Page 1 of 76

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

`

March 6, 2016

PC Codes: 056502

MEMORANDUM DP Barcode: D429797

SUBJECT: Registration Review: Preliminary Problem Formulation for Environmental Fate, 

Ecological Risk, Endangered Species, and Human Health Drinking Water 

Exposure Assessments for Pentachloronitrobenzene (PCNB)

FROM: Jim Carleton, Ph.D., Senior Fate Scientist

Thomas Steeger, Ph.D., Senior Science Advisor

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

REVIEWED 

BY: Cheryl Sutton, Ph.D., Environmental Scientist

Catherine Aubee, Senior Biologist

Katrina White, Ph.D., Risk Assessment Process Leader

THROUGH: Jean Holmes, D.V.M., Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507P)

TO: Veronica Dutch, Chemical Review Manager

Jill Bloom, Team Leader

Risk Management and Implementation Branch V

Pesticide Re-evaluation Division (7508P)

1. Executive summary

The Environmental Fate and Effects Division (EFED) has completed the preliminary problem 

formulation for the ecological risk, environmental fate, endangered species, and drinking water 

assessments to be conducted as part of the Registration Review of pentachloronitrobenzene (PCNB; 

CAS No. 82-68-8; PC Code 056502). The Registration Review considers existing uses of PCNB

as a contact fungicide via soil and seed treatment as well as via foliar applications. The available 

environmental fate data for PCNB indicate that the compound is persistent and moderately volatile.

Although PCNB is not considered to be mobile, it nevertheless has the potential to leach into 

groundwater in sandy soils, and to move into surface water through runoff, particularly in the form 

of residues sorbed to mobilized sediment (i.e., erosion), as well as via spray drift. As with other 

chlorinated benzenes with moderate volatility, PCNB can also move to areas distant from use sites 

via long-range atmospheric transport. The compound is subject to aqueous photolysis and, to a 

lesser extent, microbially-mediated degradation, including under anaerobic conditions. Degradates
Page 2 of 76

of concern include: pentachloroaniline (PCA), pentachlorothioanisole (PCTA), 

pentachlorothioanisole sulfoxide (PCTASO), pentachlorothioanisole sulfone (PCTASO2), 

pentachlorophenol (PCP) and pentachlorobenzene (PCB), all of which are structurally similar to 

the parent and expected to be persistent.

This problem formulation describes the methods planned to be used during the completion of 

drinking water and ecological risk assessments in support of Registration Review, and provides an 

overview of the environmental fate, ecological effects, and potential risks associated with the usage 

of PCNB, as well as sources of uncertainty. This document also identifies additional studies that 

would address uncertainties in assessing ecological risk associated with current uses of PCNB. The 

risk assessment will consider not only parent PCNB, but also degradates that have been identified 

as residues of ecotoxicological concern (PCA, PCTA, PCTASO, PCTASO2, PCP, PCB) in previous 

assessments1, and manufacturing by-products of concern including hexachlorobenzene (HCB), 

pentachlorobenzene (PCB - both a manufacturing by-product and a degradate), and congeners 

(structurally related chemicals) of polychlorinated dibenzo-p-dioxins/dibenzofurans 

(dioxins/furans).

The fate database is incomplete based on the environmental fate data requirements outlined in the 

Code of Federal Regulations Title 40 Part 158 (40CFR158) Subpart N2and uncertainties discussed 

in the environmental fate and ecological risk assessment3 written in support of the Reregistration

Eligibility Decision (RED)4. In 2009, EFED completed a post-RED data call-in justification for 

PCNB (DP Barcode D291273) in which multiple studies were identified. Data needs have again 

been considered, based on current scientific understanding and Agency policy, and the data that are 

now recommended to be required differ somewhat from those identified in 2009. With respect to 

environmental fate, the following studies are recommended: 

 Photodegradation in Water (PCNB TGAI) (Guideline 835.2240)

 Photodegradation in Water (PCA) (Guideline 835.2240)

 Photodegradation in Air (PCNB TGAI) (Guideline 835.2370)

 Photodegradation in Air (PCA) (Guideline 835.2370)

 Aerobic Soil Metabolism (PCNB TGAI) (Guideline 835.4100)

 Anaerobic Soil Metabolism (PCNB TGAI) (Guideline 835.4200)

 Aerobic Aquatic Metabolism (PCNB TGAI) (Guideline 835.4300)

 Anaerobic Aquatic Metabolism (PCNB TGAI) (Guideline 835.4400)

 Foliar Dissipation (PCNB TEP) (Guideline 835.6100SS; Special Study)

 ECM/ILV for Water (PCNB) (Guideline 850.6200)

 

1 USEPA. 2012. Risks of Pentachloronitrobenzene Use to the Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha

bayensis), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt 

(Hypomesus transpacificus) and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater 

Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and 

Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia) and Tidewater Goby 

(Eucyclogobius newberryi) Pesticide Effects Determinations. PC Code 056502. June 28, 2012. 

http://www3.epa.gov/pesticides/endanger/litstatus/effects/redlegfrog/2012/pcnb/assessment.pdf#_ga=1.190689199.520862732.1416572410

2 CFR. 2015. Title 40 (Protection of the Environment), Chapter 1 (Environmental Protection Agency), Subchapter E (Pesticide

Programs), Part 158 (Data Requirements for Pesticides), Subpart N (Environmental Fate) http://www.ecfr.gov/cgi-bin/textidx?c=ecfr&SID=ff5c7fef3645e7cd5abceca0b597bccb&tpl=/ecfrbrowse/Title40/40cfr158_main_02.tpl

3 USEPA. 2005. Revised Environmental Fate and Ecological Risk assessment of Pentachloronitrobenzene (PCNB) dated February 15, 

2005. DP Barcode D291276.

4 USEPA. 2006. Reregistration Eligibility Decision for Pentachloronitrobenzene List A Case No. 0128. Office of Chemical Safety and 

Pollution Prevention (formerly the Office of Prevention, Pesticides and Toxic Substances). July 11, 2006. Available on-line at: 

http://archive.epa.gov/pesticides/reregistration/web/pdf/pcnb_red.pdf or http://www.regulations.gov/#!documentDetail;D=EPA-HQOPP-2004-0202-0057.
Page 3 of 76

 ECM/ILV for Soil (PCNB) (Guideline 850.6100)

 ECM/ILV for Sediment (PCNB) (Guideline 850.6100)

Studies are recommended primarily for PCNB, however it should be noted that two studies are also 

recommended for PCA because PCA formed at the highest relative percentage (up to 86.6% of 

applied radioactivity) of any PCNB degradate identified in the currently available fate studies, and 

in those studies appears to be persistent. Photolytic studies on PCA are recommended in particular 

because aqueous photolysis represents a relatively rapid degradation pathway for parent PCNB, yet 

the products of photolytic degradation of PCNB have not been identified. If photolysis proves to 

be a similarly important degradation route for PCA, then adequate identification of the 

photodegradates of PCA will be important for understanding the risks posed by PCNB usage. 

Anaerobic aquatic data are recommended to be required because no fully acceptable aquatic data 

(aerobic or anaerobic) have yet been submitted. Additional anaerobic soil data are also required 

because the available data were determined to be supplemental only, and these previously

submitted data are the only fate data in which PCP has appeared as a degradate. EPA needs to 

better understand the significance of this pathway.

With respect to the special study of PCNB foliar dissipation, the study should include relevant 

environmental chemistry methods (ECM) for soil, water and sediment with independent laboratory 

validation (ILV). 

The ecological database is also incomplete based on the ecological effects data requirements 

outlined in the 40CFR Part 158 Subpart G5and uncertainties discussed in the environmental fate 

and ecological risk assessment (USEPA 20056) written in support of the RED (USEPA 2006

7

) and 

more recent guidance on assessing risks to bees. The data that are now recommended to be required 

differ somewhat from those identified in the RED. Additional toxicity data on the following taxa 

are recommended for PCNB: 

 Terrestrial plant toxicity data, Tier I/Tier II (Seedling Emergence and 

Vegetative Vigor) (PCNB TEP) (Guidelines 850.4100 and 850.4150)

 Aquatic plant toxicity data (PCNB TGAI) (Guidelines 850.4400 and 850.5400)

 Estuarine/marine fish life cycle (PCNB TGAI)

 Estuarine/marine invertebrate life cycle (PCNB (TGAI) (Guideline 850.1350)

 Whole sediment (PCNB TGAI) (Guidelines 850.1735 and 850.1740; three benthic 

species.)

 Whole sediment; chronic (PCNB TGAI) (Special Study)

 Acute toxicity freshwater fish (PCA; two species) (Guideline 850.1075)

 Acute toxicity estuarine/marine fish (PCA) (Guideline 850.1075)

 Mysid Acute Toxicity (PCA) (Guideline 850.1035)

 Acute toxicity – freshwater invertebrates (PCA) (Guideline 850.1010)

 Fish early life stage – freshwater (PCA) (Guideline 850.1400)

 Fish full life cycle—freshwater (PCNB) (Guideline 850.1500)**

 Aquatic invertebrate life cycle (freshwater) (PCA) (Guideline 850.1300)

 Aquatic Food Chain Transfer (Guideline 850.1850)

 Avian acute oral toxicity – passerine (PCNB TGAI) (Guideline 850.2100)

 

5 CFR. 2015. Title 40 (Protection of the Environment), Chapter 1 (Environmental Protection Agency), Subchapter E (Pesticide 

Programs), Part 158 (Data Requirements for Pesticides), Subpart G (Ecological Effects) http://www.ecfr.gov/cgi-bin/textidx?SID=184ddf1c19b82301b18d48a454a60c6d&mc=true&node=sp40.24.158.g&rgn=div6

6

Ibid USEPA. 2005.

7

Ibid USEPA. 2006. 
Page 4 of 76

 Pollinator toxicity data consisting of:

o acute oral test with adult honey bees (PCNB TGAI) (OECD 213);

o acute honey bee larvae test (PCNB TGAI) (OECD 237); 

o 10-day adult honey bee test (PCNB TGAI) (draft OECD guideline); and,

o 21-day larval honey bee toxicity test (PCNB TGAI) (draft OECD guidance)

o Semi-field whole colony test (PCNB TEP) (OECD 75)*

o Full-field whole colony test (PCNB TEP) (850.3040)*

o Residues in pollen/nectar* (TEP; non-guideline)

*pending outcome of lower-tier pollinator studies

**fish full life cycle study can be waived pending successful completion of medaka 

extended one generation test (MEOGRT; Guideline 890.2200)

2. Introduction

PCNB (1,2,3,4,5-pentachloro-6-nitrobenzene, or quintozene; CAS No.: 82-68-8) is an 

organochlorine (i.e., chlorinated benzene) contact fungicide first registered in the United States in 

1964 that is intended to provide preventative and residual protection against soil-borne fungal 

diseases. The chemical acts through inhibition of hyphal growth in fungi by means of competitive 

inhibition of inositol.

PCNB was last assessed nationally in 2005 for the Reregistration Eligibility Decision (USEPA 

2006

8

) although a more recent assessment for specific Federally listed threatened/endangered 

species in California9 was conducted in 2012. No new uses have been assessed since that time; 

however, multiple uses were cancelled subsequently. EFED considered the most recent ecological 

risk assessment for PCNB in association with any available updated toxicity, exposure, and usage 

information to determine if sufficient data are available or if further updates are needed to support 

Registration Review. EFED has also considered the latest Agency science policies and risk 

assessment methodologies in compiling this problem formulation. 

3. Use Characterization

PCNB is an active ingredient registered for the control of fungal diseases on agricultural crops, 

ornamental plants, bulbs, and turf. According to a screening-level assessment of PCNB uses 

conducted by the Biological and Economic Analysis Division, the average number of pounds of 

active ingredient applied annually to agricultural crops during the reporting period of 2004 – 2013, 

was approximately 324,500 lbs. This is reduced from the average reported by the USGS (887,548 

lbs) for 1999 to 2004. The majority of agricultural usage from 2004 – 2013 was on potatoes, cotton 

and green beans which represented 61%, 18% and 6% of total agricultural usage, respectively. 

USGS-estimated average agricultural usage by year and crop for PCNB is depicted in Figure 1 and 

indicates a relatively steady decline in use from 1994 to 2012. Although agricultural use is depicted 

as declining, non-agricultural use (e.g., turf, sod farms) is not included in these estimates and the 

 

8

Ibid USEPA. 2006.. 

9 USEPA. 2012. Risks of Pentachloronitrobenzene Use to the Federally Threatened Bay Checkerspot Butterfly (Euphydryas editha 

bayensis), California Tiger Salamander (Ambystoma californiense), Central California Distinct Population Segment, and Delta Smelt 

(Hypomesus transpacificus) and the Federally Endangered California Clapper Rail (Rallus longirostris obsoletus), California Freshwater 

Shrimp (Syncaris pacificus), California Tiger Salamander (Ambystoma californiense) Sonoma County Distinct Population Segment and 

Santa Barbara County Distinct Population Segment, San Francisco Garter Snake (Thamnophis sirtalis tetrataenia) and Tidewater Goby 

(Eucyclogobius newberryi) Pesticide Effects Determinations. PC Code 056502. June 28, 2012. 

http://www3.epa.gov/pesticides/endanger/litstatus/effects/redlegfrog/2012/pcnb/assessment.pdf#_ga=1.190689199.520862732.1416572410
Page 5 of 76

general decline may not apply. However, in July 2009, certain residential and other uses were 

cancelled, so a reduction in usage on non-agricultural sites would not be unexpected. Later use 

terminations and the execution of a stop-sale order may have impacted overall usage as well.

Figure 1. PCNB estimated agricultural use (in millions of pounds) by year and crop 

(USGS Pesticide National Synthesis Project

https://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2012&map=QUINTO

ZENE&hilo=L&disp=Quintozene)

PCNB is formulated as a flowable concentrate and as a granule. The maximum single application 

rate for ornamentals equates to roughly 213.4 pounds of active ingredient per acre (lbs a.i./A).

There are formulations of PCNB containing other active ingredients (e.g., metalaxyl10, 

chlorothalonil11 and propioconazole

12). Historically, PCNB has commonly been used in 

combination with insecticides and other fungicides (e.g., carbaryl, imazalil, triadimenol, 

fuberidazole), particularly for soil applications to cotton (e.g., with etridiazole, disulfoton, and 

phorate), turf, potato, and peanuts (e.g., with ethoprop); and for seed treatment applications (e.g., 

with captan, carboxin, metalaxyl, TBZ, and Bacillus subtilis; PCNB is no longer registered for seed 

treatment). 

Application methods that are used in the field include broadcast or row drench, pre-emergent 

broadcast, row spray, in-furrow (spray and granular), furrow, foliar spray, band, transplant solution, 

and chemigation. Applications of PCNB are typically made only once a season, although the labels 

allow for repeat applications for some uses, such as turf. PCNB may be applied at seed planting, a 

pre-emergent, at planting or transplant, or as a post-emergent (either at mid-season for beans, 

peanuts, potatoes or ornamentals; or at the first appearance of disease on turf).

On November 23, 2011, the Agency approved a request by the sole technical registrant of PCNB

(i.e., Amvac) that resulted in the following amendment to the terms and conditions of its PCNB

registrations: 

 

10 Ridomil gold PC GR®

(EPA Reg No. 100-823)

11 Andersons 3-day Snow Mold Fungicide®

(EPA Reg No. 9198-227)

12 Andersons 3-day Snow Mold Fungicide®

(EPA Reg No. 9198-227)
Page 6 of 76

 Amvac agreed not to sell, distribute, or formulate any Technical Grade PCNB (EPA Reg. 

# 5481-197) with concentrations of dioxins/furans greater than a particular limit. Amvac 

agreed to report the results of its analyses of the technical material.

 The technical registrant agreed to market only three PCNB products (labeled to conform 

to the other elements of the approved amendments)--technical grade PCNB, Turfcide®10% 

Granular (Reg. # 5481-8988) and Turfcide®4F (Reg. # 5481-8992). 

 The technical registrant agreed to request cancellation of all non-liquid/non-granular 

registrations of PCNB.

The Biological and Economic Analysis Division (BEAD) lists the uses associated with active 

registrations of PCNB. EFED will rely on the data from BEAD when estimating environmental 

exposures that result from these registered uses. Additionally, in order to be protective, EFED will 

utilize the use information that results in maximum exposure (e.g., concentration) estimates for a 

given use pattern for the drinking water and ecological risk assessments. If the labels (and 

consequently the BEAD chemical profile) do not include all information needed to enable 

estimation of maximal exposures, EFED will make conservative assumptions regarding these use 

parameters. 

4. Conclusions from Previous Risk Assessments

a. Ecological Risk Assessment 

In 2005, EPA completed an environmental fate and ecological risk assessment of PCNB13 in 

support of the Reregistration Eligibility Decision. Based on that screening-level risk assessment for 

the use of PCNB at maximum application rates, on use sites for which it was registered at the time,

chronic risk to terrestrial animals (birds, reptiles, terrestrial-phase amphibian, and mammals) and 

both acute and chronic risks to aquatic animals (fish, aquatic-phase amphibian and invertebrates) 

were identified. Although PCNB is slightly mobile (based on United Nations Food and Agriculture 

Organization mobility classification scheme) in most soils, the chemical and its degradates are 

sufficiently persistent to possibly result in environmental concentrations similar to those that have, 

in laboratory studies, resulted in adverse effects to non-target animals. PCNB and its degradates 

were expected to bioconcentrate; thus, environmental concentrations can accumulate in the tissues 

of exposed organisms to levels at which effects are more likely. Additionally, the assessment noted 

that the effects of PCNB may not be limited to organisms in close proximity to PCNB usage since 

the chemical is also subject to long-range atmospheric transport. In the absence of data (e.g., 

terrestrial and aquatic plants), the potential risk is uncertain.

b. Assessment of Bioaccumulation and Long-Range Transport Potential of 

PCNB (PCNB) and Associated Risks

In 2010, EPA completed an assessment14 (DP Barcode D291271) of the bioaccumulation and longrange transport potential of PCNB, including its degradates and contaminants based on input from 

 

13 Ibid USEPA. 2005. 

14 K. Garber, 3/22/10, “2008 Science Advisory Panel Meeting Follow Up: Assessment of the Bioaccumulation and Long-Range 

Transport Potential (LRTP) and of Pentachloronitrobenzene (PCNB) and Associated Ecological Risks” can be found at 

http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2004-0202-0265.
Page 7 of 76

a FIFRA Scientific Advisory Panel in 200815 on an EFED White Paper16 concerning methods for 

assessing ecological risks of pesticides with persistent, bioaccumulative and toxic characteristics. 

The assessment concluded that PCNB, its degradates and its contaminants were sufficiently 

persistent and likely to bioaccumulate in aquatic food chains to constitute a chronic risk to 

mammals and birds that consume aquatic organisms. Also, PCNB was expected to move 

considerable distances from its site of application through long-range atmospheric transport. As 

discussed in the assessment, PCNB contains several contaminants, including hexachlorobenzene, 

polychlorinated dibenzodioxins and polychlorinated dibenzofurans, which are listed under the 

Stockholm Convention as Persistent Organic Pollutants (POPs), and the weight of evidence 

suggested that PCNB, when considered with its residues and contaminants of concern, is a 

persistent, bioaccumulative, toxic chemical (PBT). 

c. Risk Conclusions from OPP’s previous PCNB Federally listed Species Effect 

Determination

In 2012, EPA completed an effects determination17 for PCNB on multiple Federally listed 

threatened and endangered species for marketed uses of PCNB on cole crops, cotton, potatoes and 

turf in California. Although not considered in the 2005 ecological risk assessment chapter for the 

PCNB RED (because at the time of that document’s writing EPA was unaware of their presence), 

polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) present in 

PCNB formulations as contaminants were considered to be of concern in the effects determination 

since they are persistent, bioaccumulative and not readily metabolized by mammals and would be 

expected to bioaccumulate to a greater extent than PCNB. EPA made a likely to adversely affect 

(LAA) determination for each of the species evaluated and also determined that there was a 

potential for modification of the designated critical habitat for the Bay checkerspot butterfly 

(Euphydryas editha bayensis), Delta smelt (Hypomesus transpacificus), tidewater goby 

(Eucyclogobius newberryi), and the Central California distinct population segment and the Santa 

Barbara County distinct population segment of the California tiger salamander (Ambystoma 

californiense). 

The major environmental fate and ecological risk conclusions identified in previous assessments 

are summarized in Table and 2.

Table 1. Potential fate concerns identified in previous assessments for PCNB.

Bioconcentration/ 

Bioaccumulation1

Groundwater 

Contamination2

Presence in 

Sediment Persistence Residues of Concern Volatilization

Yes Yes Yes Yes

PCNB, PCA, 

PCTA, PCTASO, 

PCTASO2, PCP 

PCB, HCB

Yes

Abbreviations: pentachlorothioanisole (PCTA), pentachlorothioanisole sulfoxide (PCTASO), pentachlorothioanisole sulfone 

(PCTASO2), pentachlorophenol (PCP) and pentachlorobenzene (PCB) 

1 Based Aquatic Bioaccumulation Model (KABAM) for chemicals with log Kow >3.

2 Sandy soils.

 

15 SAP. 2008. FIFRA Scientific Advisory Panel Meeting. Selected Issues Associated with the Risk Assessment Process for Pesticides 

with Persistent, Bioaccumulative, and Toxic Characteristics. October 28 – 31, 2008. Meeting materials and minutes are available online at: http://archive.epa.gov/scipoly/sap/meetings/web/html/index-13.html

16USEPA. 2008b. White paper on methods for assessing ecological risks of pesticides with persistent, bioaccumulative and toxic 

characteristics. Submitted to the FIFRA Scientific Advisory Panel for review and comment. United States Environmental Protection 

Agency, Environmental Fate and Effects Division. Available online at: 

http://www.epa.gov/scipoly/sap/meetings/2008/october/sap_pbt_whitepaper_final_Oct_7_08d.pdf.

17 Ibid USEPA. 2012. 
Page 8 of 76

Table 2. Potential for direct effects identified in previous assessments for PCNB.1

Listed/or 

nonlistedBirds2 Mammals Terrestrial

Invertebrates

Aquatic 

Vertebrates3

Aquatic 

Invertebrates

Terrestrial

Plants

Aquatic 

Plants

Nonlisted Yes Yes Presumed4 No No UNC5 UNC5

Listed Yes Yes Presumed4 Yes Yes UNC5 UNC5

1 Risk concerns were identified when the RQ exceeded the corresponding level of concern in a previous risk assessment or 

were identified as a potential concern based on weight of evidence.

