of those tests did not show 4- 

NP to be considerably more toxic than NP1EO or NP2EO, and the addition of toxicity test endpoints for more 

species serves to better reflect a broader aquatic community response. Inclusion of one study using the 

amphibian Xenopus, though not particularly sensitive, offers a broader perspective of surrogate test species. 

Minnesota standard calculations also added to the calculation of an acute to chronic ratio (ACR). In efforts to 

better reflect the freshwater focus of Minnesota criteria, the national ACR using a saltwater species was not 

included in the final ACR used for deriving a chronic value. 

Considerations of Human health in aquatic life criteria 

The national AWQC for nonylphenol (US EPA 2005) only developed aquatic life acute and chronic standards 

and did not include a review of human health-based chronic criterion. EPA has also not published toxicological 

values for use in risk assessment in the Integrated Risk Information System (IRIS). Developing water quality 

standards also include review of available data to evaluate the beneficial uses of drinking water, fish 

consumption, and recreational primary contact. MPCA works closely with the Minnesota Department of 

Health (MDH) on toxicological evaluations and had requested a human health review to ensure that the 

chronic standard being developed will be protective for both aquatic communities and human health (MDH 

2009). MDH provides toxicological data reviews used by MPCA since the 1990 adoption of human healthbased methods and standards. Prior to recommending toxicological values for use by MPCA, the dataset has 

to meet their criteria for sufficient and acceptable data (e.g. MDH HBV level- reference doses and appropriate 

drinking water intake rates). At this time, MDH did not develop a final reference dose or provide human health 

risk assessment advice (RAA) for nonylphenol. However, a survey of available secondary literature revealed 

sources of information about the mammalian toxicity of nonylphenol to suggest that the human health-based 

WQS would not be as stringent as the chronic standard developed to protect aquatic life. As a review of 

primary information sources was not possible, the presentation of these results could not be used in the 

development of NPE standards. MPCA will continue to evaluate the availability of final toxicological 

assessments by EPA’s IRIS and MDH for future consideration in WQSs. 

Implementation 

WQSs are expected to be assessed and updated every three years according to provisions in the Clean Water 

Act. The MPCA has the responsibility for assessing existing water quality standards and for considering any 

new or existing national criteria for surface waters to develop WQSs. Developing Minnesota WQSs for 

nonylphenol ethoxylates is based on lack of existing criteria or WQSs for these chemicals and availability of 

National AWQC to provide guidance only for 4-nonylphenol. Based on additional research data, MPCA 

augmented the National criteria values by adding the two short-chain ethoxylates (NP1EO, NP2EO) when 

developing protective values for the three most toxic nonylphenol ethoxylates. A study of selected surface 

waters in Minnesota found nonylphenol ethoxylates present in many lakes and streams, and not always 

associated with wastewater sources (Lee et al. 2009). Setting values protective of aquatic life for NPEOs offers 

a better assurance that these anthropogenic chemicals are less likely to be released to the environment. 

10 
Methods for chemical analysis of nonylphenol ethoxylates are available through select laboratory procedures 

and draft guidance documents under review by the American Society for Testing and Materials (ASTM). A 

standard method for the analysis of surface water and wastewater is anticipated to be complete by 2012. 

Current practices of sample analysis are on a project basis (see Zaugg et al. 2006), which provide for 

quantifying concentrations of total NPEO1, NPEO2 and 4- NP. 

Table 1. Acute toxicity values considered in development of numeric aquatic life standards. Notes: n – not 

used for standard development: (marine) – marine species; (short test) – test length unacceptable; (chemical) 

– exposure chemical not reported or unacceptable; (non-native) – not native species; (methods) – 

unacceptable methods used. ACR – data used to calculate acute to chronic ratio. 