2 Birds serve as surrogates for terrestrial-phase amphibians and reptiles.

3 Fish serve as surrogates for aquatic-phase amphibians.

4 Toxicity data not available, risk presumed.

5 UNC=uncertain due to lack of data

d. Drinking Water Exposure Assessments

The most recent drinking water assessment was a refined Tier II assessment completed in 200518. 

Estimated drinking water exposure concentrations (EDWCs) were based on residues of parent 

PCNB plus PCA (identified as residues of concern by a Health Effects Division Metabolism 

Assessment Review Committee (MARC) on May 27, 2003), and were developed for the five major 

crops (i.e., turf, peanuts, cabbage, potatoes and cotton) evaluated in the environmental fate and 

ecological risk assessment written in support of the RED. Based on that assessment, the peak

surface water numbers (acute=183 μg/L; chronic=12.2 μg/L) for PCNB use on peanuts were 

selected (Table 3). Although EDWCs were higher initially for turf (acute=268 μg/L and

chronic=28.7 μg/L), once the turf concentrations were adjusted using the golf course adjustment 

factor (GCAF), they were lower than the estimates for peanuts. Groundwater-derived acute and 

chronic drinking water estimates were based on use rates for bulbs and turf, respectively (Table 3).

Table 1. Maximum Tier 1 Estimated Drinking Water Concentrations of parent PCNB in groundwater 

and surface water based on PCNB use on peanuts at 10 lbs a.i./A by ground spray application.

Drinking Water Source 

(Model Used)

Use/Rate Modeled (lb 

a.i./A)

Maximum Estimated Drinking Water 

Concentration (EDWC; ppb)

Groundwater

(SCI-GROW)

213.4 lbs/A x 1 application

to bulbs;

32.67 lbs/A x 2 

applications to turf

Acute and Chronic

30.619 (bulbs);

9.38 (turf)

Surface Water 

(PRZM/EXAMS)

Ground spray/1

application for total of 10 

lbs a.i./A

Acute 183 (peanuts)

Aerial spray/0.013 x 3 

application for total of 

0.039

Chronic 12.2 (peanuts)

 

18 USEPA. 2005. Revised/Refined Tier II Aquatic Exposure Values for the Drinking Water and Ecological Assessments of PCNB for 

Use During Phase 6 – Risk Mitigation. DP Barcode D318569.

19 Based on revised drinking water assessment; DP Barcode D291286 dated 12/22/2003.
Page 9 of 76

e. Clean Water Act Programs 

Although PCNB is not specifically identified as a cause of impairment for any water bodies listed 

as impaired under section 303(d) of the Clean Water Act20, organochlorine pesticides, and dioxins 

are all identified as such. Total Maximum Daily Loads (TMDL) have been developed for 

hexachlorobenzene

21, a contaminant of PCNB. Aquatic life benchmarks22 have been established 

for PCNB as well as for its PCA, PCB, and PCP degradates; however, any data submitted or 

otherwise located as part of the Registration Review process that indicate greater sensitivity than 

data currently available may be used to revise aquatic life benchmarks if applicable. 

5. Environmental Fate and Transport

PCNB is a persistent, moderately volatile chemical, and volatilization is expected to represent a 

relevant dissipation route for PCNB; however, the overall persistence of PCNB and its degradates 

in the air is unknown. PCNB and its major degradate PCA are classified, under the FAO mobility 

classification system, as slightly mobile to hardly mobile in soil (with KOCs ranging from 1,588 to 

17,508, and 3,337 to 10,580 respectively), whereas the major degradate PCTA is classified as 

hardly mobile (with KOCs ranging from 18,610 to 45,662). Nevertheless when applied to sandy

(course-textured) soils low in organic matter, the possibility exists for PCNB and/or its degradates 

to leach to groundwater. PCNB may also move to surface water via runoff particularly while sorbed 

to eroded sediment, via spray drift (particularly for foliar applications such as to turf, wherein the 

material is not soil-incorporated), and/or via secondary drift, i.e., drift of volatilized or soil-bound 

residues (dust) following application and leading to deposition onto nearby or more distant 

ecosystems. 

PCNB is stable to hydrolysis and effectively stable to photodegradation on soil (half-life of 80 

days). Although laboratory data suggest an important route of degradation for PCNB is aqueous 

photolysis (half-life of 1.1 to 2.5 days), the ideal circumstances that allow this mechanism to 

proceed (i.e., clear, shallow water) are expected to be often limited under natural conditions by 

turbidity, shading, and the attenuation of light with increasing water depth. Although aqueous 

photolysis represents a relatively rapid degradation pathway for parent PCNB, the products of 

photolytic degradation of PCNB have not been identified. In addition, although the biodegradate 

PCA formed at the highest relative percentage (up to 86.6% of applied radioactivity) of any PCNB 

degradate that has been identified in the available fate studies, there is currently no data on the rate 

of photolytic degradation of PCA in soil or water, and no information about the identities of any 

further degradates that may be formed from PCA by these processes. Photolytic degradation 

studies on PCA are therefore included as data gaps in this problem formulation.

Based on limited data PCNB is understood to biodegrade slowly in aerobic soils, with half-lives of 

77 and 189 days in submitted studies on sandy loams (MRIDs 42911902, 41384501, 41713202, 

and 42112801). Note that due to deficiencies and ambiguities in submitted volatility data, 

calculation of these half-lives involved conservatively adding volatilized residues to non-

 

20 Specific state causes of impairment that make up the national pesticides cause of impairment group are listed at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885.

21 Specific state pollutants that make up the National Pesticides Pollutant Group and have TMDLs are listed at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_group_name=PES

TICIDES.

22 Aquatic Life Benchmarks are available at (http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm.
Page 10 of 76

volatilized residues. However data from the published literature tend to confirm that PCNB 

degrades slowly in aerobic soil environments, with half-lives of 4.7-9.7 months reported by Wang 

and Broadbent (197223), and half-lives of 213, 425, 535 and 699 days reported by Beck and Hansen 

(197424). While data in submitted anaerobic soil metabolism studies included insufficient sampling 

intervals to enable valid calculation of degradation half-lives, substantial conversion of PCNB to 

degradates (particularly PCA and PCTA) under anaerobic conditions was found, and the data 

suggest that under such conditions these might be more persistent than the parent compound. 

Schauerte et al. (198225) found quantitative conversion of PCNB to PCA and PCTA in the sediment 

phase of an experimental pond study, although Susarla et al. (199626) found that in anaerobic 

sediment, PCNB degraded to multiple less-chlorinated anilines following an initial conversion to 

PCA. In the Schauerte et al.27 study, the majority of PCNB residues remaining in the sediment at 

up to 145 weeks post-treatment were found in the 0- to 10-cm depth layer, and decreased over time. 

In general, information concerning the rate and products of biodegradation of PCNB under both 

aerobic and anaerobic conditions is limited and incomplete. Like other chlorinated benzenes 

characterized by moderate to high volatility, PCNB can move to areas distant from use sites via 

long-range atmospheric transport. Once in the atmosphere, PCNB is not expected to degrade by 

photooxidation. 

In submitted terrestrial field dissipation studies, PCNB dissipated more rapidly in the plots in which 

the pesticide was not incorporated into soil, with a half-life range of 39-57 days (MRIDs 430615-

01; 438874-03; 412105-01, 420944-03 and 420944-04) versus a half-life range of 128-324 days 

for plots with incorporated PCNB (MRIDs 438874-01; 438874-02; 417214-01; 412164-01 and 

424859-01; 412164-02 and 424859-02). Major degradates in those studies included PCA, PCTA 

and PCB. The manufacturing contaminant HCB was detected in all except one of the field studies, 

at maximum concentrations ranging from 0.03 to 0.076 ppm. In a study of field soils (cropped with 

potatoes) in Denmark to which PCNB had been applied over the previous 5 to 11 years, Beck and 

Hansen (1974) determined field half-lives ranging from 117 to 1059 days, with a mean of 434 days 

(for 22 values). Degradates observed in the Danish field soils were PCA, PCTA and PCB.

Volatilization should be a more significant route of dissipation of the parent and the degradate PCA 

when PCNB is not incorporated, such as the foliar use on turf. In a field volatility study (MRID 

437511-01), PCNB (as Terraclor®75% WP) applied as a band application, at 10.2 lbs a.i./A, 

volatilized from an unvegetated silt loam soil in Mississippi; approximately 65% of the total 

volatiles trapped were collected during the first two days of the study. Volatilized PCNB was at a 

maximum on Day 0 and declined throughout the rest of the 13-day study. The degradate PCA was 

also detected as a volatile with peak volatility on Day 0. Weather may have confounded the study 

result though as sampling could not be conducted due to rain. The available data suggest that 

depending on use conditions, PCNB and some of its degradates may volatilize and contribute to 

atmospheric loading of the chemical(s). The extent to which this occurs cannot be quantified at 

this time; however, this loading would likely serve as a means through which PCNB could undergo 

long-range atmospheric transport. The magnitude of transport via secondary drift depends on 

PCNB’s ability to be mobilized into air and its eventual removal through wet and dry deposition of 

gases/particles and photochemical reactions in the atmosphere. Based on its vapor pressure (1.13 x 

 

23 Wang, C.H. and F. E. Broadbent. 1972. Kinetics of losses of PCNB and DCNA in three California soils. Soil Sci. Soc. Amer. Proc. 

36:742-745.

24 Beck, J. and K.E. Hansen. 1974. The degradation of quintozene, pentachlorobenzene, hexachlorobenzene and pentachloroaniline in

soil. Pestic. Sci. 5:41-48.

25 Schauerte, W., J.P. Lay, W. Klein and F. Korte. 1982. Long-term fate of organochlorine xenobiotics in aquatic ecosystems. 

Ecotoxicol. and Environ. Safety 6:560-569.

26 Susarla, S., S. Masunaga and Y. Yonezawa. 1996. Transformation of chloronitrobenzenes in anaerobic sediment. Chemosphere 

32:967-977

27 Ibid Schauerte et al. 1982.
Page 11 of 76

10

-4 Torr at 25oC), PCNB is expected to exist primarily in the vapor phase while in the atmosphere. 

Therefore, physicochemical properties of PCNB that describe its potential to enter the air from 

water or soil (e.g., Henry’s Law constant and vapor pressure), pesticide use data, modeled estimated 

concentrations in water and air, and available air monitoring data from the Central Valley and the 

Sierra Nevada Mountains are important for evaluating the potential for atmospheric transport of 

PCNB to locations where it could impact the species listed above.

PCNB has the potential to bioaccumulate in non-target organisms. Based on the results of a 

guideline study (MRID 405802-02) PCNB has the potential to bioaccumulate in the aquatic 

environment with bioconcentration factors (BCF) in fish of 1800X. Residues in bluegill sunfish 

(Lepomis macrohirus) exposed to [14C]PCNB at 1.0 ppb were bioaccumulated to a greater extent 

in the viscera, with bioconcentration factors (BCF) of 1800X in each of two studies, versus in edible 

tissue, with BCF’s of 370X and 400X; in whole fish tissue, measured BCF values were 960X and 

1100X. As reported in the literature, PCNB was bioaccumulated in rainbow trout (Oncorhynchus 

mykiss) exposed to PCNB at 0.69 ppm, with BCF’s of 114-261X28. A BCF value of 238X29 was 

reported for PCNB in topmouth gudgeon (Pseudorasbora parva). Reported BCF values for guppies 

(Poecilia reticulate) exposed to PCNB range from 363 to 1030X30. Although the compound can be 

metabolized and undergo moderately rapid depuration when the fish are no longer exposed to the 

compound, there is uncertainty regarding the extent to which the compound is readily 

metabolized/depurated in other aquatic taxa. Higher BCF values have been reported for aquatic 

plants with BCFs of 3100X31 and 4508X32.

Table 2. Chemical Properties and Environmental Fate Parameters of PCNB and Degradates (Where 

Data are Available)

Parameter Value Description/Comments Source/MRID

Selected Physical/Chemical Parameters

PC Code 056502 -- --

Molecular Mass 295.3 g/mol -- --

Molecular Formula C6Cl5NO2 -- --

Vapor pressure

(25

oC) 1.13 x 10-4 mm Hg Moderately volatile Product Chemistry

Aqueous solubility 

(25

oC) 0.44 mg/L Product Chemistry

Henry’s Law 

Constant 9.980E-005 atm-m3

/mole @ 25oC --

Estimated from water 

solubility and vapor 

pressure

 

28 Niimi, A.J., H.B. Lee and G.P. Kissoon. 1989. Octanol/water partition coefficients and bioconcentration factors of chloronitrobenzenes 

in rainbow trout (salmo gairdneri). Environ. Toxicol. Chem. 8:817-823.

29 Kanazawa, 1981. Measurement of the bioconcentration factors of pesticides by freshwater fish and their correlation with 

physicochemical properties or acute toxicities. J. Pestic. Sci. 12:417-424.

30 DeWolf, W., J.H.M. Debrujin, W. Selnen and J.L.M. Hermens. 1992. Influence of biotransformation on the relationship between 

bioconcentration factors and octanol-water partition coefficients. Environ. Sci. Technol. 26:1197-1201.

31 Korte, F., D. Freitag, H. Geyer, W. Klein, A. G. Kraus and E. Lahaniatis. 1978. Ecotoxicologic profile analysis: A concept for 

establishing ecotoxicologic priority lists for chemicals. Chemosphere 1:79-102.

32 Wang, X. , S. Harada, M. Watanabe, H. Koshikawa and H. J. Geyer. 1996. Modeling the bioconcentration of hydrophobic organic 

chemicals in aquatic organisms. Chemosphere 32:1783-93.
Page 12 of 76

Parameter Value Description/Comments Source/MRID

Log octanol-towater partition 

coefficient

(Log Kow)

4.64 @ 25oC -- Geyer et al. 198433

Air-water partition 

coefficient (log 

KAW) 

-2.743 --

Estimated using 

EPISuite

Log octanol-air 

partition coefficient 

(log KOA) 

7.38 --

Estimated using 

EPISuite

UV/visible light 

absorption 301 mm -- Khan et al., 201134

Hydrolysis half-life stable -- 408653-01, 409726-01

Aqueous photolysis 

half-life (at pH 5; in 

days)

t1/2 = 2.5 days

t1/2 = 1.12 days

Chlorinated 

hydroxybenzenes and/or 

chloronitrophenols 

identified along with 

unidentified degradates.

426062-01, 426062-02

423362-01

Soil photolysis 

half-life (days) stable -- 410048-01, 417132-01

Aerobic soil 

metabolism halflife (days)

t1/2 = 77, 189 days (parent only);

t1/2 = 983, 1052 days (total 

residues3)

(data on two sandy loam soils)

PCA (0.90 ppm)

PCTA (0.81 ppm)

PCB (0.27 ppm)

PCTASO (0.37 ppm)

PCTASO2 (0.61ppm)

429119-02, 413845-01, 

417132-02, 421128-01

Anaerobic soil 

metabolism halflife insufficient sampling intervals to 

calculate half-life

PCA (87% in soil; 27% 

in water)

PCTA (3.2% in soil)

PCP (2% in soil)

412036-02, 420944-01, 

413843-01, 416860-01, 

417132-02, 421128-02

Aerobic aquatic 

metabolism halflife (20C)

No data -- NA

Anaerobic aquatic 

metabolism halflife (20-26C)

No data -- NA

Mobility

Solid-water 

distribution 

coefficient (Kd) in 

L/kg-soil

7.3, 15.5, 19.1, 210 -- 416482-01

 

33 Geyer, H., G. Politzki, and D. Freitag. 1984. Prediction of Ecotoxicological Behaviour of Chemicals: Relationship Between NOctanol/Water Partition Coefficient and Bioaccumulation of Organic Chemicals by Alga Chlorella. Chemosphere 13(2):269-284

34 Khan, F., D. Prakash, and R.K.Jain. 2011. Development of an HPLC method for determination of pentachloronitrobenzene, 

hexachlorobenzene and their possible metabolites. BMC Chemical Biology 11:2 doi:10.1186/1472-6769-11-2
Page 13 of 76

Parameter Value Description/Comments Source/MRID

Organic-carbon 

normalized 

distribution 

coefficient (Koc)

PCNB

1588 L/kg (silt loam);

2912 L/kg (sand);

3870 L/kg (sandy loam);

17508 L/kg (clay)

-- 416482-01

PCTA (degradate)

18610 L/kg (sand)

19395 L/kg (sandy loam)

45662 L/kg (silt loam)

37267 L/kg (silty clay loam)

-- 435005-01

PCA (degradate)

3337 L/kg (sand)

7116 L/kg (sandy loam)

3581 L/kg (silt loam)

10580 L/kg (silty clay loam)

-- 435005-02

Terrestrial Field 

Dissipation

Dissipation Half-life1,2 = 

272 days, bareground, CA

459, bareground, GA

57, bareground, GA

324, potatoes, MN

39, turf, CA

128, broccoli, CA

193, MN, potatoes

PCA (0.02 – 9.24 ppm) 

PCTA (0.008 – 0.73 

ppm) 

PCB (0.02 - 0.24 ppm) 

PCTASO (0.07 ppm) 

PCTASO2 (0.6 ppm) 

417214-01

438874-01

438874-02

438874-03

430615-01

412105-01 &

420944-03 &

420944-04

412164-01 &

424859-01

412164-02

Volatility from Soil 

(Laboratory)

80% volatilized by 7 days, sandy 

loam Maximum volatilization 

within 24 hours of 

treatment.

411780-01

425074-01

Volatility from Soil 

(Field)

PCNB: 21.45 to 67.49 ng/liter 

(during four 2-hr samplings on 

day 0; silt loam)

PCA: 3.32 to 9.61 ng/liter (during 

four 2-hr samplings on day 0; silt 

loam)

Total of 65% of volatiles 

(PCNB & PCA) 

collected by day 1 postapplication., with max. 

of each compound 

volatilized on day 0. 

Since >5 inches of rain 

fell in the study area 

(precluding air sampling 

on days 4 and 9) from 

days 3 to 9, the observed 

volatilization cannot be 

considered to be 

representative of that 

which might occur over 

time under more typical 

field conditions or in 

more arid regions.

437511-01

Fish Bioconcentration
Page 14 of 76

Parameter Value Description/Comments Source/MRID

Fish 

bioconcentration 

factors (steadystate)

370-400 L/kg wet wt (edible 

tissue)

1800 L/kg wet wt (nonedible 

tissue)

960-1100 L/kg wet wt (whole fish 

tissue)

N-acetyl Spentachlorophenyl 

cystine (the cystinyl 

conjugate of PCNB): 

0.8-1.2 ppb (edible); 25-

31 ppb (nonedible) 

PCTA: 161-232 ppb 

(edible); 696-1095 ppb 

(nonedible) 

405802-02, 412000-01

NA=not applicable.

1 Half-lives were calculated using the single-first order equation and nonlinear regression, unless otherwise specified.

2The value may reflect both dissipation and degradation processes.

3Total residues for the calculation include PCNB, PCA, PCTA, PCTASO, PCTASO2, PCB, PCP, and HCB

Monitoring data

PCNB was detected in surface water at concentrations ranging up to 6.4 μg/L in a study on a limited 

number of U.S. golf courses, according to a report (MRID 463270-01) submitted to the agency in 

support of reregistration35. The possible presence of PCNB degradates was not addressed in the 

study report. However the major degradate PCA has been monitored in the Mississippi River and 

some of its major tributaries (Illinois, Missouri, Ohio, Arkansas, White, and Yazoo Rivers), and 

detected at concentrations ranging from 18 to 55 μg/L36. 

In addition to the above, according to data downloaded from the Water Quality Portal 

(http://waterqualitydata.us/portal/) on 01/07/2016, PCNB was also detected (presumably in surface 

water) at 0.59, 0.8 and 1.33 μg/L in 1998, 2001, and 1997, respectively, by “Dade Environmental 

Resource Management” in Florida. Downloaded data show that PCNB was also detected at 0.86 

μg/L by the Shoalwater Bay Tribe in 2008 in Washington State, and by the Maine Department of 

Environmental Protection in 2009, at up to 2.48 and 0.207 ng/g dry weight in “lipid” and “tissue”

samples respectively, of unspecified nature or origin.

In a U.S. Geological Survey (1992-1995) monitoring study of semi-volatile organic compounds in 

streambed sediment at 536 sites in 20 U.S. major river basins, PCNB was detected at 0.2% of the 

sites and at a maximum concentration of 180 μg/kg. Based on information in the NAWQA 

database, PCNB was detected in bed sediment at 605 sites in 45 states during 1992-2001 with three 

exceptions: it was detected at three sampling sites, i.e., Boulder Co., CO at 9 μg/kg, Adams Co., 

CO at 10 μg/kg, and Hillsborough Co., FL at 180 μg/kg). In California, the state with the highest 

usage of PCNB when evaluated for the RED37, the compound was not detected in the bed sediments 

at any of the NAWQA sampling sites at any sampling date (National Center for Food and 

Agricultural Policy

38 [NCFAP] Pesticide Use Database, 2000).

PCNB is not one of the analytes monitored in the USGS NAWQA Groundwater Monitoring 

program. Based on information contained in the USEPA’s Pesticides in Ground Water Database, 

A Compilation of Monitoring Studies: 1971-1991, National Summary, PCNB is not found in 

groundwater at significant levels or frequencies (USEPA, 1992a). In sampling of 1708 wells, only 

three detections of PCNB occurred, at a range of 0.008–0.275 μg/L. Sampled wells which did not 

 

35 USEPA. 2005. Memo from E. Behl and C. Sutton to J. Bloom; DP Barcode D308564 dated 7/19/2005.

36 Rostad CE, W.F. Pereira, and T.J. Leiker. 1993. Distribution and transport of selected anthropogenic organic compounds on 

Mississippi River suspended sediment (USA), May/June 1988. J. Contam. Hydrol. 16:175-199.

37 Ibid USEPA 2005.

38 National Center for Food and Agricultural Policy - NCFAP. Pesticide Use Database at http://www.ncfap.org (2000).
Page 15 of 76

contain measurable levels of PCNB included 459 wells in California. However, there is no related 

information available with regard to whether the monitoring sites corresponded with PCNB use 

sites or times of usage. In another groundwater monitoring study of 18 wells in three counties in 

California (July 1994–1995), PCNB was not detected (California EPA, 1995).

Based on information presented in the National Institute of Health/National Library of Medicine’s 

Hazardous Substances Data Bank39, PCA has been detected at a range of 0.1-3.75 mg/kg in soil 

samples from a field previously treated with PCNB40. In a study of soil from a field in which PCNB 

was used extensively, PCA was detected at 10.1 mg/kg41.

In a study of air samples collected in 1994 over areas of non-farmed land near Larimore, ND, PCNB 

was detected in 1 of 7 samples, at a concentration of 0.0017 ng/m3(Hawthorne et al., 199642). In 

air monitoring studies done in Canada, PCNB was detected over Saskatchewan despite no evidence 

of the application of PCNB in that area. PCNB was detected in 10 of 11 samples (at 0.01-1.60 

ng/m3) collected during a 3-month period in the summer of 1994 over Regina, Canada, and in 2 of 

5 samples collected during that time over Waskesiu, Canada; the compound was not detected in 

any of 7 samples collected over Yellowknife, Canada (Thompson et al., 199743). In an air 

monitoring study44 of pesticides in Lompoc, California, PCNB was detected in ambient air at a 

maximum acute (24-hr) concentration of 48 ng/m3, a maximum subchronic concentration of 18 

ng/m3, and a maximum chronic concentration of 8.5 ng/m3.

The detection of PCNB in the atmosphere over areas in which the pesticide was not used is evidence 

of the possibility for long-range transport of the compound. It is noted that PCNB is a listed 

Hazardous Air Pollutant (HAP) for which standards must be set under the Clean Air Act (amended 

1990). PCNB is not listed on the U.S. EPA’s list of Persistent Organic Pollutants (POPs) as found 

at http://www.epa.gov/international-cooperation/persistent-organic-pollutants-global-issueglobal-response#table; however, several contaminants of PCNB (e.g., HCB and dioxins/furans) are 

listed.

Monitoring studies of pesticide residues in honey bee colonies45 46 have demonstrated detectable 

quantities of PCNB in various hive matrices (e.g., wax, pollen). Residues in comb wax were 

detected at 2.5 ppb (limit of detection LOD=1 ppb) and in pollen at 4.7 ppb (LOD not specified).

A more recent review of monitoring data will be conducted at the completion of the PRA.

 

39 NIH. National Institute of Health, U.S. National Library of Medicine. Toxicology Data Network (TOXNET) Hazardous Substances 

Data Bank (HSDB). http://toxnet.nlm.nih.gov

40 Dejonckheere, W et al. 1981. Meded Fac Landbouwwet, Rijksuniv Gent 40: 1187-97

41 Ohsawa, K et al. 1984 Residue Analysis of Pentachloronitrobenzene and its Related Compounds in Soils by Mass Fragmentography.

J Pestic Sci 9 (2): 339-344.

42 Hawthorne, S.B., D.J. Miller, P.K.K. Louie, R.D. Butler, and G.G. Mayer. J. Environ. Qual. 25:594-600 (1996).

43 Thompson, T.S., R.G. Treble, D.T. Waite, and A.J. Cessna. Bull. Environ. Contam. Toxicol. 58: 939-944 (1997).

44 CDPR. 2003. California Department of Pesticide Regulation (CDPR). Lompoc Air Monitoring Project. 

http://www.cdpr.ca.gov/docs/specproj/lompoc/lompoc.htm

45 Mullin, CA, et al. “High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health.” 

PLoS ONE 5.3 (2010): e9754. Web. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0009754. 

doi:10.1371/journal.pone.0009754

46 Pettis, J.S., E. M. Lichtenberg, M. Andree, J. Stitzinger, R. Rose, and D. vanEngelsdorp. 2013. Crop Pollination Exposes Honey Bees 

to Pesticides which Alters their Susceptibility to the Gut Pathogen Nosema ceranae. PLoS One 8(7): e70182. 

Doi:10.1371/journal.pone.0070182. 
Page 16 of 76

a. Degradation/Transformation Products

The RED47 identifies a total of 80 degradates for PCNB. Major degradates of PCNB in the 

environment are depicted in Table 5a and include: pentachloroaniline (PCA),

pentachlorothioanisole (PCTA), and pentachlorobenzene (PCB; which is also present as an 

impurity); minor degradates are pentachlorothioanisole sulfoxide (PCTASO), and 

pentachlorothioanisole sulfone (PCTASO2). Information on maximum percentages formed of each 

degradate of concern in the available fate studies is presented in Table 5b. Pentachlorophenol 

(PCP) has been detected in several registrant-submitted studies; however, there is uncertainty 

regarding the conditions and quantities under which it occurs. Large Henry’s Law constants for 

the degradates PCA, PCTA, PCB and PCP (on the order of 10-7to 10-4atm-m

3

-mol) indicate 

that volatilization may also be an important environmental fate process for these compounds. 

Table 3a. Structures of PCNB and Its Environmental Transformation Products

Code Name/ Synonym/

Chemical Name/ Formula/MW/ SMILES Chemical Structure Occurrence

PCNB, Quintozene

IUPAC: Pentachloronitrobenzene

CAS: 1,2,3,4,5-Pentachloro-6-nitrobenzene

CAS Number: 82-68-8

Formula: C6Cl5NO2

MW: 195.33 g/mole

SMILES: O=N(=O)c(c(c(c(c1Cl)Cl)Cl)Cl)c1Cl

All matrices

PCA, Pentachloroaniline

IUPAC: 2,3,4,5,6-Pentachloroaniline

CAS Number: Not available

Formula: C6H2Cl5N

MW: 265.35 g/mole

SMILES: c1(c(c(c(c(c1Cl)Cl)Cl)Cl)Cl)N

Aerobic & anaerobic 

soil, Terrestrial field 

dissipation (major)

PCTA, Pentachlorothioanisole

IUPAC: 1,2,3,4,5-Pentachloro-6-

methylsulfanyl-benzene

CAS Number: Not available

Formula: C7H3Cl5S

MW: 296.43 g/mole

SMILES: CSc1c(c(c(c(c1Cl)Cl)Cl)Cl)Cl

Aerobic & anaerobic 

soil, Terrestrial field 

dissipation, 

Bioaccumulation in 

fish

PCB, Pentachlorobenzene

IUPAC: 1,2,3,4,5-Pentachlorobenzene

CAS Number: Not available

Formula: C6HCl5

MW: 250.34 g/mole

SMILES: c1c(c(c(c(c1Cl)Cl)Cl)Cl)Cl

Aerobic soil, 

Terrestrial field 

dissipation

Trihydroxydichloronitrobenzene

IUPAC Name: 4,5-Dichloro-6-nitro-benzene1,2,3-triol

CAS number: Not available

MW: 239.99 g/mole

Formula: C6H3Cl2NO5

SMILES:

c1(c(c(c(c(c1Cl)Cl)O)O)O)[N+](=O)[O-]

Aqueous photolysis 

(Tentatively 

identified: MRID 

42336201)

 

47 Ibid USEPA. 2006. 
Page 17 of 76

Code Name/ Synonym/

Chemical Name/ Formula/MW/ SMILES Chemical Structure Occurrence

HCB, Hexachlorobenzene

IUPAC: 1,2,3,4,5,6-Hexachlorobenzene

CAS Number: Not available

Formula: C6Cl6

MW: 284.78 g/mole

SMILES: c1(c(c(c(c(c1Cl)Cl)Cl)Cl)Cl)Cl

Terrestrial field 

dissipation

PCP, Pentachlorophenol

IUPAC Name: 2,3,4,5,6-Pentachlorophenol

CAS number: Not available

MW: 266.34 g/mole

Formula: C6HCl5O

SMILES: c1(c(c(c(c(c1Cl)Cl)Cl)Cl)Cl)O

Anaerobic soil, 

Terrestrial field 

dissipation

PCTASO, Pentachlorothioanisole sulfoxide, 

PCPM sulfoxide, Pentachlorophenylmethyl

sulfoxide, Metabolite 6

IUPAC Name: 1,2,3,4,5-Pentachloro-6-

methylsulfinyl-benzene

CAS number: Not available

MW: 312.43 g/mole

Formula: C7H3Cl5OS

SMILES: CS(=O)c1c(c(c(c(c1Cl)Cl)Cl)Cl)Cl

Aerobic soil, 

Terrestrial field 

dissipation, 

Bioaccumulation in 

fish

PCTASO2, Pentachlorothioanisole sulfone, 

PCPM sulfone, Pentachlorophenylmethyl 

sulfone

IUPAC Name: 1,2,3,4,5-Pentachloro-6-

methylsulfonyl-benzene

CAS number: Not available

MW: 328.43 g/mole

Formula: C7H3Cl5O2S

SMILES:

CS(=O)(=O)c1c(c(c(c(c1Cl)Cl)Cl)Cl)Cl

Aerobic soil

TCTASO2, Tetrachlorothioanisole sulfone 

IUPAC Name: 1,2,3,4-Tetrachloro-5-

methylsulfonyl-benzene

CAS number: Not available

MW: 293.98 g/mole

Formula: C7H4Cl4O2S

SMILES: CS(=O)(=O)c1cc(c(c(c1Cl)Cl)Cl)Cl

Terrestrial field 

dissipation

N-Acetyl S-Pentachlorophenyl cystine, 

Cystinyl conjugate of PCNB

IUPAC Name: 2-Acetamido-3-(2,3,4,5,6-

pentachlorophenyl)sulfanyl-propanoic acid

CAS number: Not available

MW: 411.52 g/mole

Formula: C11H8Cl5NO3S

SMILES:

CC(=O)NC(CSc1c(c(c(c(c1Cl)Cl)Cl)Cl)Cl)C(=

O)O

Bioaccumulation of 

Fish (Major)
Page 18 of 76

Code Name/ Synonym/

Chemical Name/ Formula/MW/ SMILES Chemical Structure Occurrence

PCHA, Pentachlorohydroxyaniline

IUPAC Name: N-(2,3,4,5,6-

pentachlorophenyl)hydroxylamine

CAS number: Not available

MW: 281.35 g/mole

Formula: C6H2Cl5NO

SMILES: c1(c(c(c(c(c1Cl)Cl)Cl)Cl)Cl)NO

Aerobic soil 

metabolism

(MRID 42911902; 

Reference compound)

TCA, Tetrachloroaniline

IUPAC Name: 2,3,5,6-Tetrachloroaniline

CAS number: Not available

MW: 230.9 g/mole

Formula: C6H3Cl4N

SMILES: c1c(c(c(c(c1Cl)Cl)N)Cl)Cl

Aerobic soil 

metabolism

(MRID 42911902; 

Reference compound)

TCNB, Tetrachloronitrobenzene

IUPAC Name: 1,2,3,5-Tetrachloro-4-nitrobenzene

CAS number: Not available

MW: 260.89 g/mole

Formula: C6HCl4NO2

SMILES: c1c(c(c(c(c1Cl)Cl)Cl)[N+](=O)[O-

])Cl

Aerobic soil 

metabolism

(MRID 42911902; 

Reference compound)

2,3,4,5-TCNB, 2,3,4,5-

Tetrachloronitrobenzene

IUPAC Name: 1,2,3,4-Tetrachloro-5-nitrobenzene

CAS number: Not available

MW: 260.89 g/mole

Formula: C6HCl4NO2

SMILES:

c1c(c(c(c(c1Cl)Cl)Cl)Cl)[N+](=O)[O-]

Hydrolysis (MRID 

40865301, 40972601); 

Soil Photolysis 

(MRID 41004801) 

(Reference 

compound)

2,3,5,6-TCNB, 2,3,5,6-

Tetrachloronitrobenzene

IUPAC Name: 1,2,4,5-Tetrachloro-3-nitrobenzene

CAS number: Not available

MW: 260.89 g/mole

Formula: C6HCl4NO2

SMILES: c1c(c(c(c(c1Cl)Cl)[N+](=O)[O-

])Cl)Cl

Hydrolysis (MRID 

40865301, 40972601); 

Soil Photolysis 

(MRID 41004801) 

(Reference 

compound)

Table 5b. Maximum amount of applied radioactivity present as a specified compound in 

environmental fate studies submitted on PCNB

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

Parent Hydrolysis

102.0% (7 d) 100.0% (30 d) pH 5 40865301

100.0% (0 d) 98.2% (30 d) pH 7 40865301
Page 19 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

102.0% (14 d) 100.3% (30 d) pH 7 40865301

104.3% (7 d) 99.6% (30 d) pH 9 40865301

101% (1 d) 98.2% (30 d) pH 5 40972601

103% (1 d) 96.0% (30 d) pH 7 40972601

103% (1 d) 101% (30 d) pH 7 40972601

106% (13 d) 100% (30 d) pH 9 40972601

Aqueous 

Photolysis

100.0% (0 h) 21.0% (32 h) pH 5 42336201

99.76% (0 d) 13.39% (7 d) pH 5 42606201

42606202

Soil 

Photolysis 100.0% of Time 0 (7 d) 74.7% (30 d) Sandy loam 4100480141713201

Aerobic 

Soil

9.96 μg/g (0 d) 2.33 μg/g (365 d) Sandy loam 42911902

94.9% (0 d) 3.1% (365 d) Sandy loam

41384501

41713202

42112801

Anaerobic 

Soil

85.9% of rec (1 d) 3.8% of rec (90 d) Sandy loam (in 

soil) 41203602

42094401

4.9% of rec (90 d) 4.9% of rec (90 d) Sandy loam (in 

water)

94.9% (0 d) 0.7% (90 d) Sandy loam

41384301

41686001

41713203

42112802

Terrestrial 

Field 

Dissipation

59.539 ppm (0 d) 0.041 ppm (535 d) Georgia, 

Loamy sand 43061501

245.0 ppm (0 d) 66.0 ppm (241 d)

California, 

Loamy sand 

(Bare)

43887401

191.0 ppm (0 d) 188.0 ppm (269 d)

Georgia, 

Sandy loam 43887402

9.1 ppm (0 d) 3.3 ppm (515 d) Minnesota, 

Loam 41721401

9.9 ppm (1 d) 0.40 ppm (543 d)

California, 

Loamy sand 

(Broccoli)

41216401

42485901

6.8 ppm (28 d) 1.0 ppm (546 d)

Minnesota, 

Sandy loam

41216402

42485902

Bioaccumu

lation in 

Fish

ND ND (28 d) Edible tissues

9.5 ppb (28 d) 9.5 ppb (28 d) 43179301 Non-edible 

tissues

0.51 ppb (0 d) 0.106 ppb (28 d) Water extracts
Page 20 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

930 μg/kg (35 d) 930 μg/kg (35 d) Whole Fish

41200001

41951701

350 μg/kg (35 d) 350 μg/kg (35 d) Edible tissues

1600 μg/kg (35 d) 1600 μg/kg (35 d) Non-edible 

tissues

1.2 μg/L (14 d) 1.0 μg/L (35 d) Water extracts

0.01 ppm (35 d) 0.01 ppm (35 d)

Edible tissues 

(Organic 

extractable)

0.204 ppm (21 d) 0.022 ppm (35 d)

Non-edible 

tissues 

(Organic 

extractable)

0.0002 ppm (21, 28, 35 

d) 0.0002 ppm (35 d)

Water extracts 

(Organic 

extractable)

520 ppb (21, 28 d) 520 ppb (28 d) Whole Fish

40580202

200 ppb (21 d) 180 ppb (28 d) Edible tissues

990 ppb (28 d) 990 ppb (28 d) Non-edible 

tissues

0.67 ppb (14 d) 0.54 ppb (28 d) Water extracts

Major Degradate

PCA

Aerobic 

soil

0.91 μg/g (120, 180 d) 0.80 μg/g (365 d) Sandy loam 42911902

12.9% (122 d) 9.9% (365 d) Sandy loam

41384501

41713202

42112801

Anaerobic 

Soil

86.6% of rec (60 d) 84.1% of rec (90 d) Sandy loam (in 

soil) 41203602

42094401

28.3% of rec (90 d) 28.3% of rec (90 d) Sandy loam (in 

water)

70.3% (60 d) 66.5% (90 d) Sandy loam

41384301

41686001

41713203

42112802

Terrestrial 

Field 

Dissipation 

9.24 ppm (1 d) 0.29 ppm (535 d) Georgia, 

Loamy sand 43061501
Page 21 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

0.93 ppm (210 d) 0.83 ppm (241 d)

California, 

Loamy sand 

(Bare)

43887401

2.6 ppm (269 d) 2.6 ppm (269 d)

Georgia, 

Sandy loam 43887402

1.1 ppm (515 d) 1.1 ppm (515 d) Minnesota, 

Loam 41721401

1.1 ppm (455 d) 0.95 ppm (543 d)

California, 

Loamy sand 

(Broccoli)

41216401

42485901

1.4 ppm (546 d) 1.4 ppm (546 d)

Minnesota, 

Sandy loam

41216402

42485902

N-Acetyl SPentachlorophenyl 

cystine, Cystinyl 

conjugate of PCNB

Bioaccumu

lation in 

Fish

1.22 ppb (21 d) 0.76 ppb (28 d) Edible tissues

30.97 ppb (21 d) 24.89 ppb (28 d) Non 43179301 -edible 

tissues

0.274 ppb (21 d) 0.241 ppb (28 d) Water extracts

Unknown 4

Aqueous 

Photolysis 26.26% (4 d) 24.6% (7 d) pH 5 4260620142606202

Unknown 5

Aqueous 

Photolysis 20.46% (5 d) 18.38% (7 d) pH 5 4260620142606202

Other Degradates

PCTA Aerobic 

soil

0.81 μg/g (120 d) 0.53 μg/g (365 d) Sandy loam 42911902

1.9% (30 d) 0.7% (365 d) Sandy loam

41384501

41713202

42112801
Page 22 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

Anaerobic 

soil

9.1% of rec (0 d) ND (90 d) Sandy loam (in 

soil)

41203602

42094401

1.9% (30 d) <0.1% (90 d) Sandy loam

41384301

41686001

41713203

42112802

Terrestrial 

Field 

Dissipation

0.138 ppm (120 d) 0.027 ppm (535 d) Georgia, 

Loamy sand 43061501

0.26 ppm (210 d) 0.21 ppm (241 d)

California, 

Loamy sand 

(Bare)

43887401

0.78 ppm (269 d) 0.78 ppm (269 d)

Georgia, 

Sandy loam 43887402

0.25 ppm (125, 295 d) 0.17 ppm (515 d) Minnesota, 

Loam 41721401

0.45 ppm (28 d) 0.18 ppm (543 d)

California, 

Loamy sand 

(Broccoli)

41216401

42485901

0.15 ppm (56 d) 0.11 ppm (546 d)

Minnesota, 

Sandy loam

41216402

42485902

Bioaccumu

lation in 

Fish

232.33 ppb (28 d) 232.33 ppb (28 d) Edible tissues

43179301

1094.61 ppb (21 d) 696.41 ppb (28 d) Non-edible 

tissues

0.336 ppm (35 d) 0.336 ppm (35 d)

Edible tissues 

(Organic 

extractable)

41200001

41951701

0.985 ppm (35 d) 0.985 ppm (35 d)

Non-edible 

tissues 

(Organic 

extractable)

PCB

Aerobic 

soil 0.27 μg/g (60 d) 0.20 μg/g (365 d) Sandy loam 42911902

Terrestrial 

Field 

Dissipation

0.03 ppm (158 d) 0.006 ppm (535 d) Georgia, 

Loamy sand 43061501

0.076 ppm (241 d) 0.076 ppm (241 d)

California, 

Loamy sand 

(Bare)

43887401
Page 23 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

0.24 ppm (269 d) 0.24 ppm (269 d)

Georgia, 

Sandy loam 43887402

0.24 ppm (84 d) 0.879 ppm (543 d)

California, 

Loamy sand 

(Broccoli)

41216401

42485901

0.22 ppm (546 d) 0.22 ppm (546 d)

Minnesota, 

Sandy loam

41216402

42485902

PCP

Anaerobic 

soil

2.0% of rec (90 d) 2.0% of rec (90 d) Sandy loam (in 

soil) 41203602

42094401

7.5% of rec (60 d) 6.6% of rec (90 d) Sandy loam (in 

water)

Terrestrial 

Field 

Dissipation

0.161 ppm (14 d) <0.005 ppm (535 d) Georgia, 

Loamy sand 43061501

PCTASO 

(Metabolite 6)

Aerobic 

soil 0.37 μg/g (365 d) 0.37 μg/g (365 d) Sandy loam 42911902

Terrestrial 

Field 

Dissipation

0.069 ppm (270 d) 0.055 ppm (535 d) Georgia, 

Loamy sand 43061501

Bioaccumu

lation in 

Fish

0.85 ppb (21 d) ND ppb (28 d) Edible tissues

43179301 8.47 ppb (21 d) ND ppb (28 d) Non-edible 

tissues

0.013 ppb (21 d) ND ppb (28 d) Water extracts

PCTASO2

Aerobic 

soil 0.61 μg/g (365 d) 0.61 μg/g (365 d) Sandy loam 42911902

HCB

Terrestrial 

Field 

Dissipation

0.047 ppm (1 d) <0.005 ppm (535 d) Georgia, 

Loamy sand 43061501

0.055 ppm (0 d) <0.025 ppm (241 d)

California, 

Loamy sand 

(Bare)

43887401

0.075 ppm (269 d) 0.075 ppm (269 d)

Georgia, 

Sandy loam 43887402
Page 24 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

0.032 ppm (455 d) 0.015 ppm (543 d)

California, 

Loamy sand 

(Broccoli)

41216401

42485901

0.029 ppm (546 d) 0.029 ppm (546 d)

Minnesota, 

Sandy loam

41216402

42485902

TCTASO2

Terrestrial 

Field 

Dissipation

0.013 ppm (460 d) 0.011 ppm (535 d) Georgia, 

Loamy sand 43061501

Trihydroxydichloro

nitrobenzene

Aqueous 

Photolysis Not provided Not provided (32 h)

pH 5 

(Tentatively 

identified)

42336201

CO2

O=C=O

Aerobic 

Soil

0.67% (365 d) 0.67% (365 d) Sandy loam 42911902

0.4% (365 d) 0.4% (365 d) Sandy loam

41384501

41713202

42112801

Anaerobic 

Soil 0.65 μg/g (30 d) 0.51 μg/g (365 d) Sandy loam 4120360242094401

Polar compunds1 Aerobic 

Soil 6.1% (122 d) 5.1% (365 d) Sandy loam

41384501

41713202

42112801

Unknown Anaerobic 

Soil 7.0% (60 d) 6.2% (90 d) Sandy loam

41384301

41686001

41713203

42112802

Unextracted 

Residues

Aerobic 

Soil

17.06% (365 d) 17.06% (365 d) Sandy loam 42911902

7.4% (273 d) 6.1% (365 d) Sandy loam

41384501

41713202

42112801

Anaerobic 

Soil 11.7% of rec (60 d) 9.48% of rec (90 d) Sandy loam 4120360242094401
Page 25 of 76

Compound Study 

Type

Max %AR (Sampling 

Interval)

Final %AR (Sampling 

Interval) Comment MRID

10.4% (60 d) 9.7% (90 d) Sandy loam

41384301

41686001

41713203

42112802

b. Contaminants

PCNB contains the manufacturing contaminant hexachlorobenzene (HCB). Based on studies 

reported in the open literature, PCNB also contains the manufacturing contaminants consisting of

PCB and various congeners of tetrachlorodibenzo-p-dioxin (TCDD) and tetrachlorodibenzofuran 

(TCDF)48 49 50. The presence and concentrations of most or all of these contaminants in the PCNB 

manufacturing-use product were not reported, even though registrants are obligated to identify such 

contaminants on a product’s “Confidential Statement of Formula” or CSF. Consequently, in 2010, 

EPA issued a stop sale, use or removal order (SSURO51) for the PCNB product. In response to that 

order, the registrant agreed to monitor TCDD and TCDF residues in their product and maintain 

them below a specified level, and the order was lifted.