Species Scientific Name Endpoint 

Conc. (ug/L) 

Chemical 

exposure 

 Author Notes 

Acipenser oxyrhynchus 80 4 - NP Dwyer et al. 2000 n (marine) 

Acipenser oxyrhynchus 80 4 - NP Dwyer et al. 2000 n (marine) 

Alosa sapidissima 50 4 - NP Dwyer et al. 2000 n (short test) 

Bufo boreas 120 4 - NP Dwyer et al. 1999 y 

Ceriodaphnia 210 NPEO Isidori et al. 2006 y; ACR 

Ceriodaphnia 220 NPEO Isidori et al. 2006 y; ACR 

Ceriodaphnia 70 NPEO Isidori et al. 2006 n (chemical) 

Ceriodaphnia 92.4 NPEO TenEcyck and Markee 2007 y 

Ceriodaphnia 328 NPEO TenEcyck and Markee 2007 y 

Ceriodaphnia 716 NPEO TenEcyck and Markee 2007 y 

Chironomus 160 4 -NP England 1993 y 

Crinia insignifera 6400 NPEO Mann and Bidwell 2000 n (non-native) 

Crinia insignifera 4500 NPEO Mann and Bidwell 2000 n (non-native) 

Daphnia magna 104 4 - NP Brooke 1993 y; ACR 

Daphnia magna 190 4 - NP Comber 1993 y; ACR 

Daphnia magna 180 4 -NP Hirano et al. 2004 y 

Etheostoma 190 4 - NP Dwyer 1999 y 

Etheostoma 110 4 - NP Dwyer 1999 y 

Etheostoma lepidum 220 4 - NP Dwyer et al. 1999 y 

Etheostoma lepidum 200 4 - NP Dwyer et al. 1999 y 

Etheostoma lepidum 190 4 - NP Dwyer et al. 1999 y 

Etheostoma rubrum 110 4 - NP Dwyer et al. 1999 y 

Etheostoma rubrum 170 4 - NP Dwyer et al. 1999 y 

Etheostoma rubrum 130 4 - NP Dwyer et al. 1999 y 

Gila elegans 310 4 - NP Dwyer 1995 y 

Gila elegans 270 4 - NP Dwyer 1995 y 

Gila elegans 290 Sappington et al. 2001 y 

Hyallela 20.7 4 - NP Brooke 1993 y 

Hyallela 150 4 -NP England 1995 y 

L. variegatus 342 4 - NP Brooke 1993 y 

Lampsilis cardium 1190 4 -NP Milam et al. 2005 n (methods) 

Lampsilis siliquoidea 490 4 -NP Milam et al. 2005 n (methods) 

Lepomis 209 4 - NP Brooke 1993 y 

Leptodea fragilis 570 4 -NP Milam et al. 2005 n (methods) 

11 
Ligumia subrostrata 1040 4 -NP Milam et al. 2005 n (methods) 

Litoria adelaidensis 9200 NPEO Mann and Bidwell 2000 n (non-native) 

Litoria adelaidensis 8800 NPEO Mann and Bidwell 2000 n (non-native) 

Litoria adelaidensis 8800 NPEO Mann and Bidwell 2000 n (non-native) 

Megalonaias nervosa 560 4 -NP Milam et al. 2005 n (methods) 

Onchorhynchus 221 4 - NP Brooke 1993 y; ACR 

Onchorhynchus 190 4 - NP Dwyer 1995 y 

Onchorhynchus 260 4 - NP Dwyer 1995 y 

Onchorhynchus 140 4 - NP Dwyer 1995 y 

Onchorhynchus 270 4 - NP Dwyer 1995 y 

Species Scientific Name Endpoint 

Conc. (ug/L) 

Chemical 

exposure 

 Author Notes 

Onchorhynchus 180 4 - NP Dwyer 1995 y 

Onchorhynchus 180 4 - NP Dwyer 1995 y 

Onchorhynchus 160 4 - NP Dwyer 1995 y 

Onchorhynchus 150 4 - NP Dwyer 1995 y 

Onchorhynchus 140 4 - NP Dwyer 1995 y 

Onchorhynchus 220 4 - NP Dwyer 1995 y 

Oncorhynchus clarkii stomias 150 Sappington et al. 2001 y 

Oncorhynchus gilae apache 170 Sappington et al. 2001 y 

Oncorhynchus mykiss 190 Sappington et al. 2001 y 

Ophiogomphus 596 4 - NP Brooke 1993 y 

Oryzias latipes 870 4 - NP Kashiwada et al. 2002 n (test spp.) 