There are 210 different congeners of dioxins/furans (75 PCDDs and 135 PCDFs); however, only 

17 congeners are considered to be of toxicological concern (listed in Table 4). For these 17 

congeners, evidence is sufficient to conclude that a common mechanism of action, involving 

binding of the chemicals to the aryl hydrocarbon receptor (AHR) as the initial step, underlies 

2,3,7,8-TCDD-like toxicity elicited by these PCDDs, PCDFs, and polychlorinated biphenyls 

(PCBs) (Van den Berg et al., 199852, 200653; Hahn, 200254). 

A great deal of research has been conducted to characterize the toxicities of PCDDs and PCDFs 

especially relative to each other, since these compounds are often present together in the 

environment. Demonstrated toxic effects of 2,3,7,8-TCDD and other similar-acting PCDD, PCDF 

and PCB congeners in fish, birds, and mammals, including adverse effects on reproduction, 

development, and endocrine functions; wasting syndrome; immunotoxicity; and mortality in both 

laboratory and field settings, were discussed in the 2008 White Paper (USEPA 2008b

55). The EPA 

(USEPA 2008b) and the World Health Organization (Van Den Berg et al. 199856 and 200657) have 

established toxicity equivalency factors (TEFs) for dioxins/furans as they relate to mammals, to 

 

48 Huang J. J. Gao, G. Yu, N. Yamazaki, S Deng, B. Wang and R. Weber. 2014. Unintentional formed PCDDs, PCDFs, and DL-PCBs 

as impurities in Chinese pentachloronitrobenzene products. Environ. Sci Pollut Res DOI 10.1007/s11356-014-3507-2. 

49 Holt E., R. Weber, G. Stevenson, and C. Gaus. 2010. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) impurities in 

pesticides: a neglected source of contemporary relevance. Environ Sci Technol 44:5409–5415

50 Holt, E., R. Weber, G. Stevenson, and C. Gaus. 2012. Formation of dioxins during exposure of pesticide formulations to sunlight. 

Chemosphere 88: 364 – 370.

51 USEPA. 2010. STOP SALE, USE OR REMOVAL ORDER AMVAC AND AMVAC Chemical Corporation. Memo from Rosemarie 

A. Kelly, Director, Waste and Chemical Enforcement Division.

52Van den Berg, M., L. Birnbaum, A.T. Bosveld et al. 1998. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans 

and wildlife. Environ. Health Perspect. 106(12):775-792.

53Van den Berg, M., L.S. Birnbaum, M. Denison et al. 2006. The 2005 World Health Organization re-evaluation of human and 

mammalian toxic equivalency factors for dioxins and dioxin-like compounds. Toxicol. Sci. 93(2):223-241.

54 Hahn, M. E. 2002. Aryl hydrocarbon receptors: diversity and evolution. Chem. Biol. Interact. 141: 131 – 160.

55 Ibid USEPA 2008b

56 Ibid van den Berg et al. 1998

57Ibid van den Berg et al. 2006
Page 26 of 76

birds and to fish (Table 4). In the TEF approach, the toxicities of individual congeners are related 

to 2,3,7,8-TCDD, which is the most toxic congener of dioxins/furans to animals (USEPA 2008a; 

Table 4). For each PCDD and PCDF, the concentration (or mass) of the chemical is multiplied by 

its TEF. The sum of the product for each PCDD and PCDF represents the toxicity equivalent (TEQ) 

concentration relative to 2,3,7,8-TCDD (Equation 1; USEPA 2008a). 

Equation 1

The TEQ approach described above will be used to assess the potential contribution of 

dibenzodioxin/dibenzofuran contaminants of PCNB to the total risk based on both estimated and 

measured residues of these contaminants in formulated products of PCNB.

Table 4. Dioxin/furan congeners that are of toxicological concern. Toxicity equivalency factors for 

mammals, birds and fish associated with each isomer are from USEPA 2008a.

Congener* Mammal TEF Bird TEF Fish TEF

2378-TCDF 0.1 1 0.05

12378-PeCDF 0.03 0.1 0.05

23478-PeCDF 0.3 1 0.5

123478-HxCDF 0.1 0.1 0.1

123678-HxCDF 0.1 0.1 0.1

234678-HxCDF 0.1 0.1 0.1

123789-HxCDF 0.1 0.1 0.1

1234678-HpCDF 0.01 0.01 0.01

1234789-HpCDF 0.01 0.01 0.01

OCDF 0.0003 0.0001 <0.0001

2378-TCDD 1 1 1

12378-PeCDD 1 1 1

123478-HxCDD 0.1 0.05 0.5

123678-HxCDD 0.1 0.01 0.01

123789-HxCDD 0.1 0.1 0.01

1234678-HpCDD 0.01 <0.001 0.001

OCDD 0.0003 0.001 <0.001

*Abbreviations are as follows: TCDD = tetrachlorodibenzodioxin; PeCDD = pentachlorodibenzodioxin; HxCDD = 

hexachlorodibenzodioxin; HpCDD = Heptachlorodibenzodioxin; OCDD = Octachlorodibenzodioxin; TCDF = 

Tetrachlorodibenzofuran; PeCDF = Pentachlorodibenzofuran; HxCDF = Hexachlorodibenzofuran; HpCDF = 

Heptachlorodibenzofuran; OCDF = octachlorodibenzofuran

6. Receptors

Tables 7 and 8 provide a summary of the most sensitive acute and chronic toxicity values for PCNB 

across aquatic and terrestrial taxonomic groups, respectively. Based on the available ecotoxicity 

information, PCNB is highly toxic to freshwater fish and invertebrates and very highly toxic to 

estuarine/marine fish and invertebrates on an acute exposure basis. PCNB is practically non-toxic 

to terrestrial invertebrates (via contact), birds, and mammals on an acute exposure basis. No 
Page 27 of 76

guideline toxicity data are available to assess the toxicity of PCNB to terrestrial or aquatic plants. 

Since no data are available specific to aquatic-phase amphibians, freshwater fish are used as 

surrogates. Since no data are available for reptiles or terrestrial-phase amphibians, birds serve as a 

surrogate for these taxa. 

Table 5. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for

PCNB.

Taxonomic 

Group

Study 

Type Surrogate Species Toxicity Value

Acute 

Toxicity 

Classification

Source

(MRID)

Freshwater Fish

Acute Bluegill sunfish

Lepomis macrochirus

96-hr LC50 =0.10 mg 

a.i./L Highly toxic 406180-0

Chronic 

Rainbow trout

(Onchorhynchus 

mykiss)

NOAEC =0.013 mg 

a.i./L

LOAEC =0.032 mg 

a.i./L

NA 416634-01

Freshwater 

invertebrates

Acute Waterflea

Daphna magna 

48- hr EC50 0.77 mg 

a.i./L Highly toxic Acc. No. 114167

Chronic Waterflea (Daphnia 

magna)

NOAEC =0.018 mg 

a.i./L

LOAEC =0.030 mg 

a.i/L

NA 413213-01

Estuarine/marine 

fish

Acute

Sheepshead minnow

(Cyprinodon 

variegatus)

96-hr LC50 =7.9 mg 

a.i./L Highly toxic 408829-03

Chronic No data 

Estuarine/marine 

shrimp Acute Mysid shrimp (Americamysis bahia)

96-hr LC50=0.012 mg 

a.i./L

Very highly 

toxic 408323-01

Estuarine/marine 

mollusk Acute

Eastern oyster shell 

deposition (Crassostrea 

virginica)

96-hr EC50=0.023 mg

a.i./L 

Very highly 

toxic 408829-02

Estuarine/marine 

invertebrate Chronic No data

Aquatic plants 

Vascular No data

Nonvascular No data

NA=not applicable

c. Effects to Terrestrial Organisms

Table 6. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

PCNB.
Page 28 of 76

Taxonomic 

Group

Acute/ 

Chronic Surrogate Species Toxicity Value 

Acute 

Toxicity 

Classification

Source

(MRID)

Birds 

(surrogate for 

terrestrialphase 

amphibians 

and reptiles)

Acute

Oral

Bobwhite quail 

(Colinus 

virginianus)

LD50 >2250 mg 

a.i./kg bw

Practically nontoxic 406180-01

Subacute 

Dietary

Bobwhite quail 

(Colinus 

virginianus)

LC50>54,000 

mg/kg diet

Practically nontoxic 406526-02

Chronic

Bobwhite quail 

(Colinus 

virginianus)

NOAEC=600

mg/kg diet

LOAEC=1200 

mg/kg diet

NA 413328-01

Mammals

Acute Laboratory rat

Rattus norvegicus

LD50 >5,050 mg/kg 

bw

Practically nontoxic 414431-01

Chronic Laboratory rat

Rattus norvegicus

NOAEL=200

mg/kg/day

LOAEL=2,000

NA 434693-03

Terrestrial 

invertebrates Acute HoneybeeApis mellifera

LC50>100 μg 

a.i./bee

Practically 

non-toxic 405061-02

Terrestrial 

Plants

N/A

Seedling 

Emergence

Monocots

No data

N/A

Seedling 

Emergence

Dicots

No data

N/A Vegetative Vigor

Monocots No data

N/A Vegetative Vigor

Dicots No data

NA=not applicable

d. Ecological Incidents

A review on September 21, 2015 of the Ecological Incident Information System (EIIS, version 

2.1.1), which is maintained by the Agency’s Office of Pesticide Programs, identified two incidents

reported for PCNB in the Ecological Incident Information System. One incident (IO10837-012)

pertains to cotton plant damage (655 acres of planted with cotton failed to germinate in South 

Carolina) following a registered use in which there was unincorporated granular application of 

PCNB in May 2000; however, no data were available to evaluate the effects of PCNB on either 

terrestrial or aquatic plants. The second incident (IO15152-001) was characterized as an accidental 

misuse in which PCNB formulated product Rival® was inadvertently mixed with thiabendazole,

captan, and tebuconazole and used to treat soybean seeds and resulted in damage (stunting) to

21,494 acres of soybeans in the Midwest in 2004. Growers were instructed to destroy soybean crops 

to which the mixture was applied.
Page 29 of 76

There are a total of sixteen incidents involving freshwater fish kills that are associated with the 

degradate PCP with as many as 424,678 fish dead; however, the incident reports are not detailed 

enough to determine the source of the PCP. It is likely that PCP at a sufficient concentration to 

result in acute mortality would have originated from the use of this chemical as a wood preservative.

Other residues of concern identified for PCNB are either not listed in the EIIS or are listed (e.g., 

HCB), but have no incidents associated with them.

Other incident reporting systems (e.g., Avian Incident Monitoring System maintained by the 

American Bird Conservancy, National Pesticide Information Center maintained by Oregon State 

University) will be reviewed in advance of the preliminary risk assessment. 

7. Exposure Pathways of Concern

The environmental fate properties and use patterns of PCNB indicate that direct spray, spray drift, 

leaching through soil (to groundwater or to surface water via subsurface lateral flow), runoff, 

volatilization, and long-range atmospheric transport represent potential transport mechanisms of 

PCNB for exposure to non-target aquatic and terrestrial organisms. Drinking water and inhalation 

exposure pathways were screened using the SIP (Screening Imbibition Program) and STIR 

(Screening Tool for Inhalation Risk) screening models. STIR indicated the inhalation pathway was

not likely significant for mammals; however, for birds and based on the ratio of the droplet 

inhalation does to the adjusted inhalation LD50, inhalation may be a significant pathway. STIR 

recommended proceeding to refinements (Appendix B). PCNB is practically non-toxic to birds

and mammals on an acute oral exposure basis and chronic exposure resulted in no-observed adverse 

effect levels of 600 mg/kg diet for birds and at 200 mg/kg bw for mammals. The SIP model 

indicated exposure through drinking water alone was not of potential concern for acute and chronic 

risk to birds or mammals (Appendix B). The SIP and STIR models are described in detail at 

http://www.epa.gov/oppefed1/models/terrestrial/index.htm.

Consistent with other chlorinated benzenes with moderate to high volatility, PCNB and other 

residues of concern can also move to areas distant from use sites via long-range atmospheric 

transport. Once in the atmosphere, PCNB is not expected to degrade by photo-oxidation and is 
Page 30 of 76

expected to persist. Other residues of concern are also volatile and the extent to which they too are 

subject to long-range transport is uncertain.

The presence of PCNB in benthic sediments is expected to serve as a likely route of exposure to 

benthic fauna and serve as a means of entry into aquatic food chains where the compound and/or 

its degradates may biomagnify as well. 

8. Analysis Plan

e. Stressors of Concern

i. Ecological Risk Assessment

For aquatic ecological risk assessment, estimated environmental concentrations will be based on 

total residues of PCNB (i.e., parent plus PCA, PCTA, PCTASO, PCTASO2, PCP). Risks from

additional stressors such as manufacturing by-products of concern including hexachlorobenzene 

(HCB), pentachlorobenzene (PCB; also a degradate), and congeners (structurally related 

chemicals) of polychlorinated dibenzodioxins/dibenzofurans (dioxins/furans) will be addressed 

qualitatively.

ii. Drinking Water 

EFED recently introduced the PRZM-GW model for determining estimated drinking water 

concentrations (EDWCs) in groundwater. For this reason, because EFED anticipates having new 

fate data to work with in assessing exposure, as well as to address any newly-approved uses that 

have not yet been assessed, an updated drinking water assessment will be completed. The human 

Health Effects Division (HED) will likely conduct a new dietary exposure and risk assessment if 

there are significant changes in the EDWCs. EDWCs will be calculated for PCNB and its residues

of concern. Historically, EDWCs have been generated for PCNB and PCA, and EFED will work 

with HED to identify the appropriate residues for EDWCs.

f. Measures of Exposure 

EFED will use standard available models (identified in Table 7) to evaluate potential exposures to 

aquatic and terrestrial organisms as described at http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticide-risk-assessment. EFED will use a total toxic residues 

(TTR) approach for assessing risk to biota from residues of PCNB and its degradates and 

contaminants of concern. Accordingly, in the absence of sufficient data to estimate formation and 

degradation rates for all separate components of concern, the Agency will follow a TTR approach 

in estimating degradation half-lives for use in aquatic residue modeling.

Since the previous exposure assessments were completed, four main changes in standard 

procedures have been made: 

1) The North American Free Trade Agreement (NAFTA) Guidance for Evaluating and 

Calculating Degradation Kinetics in Environmental Media (USEPA, 2012b58) was completed. 

Degradation kinetics may be recalculated consistent with the updated approach.

 

58 USEPA. 2012. NAFTA Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media. 

http://www2.epa.gov/sites/production/files/2015-08/documents/ftt_nafta_guidance_evaluate_calculate_degradation_kinetics.pdf
Page 31 of 76

2) The Pesticide in Water Calculator has replaced the older version of PRZM/EXAMS and will 

be used to evaluate runoff from fields treated with irrigation water. 

3) The Pesticide Root Zone Model – Groundwater (PRZM-GW) will be used for estimating 

concentrations in groundwater from fields treated with irrigation water (USEPA 201259).

4) The Bee-REX Model is a screening-level tool intended for assessing exposure of bees to 

pesticides and to calculate risk quotients for individual bees (USEPA 201560).

5) The Kow-based Aquatic Bioaccumulation Model (KABAM) will be used to estimate potential 

bioaccumulation of hydrophobic organic pesticides in freshwater aquatic food webs and 

subsequent risks to mammals and birds via consumption of contaminated aquatic prey (USEPA 

200961).

The most up-to-date procedures62 63 64 65 and models will be used in the Registration Review

exposure assessments. Nonstandard modeling procedures that may be used in the risk assessment 

are discussed below. In the absence of data to the contrary, the T-REX model will employ the 

default 35-day foliar dissipation half-life value.

Drinking Water for Ecological Organisms

Screening-level calculations using SIP indicates that drinking water exposure is not likely to pose 

a significant risk for terrestrial organisms (Appendix B). 

Table 7. List of the various models and the related taxa for which the models will be used.

Environment Taxa of 

Concern

Exposure 

Pathway

Model(s) or 

Pathway Link

Aquatic

Fish/ 

Invertebrates

/ Plants

Runoff and spray 

drift to water PWC http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticideDirect application risk-assessment

to water PFAM

Terrestrial Vertebrate Residues in/on 

dietary items T-REX (dietary item)

http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticiderisk-assessment#trex

 

59 USEPA. 2012. PRZM-GW Version 1.07 Guidance for Selecting Input Parameters for Modeling Pesticide Concentration sin 

Groundwater Using the Pesticide Root Zone Model. Version 1.0 October 15, 2012. http://www2.epa.gov/pesticide-science-andassessing-pesticide-risks/przm-gw-version-107-guidance-selecting-input

60 USEPA 2015. BeeREX Version 1.0. http://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/models-pesticide-riskassessment.

61 USEPA. 2009. KABAM (Kow (based) Aquatic Bioaccumulation Model. Version 1.0 Dated April 7, 2009. 

http://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/models-pesticide-risk-assessment#kabam 

62 USEPA. 2014. Development of Community Water System Drinking Water Intake Percent Cropped Area Adjustment Factors for use 

in Drinking Water Exposure Assessments: 2014 Update. 9/9/14. Environmental Fate and Effects Division. Office of Chemical Safety 

and Pollution Prevention. U.S. Environmental Protection Agency. Available on-line at: http://www.epa.gov/sites/production/files/2015-

07/documents/development_and_use_of_community_water_system.pdf.

63 USEPA. 2014. Guidance for Addressing Unextracted Residues in Laboratory Studies. Memorandum From to E. F. a. E. Division. 

September 12, 2014. Environmental Fate and Effects Division. Office of Pesticide Programs. Office of Chemical Safety and Pollution 

Prevention. Available on-line at: http://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/guidance-addressingunextracted-pesticide-residues.

64 USEPA. 2014. Toxicity Testing and Ecological Risk Assessment Guidance for Benthic Invertebrates. April 10, 2014. Environmental 

Fate and Effects Division. Office of Pesticide Programs. Office of Chemical Safety and Pollution Prevention. U.S. Environmental 

Protection Agency. Available on-line at: http://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/toxicity-testing-andecological-risk-assessment. 

65 USEPA. 2013. Guidance on Modeling Offsite Deposition of Pesticides Via Spray Drift for Ecological and Drinking Water Assessment. 

Environmental Fate and Effects Division. Office of Pesticide Programs. Office of Chemical Safety and Pollution Prevention. U.S. 

Environmental Protection Agency. Available on-line at: http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2013-0676
Page 32 of 76

Environment Taxa of 

Concern

Exposure 

Pathway

Model(s) or 

Pathway Link

Invertebrate

Contact and 

ingestion of 

residues 

pollen/nectar

Bee-REX

http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticiderisk-assessment#beerex

Plant

Runoff to plants TerrPlant (Run-off)

http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticiderisk-assessment#terrplant 

Residues in 

irrigation water

Results from Aquatic 

Models

http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticiderisk-assessment

Vertebrates Residues in 

aquatic prey items KABAM

http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticiderisk-assessment#kabam

Human 

Health 

EDWC

Vertebrate

Surface Water PWC

PFAM

http://www.epa.gov/pesticide-science-andassessing-pesticide-risks/models-pesticiderisk-assessment

Groundwater PRZM-GW

i. Available Monitoring Data

The Agency is aware of pesticide monitoring conducted by federal and state agencies. This 

information will be considered in the assessment, to the extent that data on PCNB are available. As 

noted earlier, measured residues of PCNB in pollen and nectar will be used to refine dietary-based 

risk estimates for honey bees.

g. Measures of Effect 

The most sensitive toxicity data presented in Section 6 of this problem formulation will be used to 

calculate risk quotients for the respective taxa. Any additional information submitted by the 

registrant or found in the open literature prior to conduct of the risk assessment will also be 

considered. The open literature studies are identified using EPA’s ECOTOXicology database 

(ECOTOX) (USEPA 201566), which employs a literature search engine for locating chemical 

toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of data

that meet the Agency’s standard for inclusion in risk assessments can also provide insight into the 

direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive 

to the chemicals, and from changes in structure and functional characteristics of the affected 

communities.

9. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency 

will evaluate risks to listed species from registered uses of pesticides in Registration Review. The 

process for evaluating potential risks to listed species is further described at 

 

66 USEPA. 2015. ECOTOXicology knowledgebase http://cfpub.epa.gov/ecotox/
Page 33 of 76

http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm. 

10. Endocrine Disruptor Screening Program

PCNB was included in the first group of 67 chemicals issued an order to conduct Tier 1 EDSP 

testing for which EPA has received all of the required Tier 1 assay data. The Agency has 

reviewed all of the assay data received for the appropriate List 1 chemicals and conclusions of 

those reviews are available in the chemical-specific public dockets (see 

http://www2.epa.gov/sites/production/files/2015-06/documents/pcnb-056502_2015-06-

29_txr0057138.pdf). For additional information on the EDSP, visit http://www.epa.gov/endo/.

11. Preliminary Identification of Data Gaps 

a. Environmental Fate

Some of the studies listed below were previously captured as data gaps in the RED67, while others 

reflect either newer data gaps or the need for new data which are of sufficient quality to meet current 

standards for OPP’s risk characterization needs. Additionally, some of the listed studies reflect the 

need for data on the PCNB degradate pentachloroaniline (PCA). These data are needed to more 

completely and accurately characterize the fate and effects of PCNB and its degradates in the 

environment, as well as to assess the potential of the pesticide for long-range transport given that 

its chemical fate properties are consistent with PBT (persistent, bioaccumulative and toxic) 

chemicals.

The environmental fate and ecological risk assessment chapter68 written in support of the RED69

for PCNB characterized the compound as a persistent, moderately volatile compound. Under the 

FAO system, PCNB and its degradates are classified as slightly mobile to hardly mobile. The 

current risk hypothesis for PCNB suggests the chemical and its degradates are persistent (P), 

bioaccumulative (B) and toxic (T); as such, PCNB, viewed collectively with its degradates, has 

properties consistent with chemicals that are termed PBTs. The properties of the PBTs and of 

PCNB as well, lend themselves to long-range atmospheric transport leading to potential exposure 

of non-target organisms distant from registered use sites and resultant accumulation and 

magnification of residues in food chains. However, because of the variability in available data and 

in some cases because of the lack of acceptable data, there is uncertainty regarding the extent to 

which PCNB and its degradates [that retain toxicity] are indeed persistent and prone to 

bioaccumulation and atmospheric transport. Additionally, there is uncertainty regarding the extent 

to which both the parent compound and its degradates are toxic to a broader range of taxa than

those for which there are currently available data. 

Based on environmental fate studies available at the time the RED chapter was written, three major 

degradates of PCNB were identified, i.e., pentachloroanaline (PCA), pentachlorothioanisole 

(PCTA) and pentachlorobenzene (PCB). Of these, PCA is of the most significance due to its 

stability, its mobility, and the magnitude of its concentrations in fate studies relative to the other 

degradates. Several minor degradates were also identified and there was uncertainty regarding the 

extent to which pentachlorophenol (PCP) formed. The chapter identified aqueous photolysis as a 

primary degradation pathway for PCNB when the compound is present in an unsorbed state; 

however, the conditions under which aqueous photolysis can occur at meaningful rates are 

 

67 Ibid USEPA 2006.

68 Ibid USEPA 2005.

69 Ibid USEPA 2006
Page 34 of 76

relatively limited, i.e., clear, shallow water, low in organic matter. The identities of major

photodegradates were not determined in the available studies, and primarily for this reason 

additional aqueous photolysis data are required. Because of its stability in the environment and 

because it is the primary persistent degradate, an aqueous photolysis study of the microbial 

degradate PCA is also necessary. More comprehensive information on the environmental fate 

behavior of PCA would facilitate separate modeling estimates for this main degradate and in doing 

so more accurately characterize the fate of PCNB in aquatic and terrestrial habitats. In the absence 

of these data, EFED has assumed that in general PCNB would degrade to PCA in soil and that the 

PCA would then remain stable to further degradation in both the aquatic and terrestrial 

environments. This assumption is consistent with results seen in submitted fate studies, with PCA 

not decreasing by the time of study termination.

The RED characterized PCNB as moderately volatile; however, there was uncertainty regarding 

the fate of the parent compound and degradates once it had volatilized. Based on air monitoring 

data demonstrating the presence of PCNB and uncertainty regarding the extent to which the 

compound would be subject to photodegradation in the atmosphere (when present in water vapor 

or sorbed to particulates) or atmospheric photo-oxidation, and based on QSAR estimates of 

atmospheric photo-oxidation rates, the parent compound was assumed to be stable and subject to 

atmospheric transport. Given that PCA is the major degradate remaining after microbial 

degradation, and is a volatile compound, photodegradation in air data are being required for both 

PCNB and PCA to more accurately characterize the extent to which either PCNB and/or PCA will 

persist in the atmospheric compartment and be available for long-range transport. In the absence of 

these data, EFED will continue to presume that PCNB is likely to volatilize from applications where 

it is not incorporated into soil, that it will be stable to degradation in the atmosphere, and that it will 

be subject to long-range atmospheric transport. Similar assumptions will be made for PCA. This 

assumption could result in overstating the potential for long-range transport of PCNB and PCA. 

At this time there is uncertainty regarding the extent to which PCNB is subject to biotic degradation 

in both the terrestrial and aquatic environments. The RED characterized the parent as likely to 

biodegrade slowly under aerobic conditions, though noted that PCNB was metabolized more 

rapidly under anaerobic soil conditions. However the anaerobic soil study in question has since 

been downgraded to supplemental because insufficient sampling intervals took place following the 

development of anaerobic conditions to permit the calculation of a valid half-life. Thus the decay 

rate of PCNB under anaerobic conditions is an uncertainty. No guideline aquatic metabolism 

studies are available for PCNB. There is uncertainty regarding the potential formation of PCP and 

pentachlorobenzene (PCB), although the latter is known to be a manufacturing impurity along with 

hexachlorobenzene (HCB) during the production of PCNB. In part because the available studies do 

not adequately characterize the formation and decline of degradation products in soil studies, 

aerobic and anaerobic soil metabolism studies are being required. Because no aquatic metabolism 

data have been submitted, anaerobic aquatic data are also required. In the absence of these data, 

EFED will continue to assume that PCA, PCTA and PCB are major degradates which are stable to 

further degradation and contribute to total persistent residues of PCNB. This assumption could 

result in overstating the persistence of PCNB residues and risk to aquatic and terrestrial organisms.

There is considerable uncertainty regarding the persistence of PCNB on the surface of plants 

(including grasses) following foliar applications. Given that PCNB is moderately volatile and may 

be subject to photolysis, the compound could potentially dissipate rapidly from foliar surfaces. 

Because no data were available on the foliar dissipation of PCNB, the RED relied on the default 
Page 35 of 76

foliar dissipation value of 35 days based on the Willis and McDowell (1987)70 publication. The 

foliar dissipation half-life is used to estimate residues on terrestrial forage items used in estimating 

risk to terrestrial animals. A faster foliar dissipation rate could reduce chronic risk estimates for 

terrestrial animals. Therefore, a special study to document the foliar dissipation half-life of PCNB 

is required. As part of this study, the residues and dissipation rates for the three major degradates 

(PCA, PCTA and PCB) and the minor degradates/contaminants (PCP and HCB) must be quantified. 

It should be noted that a submitted terrestrial field dissipation study of PCNB applied to turf (MRID 

43887403) is inadequate to fulfill this requirement, for a variety of reasons that have been 

previously detailed (DP335819 memo to Jill Bloom, 2/25/2010).

 Photodegradaton in Water (PCNB) (Guideline 835.2240)

 Photodegradaton in Water (PCA) (Guideline 835.2240)

 Photodegradation in Air (PCNB) (Guideline 835.2370)

 Photodegradation in Air (PCA) (Guideline 835.2370)

 Anaerobic Soil Metabolism (PCNB) (Guideline 835.4200)

 Aerobic Soil Metabolism (PCNB) (Guideline 835.4100)

 Aerobic Aquatic Metabolism (PCNB) (Guideline 835.4300)

 Anaerobic Aquatic Metabolism (PCNB) (Guideline 835.4400)

 Foliar Dissipation (PCNB) (Guideline 835.6100SS; Special Study)

 ECM/ILV for Water (PCNB) (Guideline 850.6200)

 ECM/ILV for Soil (PCNB) (Guideline 850.6100)

 ECM/ILV for Sediment (PCNB) (Guideline 850.6100)

Table 10 identifies environmental fate studies by MRID that offer data for each guideline 

requirement, as well as study classifications and whether or not further data are needed in order to 

support risk assessment.

 

70 Willis, Guye H., and Leslie.L. McDowell, 1987. Pesticide Persistence on Foliage. in Reviews of Environmental 

Contamination and Toxicology. 100:23-73.
Page 36 of 76

Table 8. Submitted Environmental Fate Data and Study Classifications for PCNB and Degradates

OCSPP 

Guideline Data Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data needed 

to conduct risk 

assessment?

Justification and Assumptions EPA 

will Make in Absence of Data

835.2120 Hydrolysis 408653-01 

409726-01

acceptable

acceptable No --

835.2240 Aqueous photolysis

426062-01 

426062-02

423362-01

supplemental

supplemental

supplemental

Yes

(PCNB and PCA)

Aqueous photolysis represents a 

relatively rapid degradation pathway for 

parent PCNB, yet the products of 

photolytic degradation of PCNB have 

not been identified. 

835.2410 Soil photolysis 410048-01 

417132-01 acceptable No --

835.4100 Aerobic soil 

metabolism

429119-02 

417132-02

acceptable

acceptable

Yes

(need data for 

PCNB on 3 

additional soils)

90% upper confidence limit on the 

mean half-life will be calculated using 

the available data

835.4200 Anaerobic soil 

metabolism

412036-02 

420944-01

413843-01 

416860-01 

417132-02

supplemental

supplemental

Yes

(PCNB)

Insufficient sampling intervals took 

place following the development of 

anaerobic conditions to permit the 

calculation of a valid half-life. Thus the 

decay rate of PCNB under anaerobic 

conditions is an uncertainty.

835.4300 Aerobic aquatic 

metabolism -- --

Yes

(PCNB)

PCNB TTR will be assumed to be 

stable

835.4400 Anaerobic aquatic 

metabolism -- --

Yes

(PCNB)

PCNB TTR will be assumed to be 

stable

835.1230

835.1240

Adsorption/ 

desorption and 

leaching

416482-01 acceptable

No

(PCNB, PCA, 

PCTA)

--

835.6100 Terrestrial field 

dissipation

430615-01

438874-01

438874-02

438874-03

417214-01

412164-01

424859-01

acceptable

supplemental

supplemental

acceptable

acceptable

acceptable

No --

835.6200 Aquatic field 

dissipation -- -- No --

850.6100 ECM - Soil5-- -- Yes Environmental chemistry methods 

needed for residues in soils.

850.6100 ECM – Sediment5-- -- Yes

Environmental chemistry methods 

needed for residues in benthic 

sediments.

850.6200 ECM – Water5-- -- Yes Environmental chemistry methods 

needed for residues in water.

835.1730 Bioconcentration

405802-02 

412000-01

431793-01

supplemental

supplemental No --

3

ILV=independent laboratory validation

4 ECM=environmental chemistry method

5 LOQ will need to be low enough to ensure detectability at levels of toxicological concern. See ECM guidance (available at ) for 

details.
Page 37 of 76

b. Effects

A number of ecological effect studies are required to address uncertainties regarding the potential 

effects of the parent compound and its primary persistent degradate PCA. Because no registrantsubmitted studies were available to assess the toxicity of PCNB degradates, the ecological risk 

assessment written in support of the RED relied on a combination of open literature and 

(quantitative) structure activity relationships ((Q)SARs) to estimate the toxicity of degradates and 

demonstrate that toxicity estimates for the degradate/contaminants (PCA, PCB, PCP) ranged from 

being as toxic to more toxic than the parent compound. Chronic toxicity data are being 

recommended on the parent compound for estuarine/marine fish and invertebrates. The previous 

assessment identified the missing chronic toxicity data for estuarine/marine animals as a major 

uncertainty and noted that based on acute toxicity estimates, estuarine/marine invertebrates appear 

to be more sensitive than their freshwater counterparts. Vascular and non-vascular aquatic plants 

studies of the parent compound are required as well as seedling emergence and vegetative vigor 

(Tier 1) studies of terrestrial plants. The previous assessment identified terrestrial and aquatic plant 

toxicity data as major uncertainties in the risk assessment. Acute toxicity data are being 

recommended on the PCA degradate for freshwater fish (two species) and invertebrates and 

estuarine/marine invertebrates while chronic toxicity data are recommended on the PCA degradate 

for freshwater fish and invertebrates. The previous assessment identified that structure-activity 

relationship-based estimated toxicity values for the degradates demonstrated considerable 

variability depending on the extent of chlorine substitutions on the benzene ring and as such there 

is uncertainty regarding the extent to which toxicity values for the parent compound are reflective 

of the degradates. Although the previous assessment identified a mysid chronic toxicity study for 

the PCA degradate, EFED will rely on an acute-to-chronic ratio (ACR), based on the recommended 

freshwater invertebrate acute and chronic toxicity data on PCA, to estimate the chronic toxicity of 

PCA to estuarine/marine invertebrates. EFED proposes to apply the freshwater invertebrate ACR 

to the recommended acute toxicity data on PCA for the estuarine/marine mysid to derive the chronic 

toxicity endpoint for the estuarine/marine invertebrate.

Based on the results of the weight-of-evidence (WoE) analysis conducted on PCNB71 as part of the 

EDSP testing, there was limited evidence across the Tier I battery of in vitro and in vivo tests to 

support potential interaction with the estrogen pathway in mammals. However, there was 

complementary evidence within the fish short-term reproduction assay (FSTRA; Guideline 

890.135072) with fathead minnows (Pimephales promelas) to suggest potential interaction with the 

estrogen pathway in wildlife. Exposure to PCNB significantly (p<0.05) decreased fecundity in fish

and there was a concentration-dependent increase (range 42 – 59%) in male gonado-somatic index 

(GSI=weight of the gonad/total body weight); although only observed in the highest treatment 

concentration, there was an increase (35%) in female GSI along with histological changes in the 

ovaries. Therefore, Tier 2 testing with fish, i.e., the medaka (Oryzias latipes) extended one 

generation reproduction test (MEOGRT; Guideline 890.220073) with PCNB is recommended as a 

result of the EDSP Tier 1 assessment. As noted in Table 11, and based on the Code of Federal 

Regulations Part 158, a fish full life cycle study (850.150074) is required for PCNB given its current 

 

71 USEPA 2015a. EDSP Weight of Evidence Conclusions on the Tier 1 Screening Assays for the List 1 Chemicals. 

http://www2.epa.gov/sites/production/files/2015-06/documents/pcnb-056502_2015-06-29_txr0057138.pdf

72 USEPA. 2009. Endocrine Disruptor Screening Program Test Guidelines. OPPTS 890.1350: Fish Short-Term Reproduction Assay. 

Office of Chemical Safety and Pollution Prevention (OCSPP) formerly the Office of Prevention, Pesticides and Toxic Substances (7101). 

EPA 740-C-09-007. October 2009. http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0576-0007

73 USEPA. 2015b. Endocrine Disruptor Screening Program Test Guidelines OCSPP 890.2200: Medaka Extended One Generation 

Reproduction Test (MEOGRT). Office of Chemical Safety and Pollution Prevention (OCSPP) (7101). EPA No. 740.C-15-002. July 

2015. http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0576-0019

74 USEPA. 1996. Ecological Effects Test Guidelines. OPPTS 850.1500 Fish life cycle toxicity. Office of Chemical Safety and 
Page 38 of 76

outdoor uses; however, this data requirement can be fulfilled by successful completion of the 

MEOGRT. In the absence of a MEOGRT, the fish full life cycle study of PCNB is recommended.

The EDSP Tier 1 WoE75 analysis also concluded that there is evidence of potential interaction of 

PCNB with the thyroid pathway in mammals based on alterations in thyroid hormone levels and 

subsequent changes in thyroid histopathology in rats. Since current mammalian toxicity endpoints

used by the human Health Effects Division are more sensitive than doses where effects were seen 

in the mammalian studies examining the thyroid pathway in rats, no additional studies are required 

for mammals at this time. In the amphibian metamorphosis assay (Guideline 890.110076) there was 

a slight but statistically significant (p<0.05) delay in the median tadpole developmental stage at 

Day 21 at all PCNB treatment levels compared to the negative control; however, there were no 

treatment-related effects detected in thyroid histopathology, asynchronous development or 

normalized hind limb length (HLL). Decreases in body weight and snout ventral length (SVL) were 

observe on Day 21 were observed on Day 21 at the high treatment group. Overall, these findings 

did not suggest that the delay in development or decreased growth was thyroid-related. Therefore, 

Tier 2 testing with other wildlife species were not recommended.

Depending on the nature of the sediment, PCNB is expected to partition to variable extents to the 

benthic sediment, and there is uncertainty regarding the extent to which benthic organism may be 

susceptible to effects from exposure to PCNB residues. As such, both acute and chronic toxicity 

tests of aquatic (freshwater and estuarine/marine) invertebrates in the presence of sediment are 

required; the need for chronic studies is dictated by the outcome of the acute toxicity tests. These 

studies are intended to better characterize the toxicity of the parent and its degradate to sedimentdwelling organism that may inhabit areas where the compounds are expected to partition and 

persist. These organisms serve as a point of entry into aquatic food chains and there is uncertainty 

regarding the extent to which residues are bioavailable and toxic to benthic invertebrates. The RED 

assumed that partitioning is likely and that PCNB residues will accumulate and magnify in higher 

trophic levels of the aquatic organisms. Data are recommended on aquatic food chain transfer to 

address uncertainties related to persistence and bioaccumulation in the aquatic environment; this 

study should account for the PCNB parent, PCA and PCDD and PCDF contaminants. These data 

will be useful in addressing that portion of the risk hypothesis for PCNB.

Previous assessments have indicated that PCNB and its degradates are likely to bioaccumulate in 

aquatic food chains. To characterize the extent to which this occurs, EFED recommends an aquatic 

food chain transfer study (OCSPP Guideline 850.1300). A protocol should be submitted for EPA 

review prior to initiating the study. In addition to the parent compound, the study should track the 

primary degradates of PCNB including PCA, PCTA, PCP, PCTASO2 and PCTACO.

Although PCNB is characterized as practically non-toxic to upland game birds and water fowl on 

an acute exposure basis, there is uncertainty regarding the potential effects of the compound on 

passerine species. Since PCNB is formulated as a granule, passerine species may inadvertently 

ingest the product while foraging in treated fields. Therefore, an acute oral toxicity study with 

passerines is recommended. 

 

Pollution Prevention formerly the Office of Prevention, Pesticides and Toxic Substances (7101). EPA 712-C-96_122. April 1996. 

http://www.epa.gov/sites/production/files/2015-07/documents/850-1500.pdf

75 Ibid USEPA 2015a.

76 USEPA. 2009. Endocrine Disruptor Screening Program Test Guidelines OPPTS 890.1100: Amphibian Metamorphosis (Frog). 

Office of Chemical Safety and Pollution Prevention formerly the Office of Prevention, Pesticides and Toxic Substances (7101). EPA 

740-C-09-002. October 2009. http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0576-0002
Page 39 of 76

Although PCNB is characterized as practically non-toxic to honey bees on an acute contact 

exposure basis, additional pollinator toxicity data are needed since the current label allows for 

application to crops that may be in bloom, in which case bees may be exposed. Pending the outcome 

of the lower-tier laboratory-based acute and chronic toxicity studies of individual adult and larval 

honey bees, higher-tier studies, i.e., semi-field (OECD 7577; 850.303078) and full-field (850.304079) 

may be required. Appendix C provides rationales for each of the pollinator-related data. These data 

are consistent with those identified by EPA as providing a foundation for assessing risk potential 

risks to bees80.

Tables 11 and 12 identify ecological effect studies by MRID that offer data for each guideline 

requirement, as well as study classifications and whether or not further data are needed in order to 

support risk assessment. The database for the PCNB TGAI is incomplete. Specific toxicity data are 

not available for many of the degradates; in the absence of toxicity data, the toxicity of these 

compounds will be assumed to be equivalent to parent PCNB.

 Terrestrial plant toxicity data, Tier 1/Tier II (Seedling Emergence and 

Vegetative Vigor) (PCNB TEP) (Guidelines 850.410081 and 850.415082)

 Aquatic plant toxicity data (PCNB TGAI) (Guidelines 850.4400 and 850.5400)

 Estuarine/marine fish life cycle (PCNB TGAI)

 Estuarine/marine invertebrate life cycle (PCNB TGAI) (Guideline 850.135083)

 Whole sediment (PCNB TGAI) (Guidelines 850.173584 and 850.174085; three 

benthic species)

 Whole sediment; chronic (PCNB TGAI) (Special Study)

 Acute toxicity freshwater fish (PCA) (Guideline 850.107586; two species)

 Acute toxicity estuarine/marine fish (PCA) (Guideline 850.1075)

 Mysid Acute Toxicity (PCA) (Guideline 850.103587)

 

77 OECD. 2007. Guidance document on the honey bee (Apis mellifera L.) brood test under semi-field conditions. Series on Testing and 

Assessment No. 75. ENV/JM/MONO(2007)22.

78 USEPA. 2012e. “Honey Bee Toxicity of Residues on Foliage.” Ecological Effects Test Guidelines OCSPP 850.3030. EPA 712-C018. Web. http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0017

79 USEPA. 2012f. “Field Testing for Pollinators.” Ecological Effects Test Guidelines OCSPP 850.3040. EPA 712-C-017. Web. 

http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0018

80 USEPA. 2014. Guidance for Assessing Pesticide Risks to Bees. Office of Pesticide Programs United States Environmental Protection 

Agency, Health Canada Pest Management Regulatory Agency, California Department of Pesticide Regulation. June 19, 2014. 

http://www2.epa.gov/sites/production/files/2014-06/documents/pollinator_risk_assessment_guidance_06_19_14.pdf

81USEPA. 2012a Ecological Effects Test Guidelines. OPPTS 850.4100. Seedling Emergence and Seedling Growth. Office of Chemical 

Safety and Pollution Prevention (7101) EPA 712-C-012. January 2012

82USEPA. 2012b. Ecological Effects Test Guidelines. OPPTS 850.4150. Vegetative Vigor. Office of Chemical Safety and Pollution 

Prevention (7101) EPA 712-C-011. January 2012

83USEPA. 1996a. Ecological Effects Test Guidelines. OPPTS 850.1350. Mysid Chronic Toxicity Test. Office of Chemical Safety and 

Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C96-120 April 1996. 

http://www2.epa.gov/sites/production/files/2015-07/documents/850-1350.pdf

84USEPA. 1996b. Ecological Effects Test Guidelines. OPPTS 850.1035. Whole Sediment Acute Toxicity Invertebrates, Freshwater. 

Office of Chemical Safety and Pollution Prevention formerly the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 

712-C96-354 April 1996. http://www2.epa.gov/sites/production/files/2015-07/documents/850-1735.pdf

85USEPA. 1996c. Ecological Effects Test Guidelines. OPPTS 850.1740. Whole Sediment Acute Toxicity Invertebrates, Marine. Office 

of Chemical Safety and Pollution Prevention formerly the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C96-

355 April 1996. http://www.epa.gov/sites/production/files/2015-07/documents/850-1740.pdf

86USEPA. 1996d. Ecological Effects Test Guidelines. OPPTS 850.1075. Fish Acute Toxicity Test, Freshwater and Marine. Office of 

Chemical Safety and Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C96-118

April 1996. http://www2.epa.gov/sites/production/files/2015-07/documents/850-1075.pdf

87 USEPA. 1996e Ecological Effect Test Guidelines OPPTS 850.1035 Mysid Acute Toxicity Test. Office of Chemical Safety and 

Pollution Prevention (OCSPP) formerly Office of Pollution, Prevention and Toxic Substances (OPPTS) (7101) EPA 712-C-96-136. 