Oryzias latipes 850 4 - NP Kashiwada et al. 2002 n (test spp.) 

Oryzias latipes 130 4 - NP Kashiwada et al. 2002 n (test spp.) 

Oryzias latipes 850 4 - NP Kashiwada et al. 2002 n (test spp.) 

Physella 774 4 - NP Brooke 1993 y 

Pimephales promelas 128 4 - NP Brooke 1993 y 

Pimephales promelas 210 4 - NP Dwyer 1995 y 

Pimephales promelas 360 4 - NP Dwyer 1995 y 

Pimephales promelas 310 4 - NP Dwyer 1995 y 

Pimephales promelas 330 4 - NP Dwyer 1995 y 

Pimephales promelas 170 4 - NP Dwyer 1995 y 

Pimephales promelas 290 4 - NP Dwyer 1995 y 

Pimephales promelas 140 4 -NP Holcombe et al. 1984 y 

Pimephales promelas 270 Sappington et al. 2001 y 

Pimephales promelas 323 NPEO TenEcyck and Markee 2007 y 

Pimephales promelas 136 NPEO TenEcyck and Markee 2007 y 

Pimephales promelas 218 NPEO TenEcyck and Markee 2007 y 

Poeciliopsis occidentalis 250 4 - NP Dwyer et al. 1999 y 

Poeciliopsis occidentalis 250 4 - NP Dwyer et al. 1999 y 

Poeciliopsis occidentalis 230 4 - NP Dwyer et al. 1999 y 

Ptychocheilus lucius 270 4 - NP Dwyer 1995 y 

Ptychocheilus lucius 240 4 - NP Dwyer 1995 y 

Ptychocheilus lucius 260 Sappington et al. 2001 y 

Rana sphenocephala 340 4- NP Bridges et al. 2002 y 

Scaphirhynchus platorynchus 200 4 - NP Dwyer et al. 1999 n (short test) 

Scaphirhynchus platorynchus 130 4 - NP Dwyer et al. 1999 n (short test) 

Scaphirhynchus platorynchus 130 4 - NP Dwyer et al. 1999 y 

Thamnocephalus platyurus 4.82 NP form Brausch and Smith 2007 n (chemical) 

Thamnocephalus platyurus 2.6 NP form Brausch and Smith 2007 n (chemical) 

Thamnocephalus platyurus 3.68 NP form Brausch and Smith 2007 n (chemical) 

Utterbackia imbecilis 770 4 -NP Milam et al. 2005 y 

12 
Xenopus laevis 5400 NPEO Mann and Bidwell 2000 y 

Xenopus laevis 2800 NPEO Mann and Bidwell 2000 y 

Xenopus laevis 3300 NPEO Mann and Bidwell 2000 y 

Xenopus laevis 4600 NPEO Mann and Bidwell 2000 y 

Xenopus laevis 3900 NPEO Mann and Bidwell 2000 y 

Xenopus laevis 4600 NPEO Mann and Bidwell 2000 y 

Xenopus laevis 4800 NPEO Mann and Bidwell 2000 y 

Xiphophorus helleri 205.98 Kwak et al. 2001 y 

Xyrauchen texanus 190 4 - NP Dwyer 1995 y 

Xyrauchen texanus 160 4 - NP Dwyer 1995 y 

Xyrauchen texanus 170 Sappington et al. 2001 y 

 