April 1996. http://www2.epa.gov/sites/production/files/2015-07/documents/850-1035.pdf
Page 40 of 76

 Acute toxicity – freshwater invertebrates (PCA) (Guideline 850.101088)

 Fish early life stage – freshwater (PCA) (Guideline 850.140089)

 Fish full life cycle—freshwater (PCNB) (Guideline 850.1500)**

 Aquatic invertebrate life cycle (freshwater) (PCA) (Guideline 850.130090)

 Aquatic Food Chain Transfer (Guideline 850.185091)

 Avian acute oral toxicity – passerine (PCNB TGAI) (Guideline 850.210092)

 Pollinator toxicity data consisting of:

o acute oral test with adult honey bees (PCNB TGAI) (OECD 21393);

o acute honey bee larvae test (PCNB TGAI) (OECD 23794);

o 10-day adult honey bee test (PCNB TGAI) (draft OECD guideline); and,

o 21-day larval honey bee toxicity test (PCNB TGAI) (draft OECD guidance).

o Semi-field whole colony test (PCNB TEP) (OECD 7595)*

o Full-field whole colony test (PCNB TEP) (850.304096)*

o Residues in pollen/nectar (PCNB TEP) (non-guideline)*

*

pending outcome of lower-tier pollinator studies

**fish full life cycle study can be waived pending successful completion of medaka 

extended one generation test (MEOGRT; Guideline 890.2200)

Table 9. Submitted Aquatic Ecological Effects Data and Study Classifications for PCNB.

OCSPP

Guideline

Data 

Requirement

Study 

Type

Submitted Studies 

(MRID)

Study 

Classification

Are data 

needed to 

conduct 

risk 

assessment

Justification and 

Assumptions EPA will 

Make in Absence of 

Data - Some Example 

texts are include

850.1010

Freshwater 

invertebrate 

toxicity

Acute

Waterflea

Daphnia magna

Acc. No. 114167

Valid/satisfied Yes

Current studies are on 

parent PCNB; data are 

needed on the PCA 

degradate.

850.1025

850.1035

850.1045

850.1055 

Saltwater 

invertebrate 

toxicity

Acute

Eastern oyster

Crassostrea 

virginica

408829-02

Supplemental Yes

Current studies are on 

parent PCNB; data are 

needed on the PCA 

degradate; data for PCA 

 

88USEPA. 1996f Ecological Effects Test Guidelines. OPPTS 850.1400. Aquatic Invertebrate Acute Toxicity Test, Freshwater 

Daphnids. Office of Chemical Safety and Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) 

EPA 712-C96-114 April 1996. http://www2.epa.gov/sites/production/files/2015-07/documents/850-1010.pdf

89USEPA. 1996g. Ecological Effects Test Guidelines. OPPTS 850.1400. Fish Early-life Stage Toxicity Test. Office of Chemical Safety 

and Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C96-121 April 1996.

http://www2.epa.gov/sites/production/files/2015-07/documents/850-1400.pdf 

90USEPA. 1996h. Ecological Effects Test Guidelines. OPPTS 850.1300. Daphnid Chronic Toxicity Test. Office of Chemical Safety 

and Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C96-120 April 1996.

http://www2.epa.gov/sites/production/files/2015-07/documents/850-1300.pdf

91USEPA. 1996i. Ecological Effects Test Guidelines. OPPTS 850.1850. Aquatic Food Chain Transfer. Office of Chemical Safety and 

Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C96-133 April 1996. 

http://www2.epa.gov/sites/production/files/2015-07/documents/850-1850.pdf 

92USEPA. 2012c. Ecological Effects Test Guidelines. OPPTS 850.2100. Avian Acute Oral Toxicity Test. Office of Chemical Safety 

and Pollution Prevention former the Office of Prevention, Pesticides and Toxic Substances (7101) EPA 712-C-025. January 2012

93OECD. 1998b. OECD Guidelines for the Testing of Chemicals. Honeybees, Acute Oral Toxicity Test. 213. 

http://lysander.sourceoecd.org/vl=5988235/cl=12/nw=1/rpsv/cgi-bin/fulltextew.pl?prpsv=/ij/oecdjournals/1607310x/v1n2/s14/p1.idx

94OECD. 2013. OECD Guidelines for Testing Chemicals. Honey bee (Apis mellifera) larval toxicity test, single exposure. 

http://www.oecd-ilibrary.org/environment/test-no-237-honey-bee-apis-mellifera-larval-toxicity-test-single-exposure_9789264203723-

en

95 OECD. 2007. Guidance document on the honey bee (Apis mellifera L.) brood test under semi-field conditions. Series on Testing 

and Assessment No. 75. ENV/JM/MONO(2007)22.

96 USEPA. 2012d. “Field Testing for Pollinators.” Ecological Effects Test Guidelines OCSPP 850.3040. EPA 712-C-017.
Page 41 of 76

OCSPP

Guideline

Data 

Requirement

Study 

Type

Submitted Studies 

(MRID)

Study 

Classification

Are data 

needed to 

conduct 

risk 

assessment

Justification and 

Assumptions EPA will 

Make in Absence of 

Data - Some Example 

texts are include

Mysid shrimp

Americamysis bahia

408323-01

Supplemental

should be submitted on 

the estuarine/marine 

mysid.

850.1075 Freshwater fish Acute

Bluegill sunfish

Lepomis 

macrochirus

406180-04

Acceptable

Yes

Current studies are on 

parent PCNB; data are 

needed on the PCA 

degradate. Most sensitive 

fish species from testing 

with PCNB TGAI should 

be used for testing PCA.

Rainbow trout

Oncorhynchus 

mykiss

409927-01

Acceptable

850.1075 Saltwater fish Acute

Sheepshead minnow 

Cyprinodon 

variegatus

408829-03

Acceptable Yes

Current studies are on 

parent PCNB; data are 

needed on the PCA 

degradate.

850.1300

Freshwater 

invertebrates 

life cycle

Chronic

Water Flea

Daphnia magna

413213-01

Acceptable Yes

Current studies are on 

parent PCNB; data are 

needed on the PCA 

degradate.

850.1350

Saltwater 

invertebrates 

life cycle 

Chronic No data Yes Data are needed on parent 

PCNB

850.1400 Freshwater fish 

early-life stage Chronic

Rainbow trout

Oncorhynchus 

mykiss

416634-01

acceptable Yes

Current studies are on 

parent PCNB; data are 

needed on the PCA 

degradate for two species.

850.1400 Saltwater fish 

early-life stage Chronic No data Yes Data are needed on parent PCNB

850.1500 Freshwater fish 

full life cycle Chronic No data Yes

Data requirement can be 

filled pending successful 

completion of OCSPP 

Guideline 890.2200 

(medaka extended one 

generation reproduction 

test)

850.1735

850.1740

10-day 

Sediment 

Toxicity Test

Subacute No data Yes

PCNB is expected to 

partition to sediment; 

sediment toxicity test 

triggered (log Kow≥3; 

Koc≥1000) for Hyalella 

azteca, Chironomus 

tentans, and Leptocheirus 

plumulosus.

Pending outcome of 10-

day study, chronic whole 

sediment tests with 

freshwater and 

estuarine/marine 

invertebrates may be 

needed.
Page 42 of 76

OCSPP

Guideline

Data 

Requirement

Study 

Type

Submitted Studies 

(MRID)

Study 

Classification

Are data 

needed to 

conduct 

risk 

assessment

Justification and 

Assumptions EPA will 

Make in Absence of 

Data - Some Example 

texts are include

850.4400

Aquatic plant 

Toxicity Test 

using Lemna 

minor.

NA Duckweed

Lemna gibba

No data Yes Data are needed on parent 

PCNB

850.5400 Algal toxicity

NA

Green Algae

Pseudokirchneriella 

subcapitata

No data

Yes Data are needed on parent 

PCNB

NA Freshwater Diatom

Navicula pelliculosa

No data

NA

Marine Diatom

Skeletonema 

costatum

No data

850.4550 Cyanobacteria NA

Blue-green Algae

Anabaena flosaquae

No data Yes Data are needed on parent 

PCNB.

Table 12. Submitted Terrestrial Ecological Effects Data for PCNB.

OCSPP 

Guideline

Data 

Requirement

Study 

Type

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed for 

risk 

assessment

Current Additional Data 

Need

850.2100

Avian oral 

toxicity Acute

Northern 

Bobwhite 

quail

Colinus 

virginianus

406180-01

Supplemental No

Passerine Acute No data Yes

PCNB is formulated as a 

granule and could be 

consumed by passerine 

species foraging in treated 

areas.

850.2200 Avian dietary 

toxicity Subacute

Northern 

Bobwhite 

quail

Colinus 

virginianus

406526-02

Acceptable 

No

Mallard duck

Anas 

platyrhynchus

406526--03

Acceptable

850.2300 Avian 

reproduction Chronic

Mallard

Anas 

platyrhynchus

413328-02

Acceptable No
Page 43 of 76

OCSPP 

Guideline

Data 

Requirement

Study 

Type

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed for 

risk 

assessment

Current Additional Data 

Need

Bobwhite

Colinus 

virginianus

413328-01

Acceptable

850.3020

Honey bee 

acute contact 

toxicity

Acute

Honey bee

Apis mellifera

405061-02

409346-01

Acceptable No

Special 

Study

Honey bee 

acute oral 

toxicity

(OECD 213)

Acute No data Yes

Data are needed on parent 

PCNB

Special 

Study

Honey bee 

larval toxicity 

test (OECD 

237)

Acute No data Yes

Special 

Study

Honey bee 

adult 10-day 

toxicity test

Chronic No Data Yes

Special 

Study

Honey bee 21-

day larval 

toxicity test

Chronic No Data Yes

850.3030

Honey bee 

residue on 

foliage

NA No data Yes1

Pending outcome of Tier 1 

tests, studies held in 

reserve.

850.3040 Field testing 

for pollinators Chronic No data Yes1

Pending outcome of Tier 2 

(semi-field studies), fullfield studies held in 

reserve.

Special 

Study

Residues in 

pollen/nectar NA No data Yes

Pending outcome of Tier 1 

tests, studies held in 

reserve.

850.4100 Seedling 

Emergence 

NA No data Yes Data are needed on 

formulated product.

850.4250 Vegetative 

Vigor NA No data Yes Data are needed on formulated product.

* Review of study has not been finalized.
Page 44 of 76

Appendix B. Ecological Model Results

A. Screening Imbibition Model (SIP; version 1.0)

Table 1. Inputs

Parameter Value

Chemical name PCNB

Solubility (in water at 25oC; mg/L) 0.44

Mammalian LD50 (mg/kg-bw) 5050

Mammalian test species laboratory rat

Body weight (g) of "other" mammalian species

Mammalian NOAEL (mg/kg-bw) 200

Mammalian test species laboratory rat

Body weight (g) of "other" mammalian species

Avian LD50 (mg/kg-bw) 2250

Avian test species northern bobwhite quail

Body weight (g) of "other" avian species

Mineau scaling factor 1.15

Mallard NOAEC (mg/kg-diet) 600

Bobwhite quail NOAEC (mg/kg-diet) 600

NOAEC (mg/kg-diet) for other bird species

Body weight (g) of other avian species

NOAEC (mg/kg-diet) for 2nd other bird species

Body weight (g) of 2nd other avian species

Table 2. Mammalian Results

Parameter Acute Chronic

Upper bound exposure (mg/kg-bw) 0.0757 0.0757

Adjusted toxicity value (mg/kg-bw) 3884.2609 153.8321

Ratio of exposure to toxicity 0.0000 0.0005

Conclusion*

Drinking water exposure 

alone is NOT a potential 

concern for mammals

Drinking water exposure 

alone is NOT a potential 

concern for mammals

Table 3. Avian Results

Parameter Acute Chronic

Upper bound exposure (mg/kg-bw) 0.3564 0.3564

Adjusted toxicity value (mg/kg-bw) 1620.9664 29.7675

Ratio of exposure to acute toxicity 0.0002 0.0120

Conclusion*

Drinking water exposure 

alone is NOT a potential 

concern for birds

Drinking water exposure 

alone is NOT a potential 

concern for birds

*Conclusion is for drinking water exposure alone. This does not combine all routes of exposure. Therefore, 

when aggregated with other routes (i.e ., diet, inhalation, dermal), pesticide exposure through drinking water 

may contribute to a total exposure that has potential for effects to non-target animals.
Page 45 of 76

Welcome to the EFED 

Screening Tool for Inhalation Risk

This tool is designed to provide the risk assessor with a rapid method for determining the potential

significance of the inhalation exposure route to birds and mammals in a risk assessment.

Input

Application and Chemical Information

Enter Chemical Name PCNB

Enter Chemical Use Crops

Is the Application a Spray? (enter y or n) y

If Spray What Type (enter ground or air) ground

Enter Chemical Molecular Weight (g/mole) 295.3

Enter Chemical Vapor Pressure (mmHg) 1.13E-04

Enter Application Rate (lb a.i./acre) 10

Toxicity Properties

Bird

Enter Lowest Bird Oral LD50 (mg/kg bw) 2250

Enter Mineau Scaling Factor 1.15

Enter Tested Bird Weight (kg) 0.178

Mammal

Enter Lowest Rat Oral LD50 (mg/kg bw) 5050

Enter Lowest Rat Inhalation LC50 (mg/L) 1.7

Duration of Rat Inhalation Study (hrs) 4

Enter Rat Weight (kg) 0.35

Output

Results Avian (0.020 kg )

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.80E+00

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.26E-01

Adjusted Inhalation LD50 4.22E+00

Ratio of Vapor Dose to Adjusted Inhalation LD50 5.35E-02 Exposure not Likely Significant

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.06E+00

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 2.50E-01 Proceed to Refinements

Results Mammalian (0.015 kg )

Maximum Vapor Concentration in Air at Saturation (mg/m3) 1.80E+00

Maximum 1-hour Vapor Inhalation Dose (mg/kg) 2.84E-01

Adjusted Inhalation LD50 1.01E+02

Ratio of Vapor Dose to Adjusted Inhalation LD50 2.80E-03 Exposure not Likely Significant

Maximum Post-treatment Spray Inhalation Dose (mg/kg) 1.33E+00

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD50 1.31E-02 Exposure not Likely Significant

**NOTE**: When entering values, press the "Enter" key 

in order to update linked cells.
Page 46 of 76

Appendix C. Pollinator Data Requirements

Study Title: Honey bee Adult Acute Oral Toxicity

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

With eusocial bees, pesticide residues may be transferred to pollen and/or nectar of treated plants 

and subsequently brought back to the hive. Therefore, potential acute effects to adult honey bees 

and other insect pollinators from oral exposure to some pesticides could exist. Currently available 

toxicity studies do not address possible effects of oral exposure on adult terrestrial insect survival. 

Because of the potential for pollen and nectar to be contaminated with pesticide residues, and 

subsequently brought back to the hive, it is important to determine the acute oral toxicity of this 

compound to adult honey bees and other insect pollinators.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

bees using the honey bee as a surrogate test species. The guidances discusses Tier 1 laboratorybased acute oral toxicity studies of individual adult bees as a critical component of the screeninglevel risk assessment process for examining potential adverse effects from specific routes of 

exposure. The guidance can be found at: http://www2.epa.gov/pollinator-protection/pollinator-riskassessment-guidance. Additional guidance on the honey bee oral toxicity test design can be found 

in OECD Test Guideline 213 (http://www.oecdilibrary.org/docserver/download/9721301e.pdf?expires=1423074617&id=id&accname=guest&ch

ecksum=2F0764FCB4DCF01D32382952A2E995C3) 

Practical Utility of the Data

How will the data be used?

The Tier 1 acute oral toxicity data on adult honey bees serve as a foundation for the screening-level 

assessment of potential risk non-target organisms such as federally listed threatened or endangered 

and non-listed terrestrial invertebrate insects, including pollinators, from acute oral exposures to 

pesticides. The data will be used to reduce uncertainties associated with the risk assessment for 

terrestrial invertebrates and will improve EPA’s understanding of the potential direct and indirect 

effects on a broad range of taxa. This study will also provide information with which to compare 

whether oral toxicity estimates differ from contact toxicity estimates obtained from other Tier 1

studies. If acute oral effects data for adult honey bees are not available, risks to terrestrial insects 

from acute oral exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or 

is likely to adversely affect listed threatened or endangered species and/or modify their designated 

critical habitat. Without these data, EPA may need to presume risk, which will limit the flexibility 

of pesticide products to comply with FIFRA and the ESA, and could result in use restrictions. 
Page 47 of 76

Study Title: Honey bee Larvae Acute Oral Toxicity

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

With eusocial bees, pesticide residues may be transferred to pollen and/or nectar of treated plants 

and subsequently brought back to the hive where developing larvae and pupae may be exposed. 

Therefore, potential adverse effects to developing bees could result from exposure to pesticide 

residues. Available toxicity studies do not address possible effects on brood (larvae and pupae) 

survival/development. Because of the potential for pollen and nectar to be contaminated with 

pesticide residues, and subsequently brought back to the hive, it is important to determine the acute 

toxicity of this compound to bee brood. 

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

bees using the honey bee as a surrogate test species. The guidances discusses Tier 1 laboratorybased acute toxicity studies of individual honey bee larvae as a critical component of the screeninglevel risk assessment process for examining potential risks from specific routes of exposure. The 

guidance be found at: http://www2.epa.gov/pollinator-protection/pollinator-risk-assessmentguidance. Additional guidance on larval honey bee toxicity test design can be found in OECD Test 

Guideline 237 (http://www.oecdilibrary.org/docserver/download/9713171e.pdf?expires=1422485600&id=id&accname=guest&ch

ecksum=D8E07C2B1DF77BF096C3B29F55BF86A7). In some cases, information pertaining to 

acute toxicity to honey bee larvae may be obtained with the chronic honey bee larval test thereby 

negating the need for separate acute and chronic larval toxicity tests.

Practical Utility of the Data

How will the data be used?

The Tier 1 acute toxicity data on honey bee larvae serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms including federally listed threatened or 

endangered and non-listed terrestrial invertebrates, including pollinators, and/or modify their 

designated critical habitat from acute exposures to pesticides. The data will be used to reduce 

uncertainties associated with the risk assessment for terrestrial invertebrates and will improve 

EPA’s understanding of the potential effects on terrestrial species and whether there is a differential 

sensitivity of larval bees relative to adult bees. If acute effects data for larvae are not available, risks 

to terrestrial insects from acute exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or 

is likely to adversely affect listed threatened or endangered species and/or modify their designated 

critical habitat. Without these data, EPA may need to presume risk which will limit the flexibility 

of pesticide products to comply with FIFRA and the ESA, and could result in use restrictions. 
Page 48 of 76

Study Title: Honey Bee Adult Chronic Oral Toxicity

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

With eusocial bees, pesticide residues may be transferred to pollen and/or nectar of treated plants 

and subsequently brought back to the hive. Therefore, potential chronic effects to adult honey bees 

and other pollinators from oral exposure to some pesticides could exist. Currently available toxicity 

studies do not address possible lethal and sublethal effects of chronic oral exposure on adult 

terrestrial invertebrates and will assist in determining whether the sensitivity of adult bees differs 

from that of earlier life stages. Because of the potential for pollen and nectar to be contaminated 

with pesticide residues, and subsequently brought back to the hive, it is important to determine the 

chronic oral toxicity of this compound to adult honey bees and other pollinators.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

bees using the honey bee as a surrogate test species. The guidances discusses Tier 1 laboratorybased chronic oral toxicity studies of individual adult honey bees as a critical component of the 

screening-level risk assessment process for examining potential risks from specific routes of 

exposure. The guidance can be found at: http://www2.epa.gov/pollinator-protection/pollinatorrisk-assessment-guidance. Although study design elements for the chronic 10-day oral toxicity 

test with honey bees are similar to the OECD TG 213 acute oral toxicity test ( http://www.oecdilibrary.org/docserver/download/9721301e.pdf?expires=1422484908&id=id&accname=guest&ch

ecksum=C38495D2A570AC2216CFB1F223D24AA7), EPA requires that the proposed protocol 

for this study be submitted for review and approval by EPA prior to initiating the test.

Practical Utility of the Data

How will the data be used?

The Tier 1 chronic toxicity data on adult bees serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms including federally listed threatened or 

endangered species and non-listed terrestrial invertebrates, including pollinators, from chronic oral 

exposures to pesticides. The data will be used to reduce uncertainties associated with the risk 

assessment for terrestrial invertebrates and will improve EPA’s understanding of the potential direct 

and indirect lethal and sublethal effects on a broad range of terrestrial species, particularly insect 

pollinators and to determine whether adult toxicity differs substantially from other life stages 

evaluated in other Tier 1 tests. If chronic oral effects data for adults are not available, risks to 

terrestrial insects from chronic exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or 

is likely to adversely affect listed threatened or endangered species and/or their designated critical 

habitat. Without these data, EPA may need to presume risk which will limit the flexibility of 

pesticide products to comply with FIFRA and the ESA, and could result in use restrictions. 
Page 49 of 76

Study Title: Honey Bee Larvae Chronic Oral Toxicity

Rationale for Requiring the Data

Terrestrial invertebrates are likely to be impacted if exposed to pesticides in various use settings. 

For eusocial bees, pesticide residues may be transferred to pollen and/or nectar of treated plants and 

subsequently brought back to the hive where larvae and pupae may be exposed. Therefore, potential 

effects to developing bees could result from chronic exposure to pesticide residues. Available 

toxicity studies do not address possible chronic effects on brood (larvae and pupae) survival. 

Because of the potential for pollen and nectar to be contaminated with pesticide residues, and 

subsequently brought back to the hive, it is important to determine chronic larval/pupal toxicity and 

whether adult emergence is adversely affected. This study will provide information on whether 

honey bee larvae differ in sensitivity from adult bees following chronic exposure.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for 

bees using the honey bee as a surrogate test species. The guidances discusses Tier 1 laboratorybased chronic toxicity studies of individual honey bee larvae as a critical component of the 

screening-level risk assessment process for examining potential risks from specific routes of 

exposure. The guidance can be found at: http://www2.epa.gov/pollinator-protection/pollinator-riskassessment-guidance. Additional information on larval honey bee toxicity repeat exposure test 

design can be found in the OECD draft guidance 

(http://www.oecd.org/env/ehs/testing/Draft_GD_honeybees_rep_exp_for_2nd_CR_25_November

_2013.pdf). Although study design elements for the chronic 21-day toxicity test with honey bee 

larvae have been drafted, EPA requires that the proposed protocol for this study be submitted for 

review and approval by EPA prior to initiating the test. 