13 
Table 2. Calculations of aquatic life numeric standard for 4-NP, NP1EO and NP2EO. 

Genus name GMAV Rank P ACR

Xenopus 4108.6 18

Physella 774.0 17

Ophiogomphus 596.0 16

Lumbriculus 342.0 15

Rana 340.0 14

Gila 289.5 13

Ptychocheilus 256.4 12

Ceriodaphnia 251.3 11 9.08

Pimephales 225.9 10

Lepomis 209.0 9

Onchorhynchus 181.4 8 28.11

Xyrauchen 172.9 7

Chironomus 160.0 6

Etheostoma 159.8 5 0.26

Daphnia 152.6 4 0.21 2.02

Scaphirhynchus 130.0 3 0.16

Bufo 120.0 2 0.11

Hyallela 55.7 1 0.05

GMAV P ln GMAV (ln GMAV) Sq Rt P

Daphnia magna 152.6 0.21 5.0281 25.2820 0.4588

Scaphirhynchus plato 130.0 0.16 4.8675 23.6929 0.3974

Bufo boreas 120.0 0.11 4.7875 22.9201 0.3244

Hyallela azteca 55.7 0.05 4.0204 16.1635 0.2294

Genus ACR

s2 Num 0.6029 Ceriodaphnia 9.08

s2 Denom 0.0293 Onchorhynchus 28.11

S2 20.6093 Daphnia 2.02

Sqrt S2 4.5397 Mysis 8.40

L 3.0756

A 4.0907

FAV 59.7808

GeoMean 

CC: Chronic Calc(Mysis) 7.1 ACR (Mysis; EPA Crit.) 8.40

CC: Chronic Calc #1 7.5 ACR (RBT, D.m., C.d., Mysis): 7.95

CC (2A Salmonid): 2.1 ACR (2A salmonid): 28.11

CC (FW ACR): 7.5 ACR FW (RBT, C.d., D.m.) 8.02

 

14 
MINNESOTA POLLUTION CONTROL AGENCY 

DRAFT AQUATIC LIFE NUMERIC STANDARD SUMMARY SHEETS 

Table 3 Draft Water Quality Standards 

A. Chemical: Nonylphenol ethoxylates CAS# Date January 2010

B. Minnesota Criterion: ug/l (unless noted otherwise) 

Water Class Use CS MS FAV Basis2

1,2A DW, Salmonid 2.4 30 59.78 PCAT1 

1,2Bd DW, NonSalmonid 7.4 30 59.78 PCAT1 

2B, 2C, 2D NonSalmonid 7.4 30 59.78 PCAT1 

Other Round to 60 

Are Minnesota numeric standards modified from existing EPA criteria? Yes 

Is toxicity related to water quality characteristic?: No

If yes, above standard values determined for: 

Slope: Acute: 

 Chronic: 

Formulas: MPCA EPA

CS: 

MS: 

FAV: 

Notes: Chronic criteria lowered for 2A waters to protect Rainbow Trout 

C. EPA Criterion: ug/l 

Date: Dec 2005 CCC: 6.6 Basis: EPA T1 (4- nonylphenol) 

 MC: 28 Basis: EPA T1 (4- nonylphenol) 

FAV: 55.49 Basis: EPA T1 (4- nonylphenol) 

D. Other Criteria ug/l Source

E. Notes: U.S. EPA Aquatic Life for Nonylphenol available at: 

www.epa.gov/waterscience/criteria/nonylphenol 

 

2

 Criteria basis codes for part B: 

EPA = From EPA criterion 

PCA = Criterion developed by Minnesota Pollution Control Agency staff 

T1 = Direct aquatic life toxicity, EPA national criteria procedures used 

T2 = Direct aquatic life toxicity, EPA advisory procedures used 

Hs = Human health systemic effects 

Hc = Human health carcinogenic effects 

R = Tissue residue (bioaccumulation) 

W = Wildlife effects 

O = Organoleptic (taste and odor) 

Other = Criterion based on other end point 

15 
MINNESOTA POLLUTION CONTROL AGENCY 

DRAFT AQUATIC LIFE NUMERIC STANDARD

Determination of Numeric Standard from Aquatic Life Toxicity Values 

A. Chemical: Nonylphenol ethoxylates CAS# Date January 2010

B. EPA National Method 

1. Data 

requirements: 

Salmonid (2A water only): Onchorhynchus 

Osteichthyes (fish): Scaphirhynchus, Pimephales 

Chordata (fish, amphibian): Bufo, Rana. 

Planktonic crustacean: Daphnia, Ceriodaphnia 

Benthic crustacean: Hyalella azteca 

Aquatic insect: Chironomus, Ophiogomphus. 