Practical Utility of the Data

How will the data be used?

The Tier 1 chronic toxicity data on bee larvae serve as a foundation for the screening-level 

assessment of potential risk to non-target organisms including federally listed threatened or 

endangered and non-listed terrestrial invertebrates, including insect pollinators, from chronic 

exposures to pesticides. These data will be used to reduce uncertainties associated with the risk 

assessment for terrestrial invertebrates and will improve EPA’s understanding of the potential direct 

and indirect lethal and sublethal effects on a broad range of terrestrial species, particularly insect 

pollinators. These data will also assist in determining whether early life stages of the bee differ in 

their sensitivity to pesticides relative to adults. If chronic effects data for larvae are not available, 

risks to terrestrial insects from chronic exposure will be assumed.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued 

registration of a pesticide is likely to result in unreasonable adverse effects to non-target species or 

is likely to adversely affect listed threatened or endangered species and/or modify their designated 

critical habitat. Without these data, EPA may need to presume risk which will limit the flexibility 

of pesticide products to comply with FIFRA and the ESA, and could result in use restrictions. 
Page 50 of 76

Study Title: Semi-field Testing for Pollinators (tunnel or colony feeding studies)

Rationale for Requiring the Data

Tier 2 studies are conditional on the outcome of the screening-level assessment where acute and/or chronic 

risk levels of concern have been exceeded for terrestrial invertebrates. Terrestrial invertebrates are likely to 

be impacted if exposed to pesticides in various use settings. For eusocial bees, pesticide residues may be 

transferred to pollen and/or nectar of treated plants and subsequently brought back to the hive and may 

adversely affect developing brood (egg, larvae, and pupae) and adult bees. Screening-level (Tier 1) studies 

of individual bees do not address possible effects and/or exposure to pesticide residues at the colony-level. 

Because of the potential for pollen and nectar to be contaminated with pesticide residues, and subsequently 

brought back to the hive, it is important to determine whether bee colonies may be negatively affected under 

relatively controlled exposure conditions of a semi-field study. In addition to providing effects data, these 

studies can provide data on pesticide residues in pollen/nectar of treated plants.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for bees using

the honey bee as a surrogate test species. This guidance describes the tiered testing process and can be found 

at: http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance, Additional information on 

honey bee colony studies under semi-field conditions can be found in the OECD Guidance 75 

(http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?cote=env/jm/mono%282007%2922&do

clanguage=en). Due to the complexities of this study, EPA requires that the proposed protocol for this study 

be submitted for review EPA prior to initiating the test.

Practical Utility of the Data

How will the data be used? 

Tier 2 colony-level data will be used to assess potential risk to non-target organisms including listed and 

non-listed terrestrial social invertebrate species and to determine whether effects observed in the screeninglevel (Tier 1) laboratory-based studies of individual bees are evident in colony-level studies under semi-field 

conditions. The Tier2 semi-field test of whole colonies is a relatively controlled study, i.e., bees are confined 

to a specific area, that is designed to represent potential field-level exposure and account for hive dynamics, 

which are not achievable from other pollinator studies. This study will be used to determine whether adverse 

effects to insect pollinators at the whole colony level, may result for the use of pesticides and will help to 

refine risk estimates derived in the screening-level risk assessment for beneficial terrestrial invertebrates. 

Measured residues in pollen/nectar can also be used to refine risk estimates derived from model-based or 

default values in the screening-level assessment.

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued registration 

of a pesticide is likely to result in unreasonable adverse effects to non-target species or is likely to adversely 

affect federally listed threatened or endangered species or their designated critical habitat. Without these 

data, EPA may need to presume risk which will limit the flexibility of pesticide products to comply with 

FIFRA and the ESA, and could result in significant use restrictions. 
Page 51 of 76

Study Title: Semi-field Testing for Pollinators (tunnel or colony feeding studies)

Rationale for Requiring the Data

For eusocial bees, pesticide residues may be transferred to pollen and/or nectar of treated plants and 

subsequently brought back to the hive and may adversely affect developing brood (egg, larvae, and pupae) 

and adult bees. Tier 2 feeding studies are conditional on the outcome of the screening-level assessment where 

acute and/or chronic risk levels of concern have been exceeded for terrestrial invertebrates based on Tier 1

studies of individual bees. Feeding studies utilize free foraging bee colonies that are “dosed” with specific 

quantities of test material and represent a means of ensuring exposure to the test material through spiked 

pollen and/or sugar solutions fed to the colony while still allowing the bees to forage freely. Since bee 

colonies are not confined to enclosures, colonies can be exposed for longer duration periods without 

subjecting the bees to stress that typically results from Tier 2 tunnel studies. Available toxicity studies of 

individual bees (Tier 1) conducted to support screening-level assessments do not address possible effects 

and/or exposure to pesticide residues at the colony-level. It is therefore important to determine whether bee 

colonies may be negatively affected where bees are free foraging and have the option to collect/consume 

alternative forage items beyond the spiked food. Since multiple dose levels can be more readily tested, 

feeding studies can help to define dose-response relationships at the whole colony level.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for bees using

the honey bee as a surrogate. This guidance describes the tiered testing process and can be found at: 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. Additional information on 

honey bee colony feeding studies can be found in the EPPO Guidance 170 

(www.nationalbeeunit.com/downloadDocument.cfm?id=191). Although study design elements for the feeding 

study are available through the EPPO Guidance 170, EPA requires that the proposed protocol for this study be 

submitted for review and approval by EPA prior to initiating the test. 

Practical Utility of the Data

How will the data be used?

Tier 2 colony feeding data will be used to assess potential risk to non-target organisms including listed and 

non-listed terrestrial social invertebrate species. The colony feeding study is designed to represent potential 

field-level exposure and account for hive dynamics using longer duration exposure periods than are possible 

in Tier 2 tunnel studies. This study will be used to determine whether potential adverse effects to insect 

pollinators at the whole colony level when bees are able to forage naturally beyond the spiked food. Results 

from the feeding study will help to refine the screening-level risk assessment for beneficial terrestrial 

invertebrates that were based on Tier 1 studies on individual bees. Since feeding studies can help to define a 

dose-response relationship at the colony level, the studies can provide a means of determining exposure 

thresholds below which the likelihood of adverse effects on colonies may be low.

How could the data impact the Agency’s future decision-making?

The Tier 2 colony-level data will be used to refine screening-level risk estimates derived using Tier 1 

laboratory-based data on individual bees. The Tier 2 data will help to inform the determination required 

under FIFRA or the ESA as to whether continued registration of a pesticide is likely to result in unreasonable 

adverse effects to non-target species or is likely to adversely affect federally listed threatened or endangered 

species or their designated critical habitat. Without these data, EPA may need to presume risk which will 

limit the flexibility of pesticide products to comply with FIFRA and the ESA, and could result in significant 

use restrictions. 
Page 52 of 76

Study Title: Field Testing for Pollinators 

Rationale for Requiring the Data

Tier 3 studies are conditional on the outcome of the screening-level assessment (Tier 1) where acute and/or 

chronic risk levels of concern have been exceeded for terrestrial invertebrates and where Tier 2 studies either 

under semi-field tunnel conditions and/or feeding studies have indicated potential adverse effects at the 

colony level. Available toxicity studies from lower-tier studies do not address possible effects and/or 

exposure to pesticide residues at the colony-level under actual pesticide use conditions and where specific 

uncertainties regarding the likelihood of exposure and/or effects remain. Full-field studies also provide an 

opportunity to measure residues in pollen and nectar as well as various matrices (beebread, honey, wax) 

within the colony to obtain a more realistic understanding of exposure.

The Office of Pesticide Programs has made available a guidance regarding ecological testing for bees using 

the honey bee as a surrogate. This guidance describes the tiered testing process and can be found at: 

http://www2.epa.gov/pollinator-protection/pollinator-risk-assessment-guidance. Additional information on 

honey bee colony studies under full-field conditions can be found in the OCSPP 850.3040 

(http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0018). Useful guidance is also 

available through OCSPP 850.2500 (Field Testing of Terrestrial Wildlife; 

http://www.epa.gov/ocspp/pubs/frs/publications/Test_Guidelines/series850.htm) Although design elements 

for the full-field colony-level study are available through the 850.3040 and 850.2500, EPA requires that the 

proposed protocol for this study be submitted for review and approval by EPA prior to initiating the test; the 

protocol should attempt to address specific uncertainties identified in lower-tier studies.

Practical Utility of the Data

How will the data be used? 

Tier 3 colony-level data will be used to further characterize potential risk to non-target organisms including 

listed and non-listed terrestrial social invertebrate species and to refine screening-level risk estimates that 

were based on individual bee responses. The semi-field test is a controlled study that is designed to represent 

potential field-level exposure under relatively controlled conditions and account for hive dynamics, which 

are not achievable from lower-tier pollinator studies. This study will be used to determine whether adverse 

effects to insect pollinators at the whole colony level, may result for the use of pesticides and will help to 

refine the screening-level risk estimates for beneficial terrestrial invertebrates. This study will also be used 

to determine whether more refined (Tier 3) studies are needed to characterize risk. 

How could the data impact the Agency’s future decision-making?

The data will inform the determination required under FIFRA or the ESA as to whether continued registration 

of a pesticide is likely to result in unreasonable adverse effects to non-target species or is likely to adversely 

affect federally listed threatened or endangered species or their designated critical habitat. Without these 

data, EPA may need to presume risk which will limit the flexibility of pesticide products to comply with 

FIFRA and the ESA, and could result in significant use restrictions. 
Page 53 of 76

Appendix D. Submitted Studies

056502 PCNB Fate/Chemistry Bibliography MRID-Doc# Match

161-1 Hydrolysis

MRID Citation Reference

114176 Iacoviello, S.; Thomas, R. (1978) Analytical Investigations Concerned with the Rate of Hydrolysis of Terraclor Ring 14C(U): 

3346. (Unpublished study received Sep 7, 1982 under 1258-517; 

submitted by Olin Corp., Stamford, CT; CDL:248281-J) 

40506103 Bowman, B.; Fennessey, M. (1987) "Determination of the 

Hydrolysis Rate of 14C-PCNB": ABC Preliminary Report 

#36005. Un- published study prepared by Analytical BioChemistry Laboratories, Inc. 45 p. 

40597301 Bowman, B. (1988) Determination of the Hydrolysis Rate of 14C

-PCNB: ABC Draft Final Report #36005. Unpublished study 

pre- pared by Analytical Bio-Chemistry Laboratories, Inc. 47 p. 

40865301 Bowman, B. (1988) Determination of the Hydrolysis Rate of 14C

-PCNB: Project ID. 36821. Unpublished study prepared by 

Analytical Bio-Chemistry Laboratories, Inc. 304 p. 

40972601 

final report

Bowman, B.; Fennessey, M. (1988) Determination of the 

Hydrolysis Rate of 14C-PCNB: ABC Final Rept. #36005. 

Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 50 p. 

161-2 Photodegradation-water

MRID Citation Reference

142628 Thomas, R. (1983) Photochemical Degradation Studies of 

Terraclor [Ring-[

14C] (U)] (Pentachloronitrobenzene) in 

Aqueous Solution: CASR-3-83. Unpublished study prepared by 

Olin Research Center. 33 p. 

40506104

preliminary

Bowman, B.; Fennessey, M. (1987) Determination of the 

Photolysis Rate of 14C-PCNB in pH-5 Aqueous Solution: ABC 

Preliminary Report #36006. Unpublished study prepared by 

Analytical Bio-Chemistry Laboratories, Inc. 54 p. 

41090701

final

Bowman, B.; Fennessey, M. (1989) Determination of the 

Photolysis Rate of 14C-PCNB in pH-5 Aqueous Solution: Final 
Page 54 of 76

Report: ABC Final Report #36006. Unpublished study prepared 

by Analytical Bio-Chemistry Laboratories, Inc. 62 p. 

41384401

Amended 

report

Dykes, J.; Carpenter, M. (1989) Determination of the Photolysis 

Rate of 14C-PCNB in pH-5 Aqueous Solution: Amended Final 

Report #36822. Unpublished study prepared by Analytical BioChemistry Laboratories, Inc. 1409 p. 

42143001

Interim report

Horree, D. (1991) Aqueous Photolysis of PCNB: Interim Report: 

Lab Project Number: 9127. Unpublished study prepared by 

Uniroyal Chemical Co., Inc. 33 p. 

42336201

final

Horree, D. (1992) Aqueous Photolysis of PCNB: Lab Project 

Number: 9127. Unpublished study prepared by Uniroyal 

Chemical Co., Inc. 51 p. 

42606201 Bashir, M. (1992) Aqueous Photolysis of 14CPentachloronitrobenzene: Lab Project Number: 368223. 

Unpublished study prepared by ABC Labs, Inc. 918 p. 

42606202 Bashir, M. (1992) Aqueous Photolysis of 14CPentachloronitrobenzene: Lab Project Number: 368223A. 

Unpublished study prepared by ABC Labs, Inc. 105 p. 

101794 Hamadmad, N. (1966) Photolysis of Pentachloronitrobenzene, 

2,3,5,6-Tetrachloronitrobenzene, and Pentachlorophenol. 

Doctoral dissertation, Univ. of California--Davis. (Unpublished 

study received Dec 8, 1977 under 464-431; submitted by Dow 

Chemical U.S.A., Midland, MI; CDL:232663-G) In Water or 

Soil

161-3 Photodegradation-soil

MRID Citation Reference

66616 Crosby, D.G.; Moilanen, K.W.; Wong, A.S. (1973) 

Environmental generation and degradation of dibenzodioxins 

and dibenzofurans. Environmental Health Perspectives 

(Sep):259-266. (National Institute of Environmental Science; 

published study; CDL:229320-I) 

101794 Hamadmad, N. (1966) Photolysis of Pentachloronitrobenzene, 

2,3,5,6-Tetrachloronitrobenzene, and Pentachlorophenol. 

Doctoral dissertation, Univ. of California--Davis. (Unpublished 

study received Dec 8, 1977 under 464-431; submitted by Dow 

Chemical U.S.A., Midland, MI; CDL:232663-G) In Water or 

Soil

40972602 

41014201

Bowman, B. (1988) Determination of the Photolysis Rate of 

PCNB on the Surface of Soil: ABC Final Rept. #36007. 
Page 55 of 76

Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 54 p. 

41004801 Carpenter, M.; Bowman, B. (1988) Photodegradation Study of 

14C-PCNB on Soil Surface: ABC Final Report No. 36823. 

Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 313 p. 

41713201 Supplement 

to MRID 

41004801

Kabler, K. (1990) Photodegradation Study of 14C-PCNB on Soil 

Surface: Supplement to MRID 41004801: Lab Project Number: 

368231. Unpublished study prepared by Analytical BioChemistry Labs, Inc. 129 p. 

42841106 

42911901

Misra, B. (1993) PCNB: Photodegradation of 

Pentachloronitrobenzene (PCNB) on a Sandy Loam Soil under 

Artificial Sunlight Irradiation: Final Report: Lab Project No. ME 

9200158. Unpublished study prepared by Pittsburgh 

Environmental Research Lab, Inc. 80 p. 

162-1 Aerobic soil metabolism

MRID Citation Reference

1712 Open lit Ko, W.H.; Farley, J.D. (1969) Conversion of

pentachloronitrobenzene to pentachloroaniline in soil and the 

effect of these compounds on soil microorganisms. 

Phytopathology 59(1):64, 66-67. (Also in unpublished 

submission received Mar 24, 1970 under 9F0754; submitted by 

Olin Mathieson Chemical Corp., New Haven, Conn.; 

CDL:091299-O) 

114171 Beck, J.; Hansen, K. (1974) The degradation of quintozene, pentachlorobenzene, hexachlorobenzene and pentachloroaniline in 

soil. Pestic. Sci. 5:41-48. (Submitter 2300; also In unpublished 

submission received Sep 7, 1982 under 1258-517; submitted by 

Olin Corp., Stamford, CT; CDL:248281-D)

114175 Buser, H.; Bosshardt, H. (1975) Studies on the possible formation 

of polychloroazobenzenes in Quintozene treated soil. Pestic. Sci. 

6:35-41. (Submitter 3236; also In unpublished submission 

received Sep 7, 1982 under 1258-517; submitted by Olin Corp., 

Stamford, CT; CDL:248281-I)

114179 Open lit Wang, C.; Broadbent, F. (1973) Effect of Soil Treatments on 

Losses of Two Chloronitrobenzene Fungicides. J. Environ. 

Quality 2(4): 511-515. (Submitter 3370; also In unpublished 

submission received Sep 7, 1982 under 1258-517; submitted by 

Olin Corp., Stamford, CT; CDL:248281-M) 
Page 56 of 76

114182 Caseley, J. (1968) The loss of three chloronitrobenzene fungicides 

from the soil. Bulletin of Environmental Contamination & 

Toxicology 3(3):180-193. (Submitter 3490; also In unpublished 

submission received Sep 7, 1982 under 1258-517; submitted by 

Olin Corp., Stamford, CT; CDL:248282-A) 

114187 Okazaki, H. (1979) Formation of methyl pentachlorophenyl

sulfoxide and sulfone from pentachloronitrobenzene in soil and 

plants. J. Pesticide Sci. 4:355-360. (Submitter 3577; also In 

unpublished submission received Sep 7, 1982 under 1258-517; 

sub- mitted by Olin Corp., Stamford, CT; CDL:248282-F)

41203601 Daly, D. (1989) Aerobic Soil Metabolism of 14C-Pentachloronitrobenzene: Final Report No. 34904. Unpublished study 

prepared by Analytical Bio-Chemistry Laboratories, Inc. 53 p. 

41384501 Cranor, W. (1989) Aerobic Soil Metabolism of 14C|-pentachloronitrobenzene: ABC Final Report # 36824. Unpublished 

study prepared by Analytical Bio-Chemistry Laboratories, Inc. 

1088 p. 

41713202 Cranor, W. (1990) Aerobic Soil Metabolism of 14C-Pentachloronitrobenzene: Supplement to MRID 41384501: Lab Project 

Number: 368241. Unpublished study prepared by Analytical BioChemistry Labs, Inc. 117 p. 

42112801 Cady, C.; Cranor, W. (1991) Supplement to: Aerobic Soil 

Metabolism of 14C-Pentachloronitrobenzene on Sandy Loam Soil: 

Lab Project Number: 368242. Unpublished study prepared by 

ABC Laboratories, Inc. 270 p. 

42911902 Misra, B. (1993) Aerobic Soil Metabolism of 

Pentachloronitrobenzene (PCNB): Lab Project Number: ME 

9100131. Unpublished study prepared by Pittsburgh 

Environmental Research Lab., Inc. 89 p. 

114180 Open lit Wang, C.; Broadbent, F. (1972) Kinetics of losses of PCNB and 

DCNA in three California soils. Soil Science Society of America 

Proceedings 36(5):742-745. (Submitter 3370; also In unpublished 

submission received Sep 7, 1982 under 1258-517; submitted by 

Olin Corp., Stamford, CT; CDL:248281-N) 

114171 Open lit Beck, J.; Hansen, K. (1974) The degradation of quintozene, pentachlorobenzene, hexachlorobenzene and pentachloroaniline in 

soil. Pestic. Sci. 5:41-48. (Submitter 2300; also In unpublished 

submission received Sep 7, 1982 under 1258-517; submitted by 

Olin Corp., Stamford, CT; CDL:248281-D) 

114175 Open lit Buser, H.; Bosshardt, H. (1975) Studies on the possible formation 

of polychloroazobenzenes in Quintozene treated soil. Pestic. Sci. 

6:35-41. (Submitter 3236; also In unpublished submission 

received Sep 7, 1982 under 1258-517; submitted by Olin Corp., 

Stamford, CT; CDL:248281-I) 
Page 57 of 76

60790 Letter Thomas, R.J. (1969) Letter sent to E.J. Kuchar dated Jun 26, 

1969: Metabolism of PCNB in soil. (Unpublished study, 

including let- ter dated Jun 25, 1969 from E.J. Kuchar to H.H. 

Klein, received Mar 24, 1970 under 9F0754; submitted by Olin 

Mathieson Chem. Corp., New York, N.Y.; CDL:091299-AE) 

162-2 Anaerobic soil metabolism

MRID Citation Reference

41203602 Daly, D. (1989) Anaerobic Soil Metabolism of 14C-Pentachloronitrobenzene: Final Report No. 35905. Unpublished study 

prepared by Analytical Bio-Chemistry Laboratories, Inc. 49 p. 

41384301 Cranor, W.; Patterson, C. (1989) Anaerobic Soil Metabolism of 

Car- bon 14|-pentachloronitrobenzene: ABC Final Report 

#36825. Un- published study prepared by Analytical BioChemistry Laboratories, Inc. 759 p 

41686001 Cranor, W.; Patterson, C. (1990) Amended Final Report to: 

Anaerobic Soil Metabolism of 14C-Pentachloronitrobenzene, 

MRID 41384301: Lab Project Number: #36825. Unpublished 

study prepared by Analytical Bio-Chemistry Laboratories, Inc. 49 

p. 

41713203 

amended report

Cranor, W. (1990) Anaerobic Soil Metabolism of 14CPentachloronitrobenzene: Supplement to and Amended Final 

Report of MRID 413 84301: Lab Project Number: 368251. 

Unpublished study prepared by Analytical Bio-Chemistry Labs, 

Inc. 119 p. 

114178 Murthy, N.; Kaufman, D. (1977) Degradation of 

Pentachloronitrobenzene (PCNB) in Anaerobic Soils: Olin| 3369. 

(U.S. Agricultural Research Service; unpublished study; 

CDL:248281-L) 

42112802 Cady, C.; Cranor, W. (1991) Supplement to: Anaerobic Soil 

Metabolism of 14C-Pentachloronitrobenzene on Sandy Loam Soil: 

Lab Project Number: 368251. Unpublished study prepared by 

ABC Laboratories, Inc. 264 p. 

42094401 White, C.K. (1991) Reply to EPA Rejection of PCNB Anaerobic 

Soil Metabolism Study; MRID#:41203602. Performed and 

Submitted by Uniroyal Chemical Company, Inc.