Phylum other than Arthropoda or 

Chordata: 

Physella 

Second insect or phylum not already rep.: Lumbriculus 

2. GMAVs Lowest 4(2A): 152.65 (Daphnia magna) Lowest 4(2B,2C, 2D): same 

 ug/l 130.0 (Scaphirhynchus platorynchus) same 

N: 23 120.0 (Bufo boreas) N: same 

 55.7 (Hyalella azteca) same 

3. FAV: 2A: 59.78 2B, 2C, 2D: 59.78 

4. Adjustments to FAVs: None 

5. Chronic data: No. Species: 

mean values 

6. ACR Measured: Acute value Chronic value ACR 

Ceriodaphnia 214.94 23.66 9.083 

Onchorhynchus 221 7.861 28.11 

Daphnia (Geomean) 140.57 69.50 2.023 

GeoMean ACR: 7.795 

Note: Onchorhynchus ACR (28.11) used 

for class 2A chronic criterion 

calculation. 

7. Final Plant Value: Not Determined

C. EPA Advisory Method Not Determined

D. Notes: Nonyphenol ethoxylates are described as combined aqueous concentrations of 4-nonylphenol, 

nonylphenol mono-ethoxylate (NP1EO) and nonylphenol di-ethoxylate (NP2EO).

16 
MINNESOTA POLLUTION CONTROL AGENCY 

DRAFT AQUATIC LIFE NUMERIC STANDARD

HUMAN HEALTH – To Be Determined 

A. Chemical: Nonylphenol ethoxylates CAS# Date 30 June 2009 

B. EPA Human Health Criterion: DW and fish: none fish only: none DW only: none 

ug/l 

ADI/Ref.dose: mg/kg/day Cancer Potency Slope: (mg/kg-d)-1 

Final BCF: %lipid: 

RSC: 

C. Minnesota Human Health Criterion 

1. Ref.dose: mg/kg/day Source: 

 RSC: Source: 

2. Cancer Potency Slope: (mg/kg-d)-1 Source: 

3. Measured BAFs: Species/Tissue BAF %lipid Norm BAF 

 1. 

 2. 

 Geo mean: 

4. Measured BCFs: Species/Tissue BCF %lipid Norm. BCF 

 1. 

 2. 

 Geo mean: 

5. Edible portion BAF or BCF BAF BCF 

 Cold water: 6.0 % lipid 

 Warm water: 1.5 % lipid 

6. Geo mean unadjusted for lipid: 

 

7. log Kow: 

 adjust. for % lipid: 

meas. 

 

QSAR: Est. BCF: 

 

8. Parachor: 

9. Food Chain Multiplier: 

10. Final BAF: 2A: 2B,2C, 2D: 

11. Criteria: ug/l 2A: 2Bd: 2B/2C, 2D: HRL/HBV: 

D. Organoleptic: ug/l Source: 

E. Notes: Sufficiently reviewed human health toxicological values were not available from U.S. EPA’s 

Integrated Risk Information System or Minnesota Department of Health (MDH 2009) to develop a human 

health-based CS. EPA’s 304 (a) AWQC also did not provide final recommended national bioaccumulation 

factors. 

17 
Figure A. Data summarized from US EPA (2005), Table 6 as plotted using a species sensitivity distribution 

performed by CADDIS (US EPA 2000). 

Atl. Salmon

D. galeata

Clawed frog

zooplankton/

benthic macs

D. magna

Duckweed

Bluegill

Platyfish

moss

Swordtail

FHM

Carp

RBT

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0.10 1.00 10.00 100.00 1000.00 10000.00

Proportion of species affected 

Micrograms NPEO per liter

Represents 5% or less of reported chronic values for aquatic species.

Taxa 

Micrograms 

NPEO per 

liter 

Standard 

Deviation 

Proportion 

Taxa 

Number of 

Observations 

Swordtail 0.20 4% 1 

FHM 2.88 0.17 11% 4 

Carp 10.00 18% 2 

RBT 18.80 0.73 25% 18 

Atl. Salmon 20.00 32% 1 

D. galeata 22.40 39% 1 

Clawed frog 27.87 0.15 46% 2 

zooplankton 41.80 54% 1 

benthmacs 41.80 54% 1 

D. magna 54.14 0.11 68% 3 

Duckweed 125.00 75% 1 

Bluegill 135.90 82% 1 

Platyfish 960.00 89% 1 

moss 2500.00 96% 1 

Plotted data summarized from EPA 2005, Table 6. 

18 
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