163-1 Leach/adsorption/desorption

MRID Citation Reference
Page 58 of 76

59118 Thomas, M.P. (1965) Letter sent to H.H. Klein dated Nov 3, 

1965: Olin 2424 and Terraclor residues in soils from 1965 

Terraclor Super X (EC) fall cotton seedling tests run in Texas. 

(Unpublished study received May 28, 1970 under 0F0997; 

submitted by Olin Chemicals, Consumer Products, Div. of Olin 

Corp., Stamford, Conn.; CDL:091717-AA) 

97769 Hartzfeld, E.G. (1965) New Mexico State University Soil 

Persistence Studies. (Unpublished study received May 14, 1965 

under 1258- 279; prepared by New Mexico State Univ., Dept. of 

Botany and Entomology, submitted by Olin Corp., Stamford, 

Conn.; CDL: 101584-E) 

114168 Iacoviello, S. (1978) Chemodynamic Parameter of Terraclor 

(Pentachloronitrobenzene) Soil Adsorption: 1414. (Unpublished 

study received Sep 7, 1982 under 1258-517; submitted by Olin 

Corp., Stamford, CT; CDL:248281-A) 

114173 Registrant 

compilation

Olin Corp. (1965) Data Pertinent to Persistence of Terraclor in 

the Soil: 2322. (Compilation; unpublished study received Sep 7, 

1982 under 1258-517; CDL:248281-F) 

114180 Wang, C.; Broadbent, F. (1972) Kinetics of losses of PCNB and 

DCNA in three California soils. Soil Science Society of America 

Proceedings 36(5):742-745. (Submitter 3370; also In 

unpublished submission received Sep 7, 1982 under 1258-517; 

submitted by Olin Corp., Stamford, CT; CDL:248281-N) 

114181 Esposito, A.; DeFelice, D.; Kuchar, E., et al. (1977) Laboratory 

Soil Leaching Studies Concerned with Terraclor (Pentachlornitrobenzene): 3450. (Unpublished study received Sep 7, 1982 

under 1258-517; submitted by Olin Corp., Stamford, CT; CDL: 

248281-P) 

114966 Dow Chemical Co. (1967) The Results of Tests on the Amount 

of Residue Remaining, Including a Description of the Analytical 

Method Used. (Compilation; unpublished study received Apr 13, 

1967 under 7F0593; CDL:090764-H) 

41648201 Dykes, J. (1990) Soil Adsorption/Desorption with Carbon 14|-

PCNB: Lab Project Number: 38405. Unpublished study prepared 

by Analytical Bio-Chemistry Laboratories, Inc. 509 p. 

43500501 Wu, D. (1994) Adsorption and Desorption of 14CPentachloroaniline in Four Agricultural Soils: Lab Project 

Number: 94039: RPT00210. Unpublished study prepared by 

XenoBiotic Lab., Inc. 120 p. 

43500502 Wu, D. (1994) Adsorption and Desorption of 14CPentachlorothioanisole in Four Agricultural Soils. XBL Study 

No. 94038; XBL Report No. RPT00209. Unpublished Study 
Page 59 of 76

Prepared by Xenobiotic Laboratories, Inc., Plainsboro, NJ and 

Submitted by AMVAC Chemical Corporation, Los Angeles, CA.

65859 and 

5001190

Open lit Helling, C.S., D.G. Dennison and D.D. Kaufman (1974) 

Fungicide Movement in Soils. Phytopathology 64(8):1091-1100. 

Also In Unpublished Submission Received Mar. 5, 1976 under 

6G1754: Submitted by Kalo Laboratories, Inc., Kansas City, 

MO., CDL: 095981-G.

163-2 Volatility - lab

MRID Citation Reference

40506105 

preliminary

Teeter, D. (1988) Laboratory Volatility of PCNB from Soil--

Preliminary Report: ABC #36283. Unpublished study prepared 

by ABC Lab- oratories, Inc. 46 p. 

40580201

final

Teeter, D. (1988) Laboratory Volatility from Soil of PCNB: Final 

Report No. 36283. Unpublished study prepared by Analytical 

Bio-Chemistry Laboratories, Inc. 25 p. 

41178001 Bowman, B. (1989) Laboratory Volatility from Soil of PCNB:

ABC Final Report #37090. Unpublished study prepared by 

Analytical Bio-Chemistry Laboratories, Inc. 311 p. 

42507401 Vithala, R. (1992) Pentachloronitrobenzene: Laboratory 

Volatility Study of PCNB from Soil: Lab Project Number: 

ME9100134: 91148. Unpublished study prepared by Univ. of 

Pittsburgh. 65 p. 

163-3 Volatility - field

MRID Citation Reference

43751101 Merricks, D.; Jensen, M. (1995) PCNB Field Volatility Study: 

Lab Project Number: 1919: 9234: 92-109. Unpublished study 

prepared by Agrisearch Inc. 143 p. 

164-1 Terrestrial field dissipation

MRID Citation Reference

1661 Kuchar, E.J. (1973) Residues of Terraclor (R)I and Terrazole 

(R)I in Soil--1972 Studies: CASR-19-73. (Unpublished study 

received Oct 20, 1976 under 1258-812; submitted by Olin 

Corp., Agricultural Div., Little Rock, Ark.; CDL:228143-X) 
Page 60 of 76

59114 or 

59115

Letter Kuchar, E.J. (1969) Letter sent to H.H. Klein dated Aug 7, 

1969: Soybeans--Emory Fultz--soil. (Unpublished study 

received May 28, 1970 under 0F0997; submitted by Olin 

Chemicals, Consumer Products, Div. of Olin Corp., Stamford, 

Conn.; CDL:091717-P) 

59116 Letter Kuchar, E.J. (1969) Letter sent to H.H. Klein dated Aug 7, 

1969: Soil--PAG Farm, Urbana, Illinois. (Unpublished study 

received May 28, 1970 under 0F0997; submitted by Olin 

Chemicals, Consumer Products, Div. of Olin Corp., Stamford, 

Conn.; CDL:091717-R) 

59118 Letter Thomas, M.P. (1965) Letter sent to H.H. Klein dated Nov 3, 

1965: Olin 2424 and Terraclor residues in soils from 1965 

Terraclor Super X (EC) fall cotton seedling tests run in Texas. 

(Unpublished study received May 28, 1970 under 0F0997; 

submitted by Olin Chemicals, Consumer Products, Div. of 

Olin Corp., Stamford, Conn.; CDL:091717-AA) 

59152 Letter Thomas, M.P. (1965) Letter sent to R.F. Philpitt dated Nov 11, 

1965: Soils from 1965 Terraclor Super X(EC), fall cotton 

seed- ling tests. (Unpublished study received Feb 16, 1968 

under 1258-818; submitted by Olin Corp., Stamford, Conn.; 

CDL: 101585-T) 

59153 Letter Sisken, H.R. (1966) Letter sent to H.H. Klein dated Dec 1, 

1966: PCNB and 2424 residue in cotton. (Unpublished study 

received Feb 16, 1968 under 1258-818; submitted by Olin 

Corp., Stamford, Conn.; CDL:101585-W) 

59154 Letter Sisken, H.R. (1967) Letter sent to H.H. Klein dated Apr 11, 

1967: Degradation of 2424 and PCNB in cotton soil and 

plants. (Unpublished study received Feb 16, 1968 under 1258-

818; submitted by Olin Corp., Stamford, Conn.; CDL:101585-

X) 

97659 Synopsis Mobay Chemical Corporation (1963) Synopsis of Analytical 

and Residue Information for Dexon in Soil Treatment of 

Cotton and Sugar Beets. Summary of studies 005626-B and 

005626-C. (Unpublished study received May 8, 1964 under 

3125-69; CDL:005626-A) 

97663 Compilation Mobay Chemical Corporation (1964) Dexon: Analytical and 

Residue Information of Seed Treatment of Various Vegetable 

Crops. (Compilation; unpublished study received Jun 23, 1964 

under 3125-69; CDL:007027-A) 

97755 Compilation Olin Corporation (1969) PCNB: Residues in Soil|. 

(Compilation; unpublished study received on unknown date 

under 9F0754; CDL: 097474-M) 

97766 Ackermann, H.J.; Hartzfeld, E.G. (1965) Half-life Studies on 

Terra- chlor. (Unpublished study received May 14, 1965 under 
Page 61 of 76

1258- 279; submitted by Olin Corp., Stamford, Conn.; 

CDL:101584-B) 

97767 Referenced 

in fate 

summaryJohnson, G. (1965) Gas Chromatographic Analyses of PCNB 

Treated Soil Samples. (Unpublished study received May 14, 

1965 under 1258-279; prepared by Colorado State Univ., 

Agricultural Experiment Station, Chemistry Section, 

submitted by Olin Corp., Stam- ford, Conn.; CDL:101584-C) 

97768 Referenced 

in fate 

summaryAshworth, L.J.; Price, J.D.; Langley, B.C. (1965) Comparative 

Persistence of Pentachloronitrobenze Formulations in Field 

Soil. (Unpublished study received May 14, 1965 under 1258-

279; pre- pared by Texas A & M Univ., Agricultural 

Experiment Station, Depts. of Plant Sciences and Agricultural 

Analytical Services, Substation No. 20, submitted by Olin 

Corp., Stamford, Conn.; CDL:101584-D) 

97770 Open lit Reinhart, J.H. (1965) Residual effectiveness of dust and 

granular formulations of pentachloronitrobenzene (PCNB). 

Plant Disease Reporter 49(1):60-62. (U.S. Agricultural 

Research Administration, Bureau of Plant Industry, Soils and 

Agricultural Engineering, Div. of Mycology and Disease 

Survey generated; published study; CDL:101584-F) 

114171 open lit Beck, J.; Hansen, K. (1974) The degradation of quintozene, 

penta- chlorobenzene, hexachlorobenzene and 

pentachloroaniline in soil. Pestic. Sci. 5:41-48. (Submitter 

2300; also In unpublished submission received Sep 7, 1982 

under 1258-517; submitted by Olin Corp., Stamford, CT; 

CDL:248281-D)

114172 Kuchar, E.; Griffith, W. (1974) Translocation Studies: 

Terraclor from Treated Soil, Oklahoma: 2315. (Unpublished 

study received Sep 7, 1982 under 1258-517; submitted by Olin 

Corp., Stamford, CT; CDL:248281-E) 

114966 compilation Dow Chemical Co. (1967) The Results of Tests on the Amount 

of Residue Remaining, Including a Description of the 

Analytical Method Used. (Compilation; unpublished study 

received Apr 13, 1967 under 7F0593; CDL:090764-H) 

158311 Letter Thomas, M. (1965) Letter sent to R. Philpitt dated Nov 1, 

1965: Soils from 1965 Terrachlor Super X (EC): fall cotton 

seedling tests. 2 p. 

41210501 Irissarri, G.; Lengen, M. (1989) Field Dissipation of 

Pentachloronitrobenzene on a California Turf Site: Terraclor 

75W: CAR # 69-87; Uniroyal #8785. Unpublished study 

prepared by California Agricultural Research, Inc. in 

cooperation with North Coast Laboratories, Inc. and Uniroyal 

Chemical Co., Inc. 62 p. 

41216401 Rice, F.; Jacobson, B.; Winberry, M. (1989) Terrestrial Field 

Dissipation for PCNB in Broccoli: Project ID's: ABC Final 
Page 62 of 76

Report No. 35969; Uniroyal Project No. 8754B. Unpublished 

study pre- pared by Analytical Bio-chemistry Laboratories, 

Inc. 119 p. 

41216402 Rice, F.; Jacobson, B.; Winberry, M. (1989) Terrestrial Field 

Dissipation for PCNB in Potatoes: Project ID's: ABC Final 

Report No. 35970; Uniroyal Project No. 8754C. Unpublished 

study prepared by Analytical Bio-Chemistry Laboratories, 

Inc. 115 p. 

41313501 Rice, F.; Jacobson, B.; Winberry, M. (1989) Terrestrial Field 

Dissipation for PCNB in Peanuts: ABC Final Report # 35968: 

8754A. Unpublished study prepared by Analytical BioChemistry Laboratories, Inc. 139 p. 

41721401 Judy, D.; Jacobson, B.; Guyton, W. (1990) Terrestrial Field 

Dissipation for PCNB in Potatoes: Final Report: Lab Project 

Number: 36971. Unpublished study prepared by Analytical 

Bio-Chemistry Laboratories, Inc. 1698 p. 

41747001 Rice, F.; Jacobson, B.; Guyton, B. (1990) Terrestrial Field 

Dissipation for PCNB in Broccoli: Lab Project Number: 

36972. Unpublished study prepared by Analytical BioChemistry Laboratories, Inc. 2052 p. 

41752201 Beerbaum, C. (1991) PCNB Residues in Soil Taken 

September, 1990 Following Project No. 8754A: Lab Project 

Number: 90100. Unpublished study prepared by Uniroyal 

Chemical Co., Inc. 23 p. 

42094402 Noon, P. (1990) Storage Stability Study of Terraclor in Soil: 

Lab Project Number: 20.001. Unpublished study prepared by 

North Coast Labs, Inc. 27 p. 

42094403 White, C.K. (1991) Answers to EPA Questions about 

Terraclor Field Dissipation on Turf in California, Uniroyal 

Chemical Project No. 8785, MRID#:41210501. Performed 

and Submitted by Uniroyal Chemical Company, Inc.

42094404 Burger, R. (1991) Confirmation of PCNB and Metabolites for 

Uniroyal Project No. 8785: Field Dissipation of PCNB on a 

California Turf Site: Lab Project Number: 91140. 

Unpublished study prepared by Uniroyal Chem. Co., Inc. 41 

p. 

43061501 Harned, W.; Creeger, S. (1993) Field Dissipation of 

Pentachloronitrobenzene (Terraclor 1OG) in Georgia under 

Conditions for Treatment on Peanuts: Lab Project Number: 

9173. Unpublished study prepared by Georgia Agri-Scientific, 

Inc. and Centre Analytical Labs, Inc. 465 p. 

43887401 Leppert, B. (1995) Pentachloronitrobenzene: Terrestrial Field 

Dissipation of PCNB 10G on Bareground Plot in California: 

Final Report: Lab Project Number: 42126: SARS-94-75: 
Page 63 of 76

SARS-94-CA-75. Unpublished study prepared by ABC Labs, 

Inc. and Stewart Agricultural Services, Inc. 232 p. 

43887402 Leppert, B. (1995) Pentachloronitrobenzene: Terrestrial Field 

Dissipation of PCNB 10G on Bareground Plot in Georgia: 

Final Report: Lab Project Number: 42127: SARS-94-76: 

SARS-94-GA-76. Unpublished study prepared by Stewart 

Agricultural Services, Inc. and ABC Labs, Inc. 217 p. 

43887403 Leppert, B. (1995) Pentachloronitrobenzene: Terrestrial Field 

Dissipation of PCNB 75W on Turfgrass Plot in California: 

Final Report: Lab Project Number: 42128: SARS-94-77: 

SARS-94-CA-77. Unpublished study prepared by Stewart 

Agricultural Services, Inc. and ABC Labs, Inc. 236 p. 

44067701 Saxena, A. (1996) Pentachloronitrobenzene and Metabolites--

Independent Method Validation: Final Report: Lab Project 

Number: N001745-A: SARS-95-78: N001745A. Unpublished 

study prepared by Battelle. 94 p. 

44604501 Harned, W. (1997) Field Dissipation of 

Pentachloronitrobenzene (Terraclor 2 LB Emulsifiable) on 

Cotton in Texas: Lab Project Number: 92147: STBR-92-CT20: 004-26. Unpublished study prepared by South Texas Ag 

Research and Centre Analytical Labs., Inc. 1031 p. 

42485901 White, C. (1992) Answers to EPA Questions about Terraclor 

Field Dissipation on Broccoli in California, Uniroyal 

Chemical Project No. 8754B (MRID 41216401). Unpublished 

study prepared by Uniroyal Chemical Co. 66 p. 

42485902 White, C. (1992) Answers to EPA Questions about Terraclor 

Field Dissipation on Potatoes in Minnesota, Uniroyal 

Chemical Project No. 8754C (MRID 41216402). Unpublished 

study prepared by Uniroyal Chemical Co. 67 p. 

165-0 Accumulation Studies -- General

MRID Citation Reference

114191 Open lit Gile, J.; Gillett, J. (1979) Fate of selected fungicides in a 

terrestrial laboratory ecosystem. J. Agric. Food Chem. 27(6): 

1159-1164. (Submitter 3633; also In unpublished submission received Sep 7, 1982 under 1258-17; submitted by Olin Corp., 

Stamford, CT; CDL:248282-K) 

114195 Open lit Alexander, A. (1979) Pesticide Interactions in the Laboratory 

Rice Paddy Model Ecosystem. Taken from: Dissertation 

Abstracts p. 3567-B-3568-B. (Abstract; Order No. 8004126; 
Page 64 of 76

Submitter 3687; also In unpublished submission received Sep 7, 

1982 under 1258- 517; submitted by Olin Corp., Stamford, CT; 

CDL:248282-O) 

165-1 Confined rotational crop

MRID Citation Reference

41562905 Halls, J.; Timothy, D. (1990) Confined Accumulation Study of 

14C-PCNB on Rotational Crops Treatment, Sampling and 

Combustion Analysis: Lab Project Number: 8755: 35971. 

Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 49 p. 

42599201 Heath, J. (1992) PCNB: Accumulation in Confined Rotational 

Crops: Lab Project Number: 36920. Unpublished study prepared 

by ABC Labs, Inc. 92 p. 

42841101 Overview Putterman, G. (1993) PCNB: Confined Rotational Crops: Study 

Overview. Unpublished study prepared by Uniroyal Chemical 

Co, Inc. 7 p. 

42841102 Registrant 

comments 

+ raw data 

for 

41562905

White, C. (1993) Uniroyal Comments Including Raw Data from 

the In Life Study Entitled: "Confined Accumulation Study of 

(carbon 14)--PCNB on Rotational Crops Treatment, Sampling 

and Combustion Analysis: Lab Project Number: H632. 

Unpublished study prepared by Uniroyal Chemical Co, Inc. 99 p. 

42841103 Murty, V.; Ford, C. (1993) Characterization of 

Pentachloronitrobenzene Metabolites in Rotational Wheat: Lab 

Project Number: 8755: 35971: 9058. Unpublished study prepared 

by Uniroyal Chemical Co, Inc. and ABC Labs. 295 p. 

42841104 Ford, C.; Murty, V. (1993) Characterization of 

Pentachloronitrobenzene Metabolites in Rotational Lettuce: Lab 

Project Number: 8755: 35971: 9039. Unpublished study prepared 

by Uniroyal Chemical Co, Inc. and ABC Labs. 143 p. 

42841105 Ford, C.; Murty, V. (1993) Characterization of 

Pentachloronitrobenzene Metabolites in Rotational Turnip: Lab 

Project Number: 8755: 9055: 35971. Unpublished study prepared 

by Uniroyal Chemical Co, Inc. and ABC Labs. 97 p. 

44348301 Harned, W.; Carter, D.; Parkins, M., et al. (1997) Confined 

Rotational Crop Analytical and Field Study on PCNB: (Final 

Report): Lab Project Number: 9270: RPT00266: 92094. 

Unpublished study prepared by ABC Labs California; Uniroyal 

Chemical Co. Inc.; and XenoBiotic Labs, Inc. 737 p. {OPPTS 

860.1850} 
Page 65 of 76

44577501 

amended report

Harned, W.; Carter, D.; Yu, W., et al. (1998) Confined Rotational 

Crop Analytical and Field Study on PCNB: Amended Final 

Report: Lab Project Number: 9270: 92094: RPT00266. 

Unpublished study prepared by ABC Laboratories California, 

XenoBiotic Laboratories, Inc., Uniroyal Chemical Co., Inc. 969 

p. {OPPTS 860.1850} 

165-2 Field rotational crop

MRID Citation Reference

114187 Okazaki, H. (1979) Formation of methyl pentachlorophenyl 

sulfoxide and sulfone from pentachloronitrobenzene in soil and 

plants. J. Pesticide Sci. 4:355-360. (Submitter 3577; also In

unpublished submission received Sep 7, 1982 under 1258-517; 

sub- mitted by Olin Corp., Stamford, CT; CDL:248282-F)

44081001 Gaydosh, K. (1996) Terraclor 10G Rotational Crop Study: 

Residue Levels of PCNB and Related Metabolites and Impurities 

in Wheat and Lettuce Planted 30 and 120 Days After Terraclor 

10G Applied to Bare Soil at Peanut Application Rates: Lab 

Project Number: RP-92009: KHG-92-004: CRA-92-002. 

Unpublished study prepared by S.T.A.R., Inc.; Hickey's AgriServices Lab; and Centre Analytical Labs., Inc. 535 p. 

44113501 Gaydosh, K. (1996) Terraclor 10G Rotational Crop Study: 

Residue Levels of PCNB and Related Metabolites and Impurities 

in Wheat, Turnip, and Lettuce Planted 365 Days After Terraclor 

10G Applied to Bare Soil at Peanut Application Rates: Lab 

Project Number: RP-91029: KHG-91-068: CRA-91-081. 

Unpublished study prepared by Centre Analytical Laboratories, 

Inc.; S.T.A.R., Inc.; and Hickey's Agri-Services Lab. 693 p. 

165-4 Bioaccumulation in fish

MRID Citation Reference

142629 Wilkes, L.; Iley, E. (1983) Bluegill Sunfish BioconcentrationDepuration Study Using Carbon-14 Labeled PCNB: ADC 

Project #805-1. Unpublished study prepared in cooperation with 

Analytical Development Corp. and Environmental Research and 

Technology, Inc. 62 p. 

40506106

40580202

preliminary

Forbis, A. (1987) Uptake, Depuration and Bioconcentration of 

14C|-PCNB to Bluegill Sunfish (Lepomis macrochirus): 

Preliminary Report #35965. Unpublished study prepared by 

Analytical Bio-Chemistry Laboratories, Inc. 52 p. 
Page 66 of 76

40580202

final

Forbis, A. (1988) Uptake, Depuration and Bioconcentration of 

14C|-PCNB to Bluegill Sunfish (Lepomis macrochirus): Final 

Report No. 35965. Unpublished study prepared by Analytical 

Bio-Chemistry Laboratories, Inc. 37 p. 

41200001 See 

41200000

Burgess, D. (1989) Uptake, Depuration and Bioconcentration of 

14C|-PCNB by Bluegill Sunfish (Lepomis macrochirus): Rept. # 

36872. Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 346 p. 

41200000 Burgess, D. (1989) Uptake, Depuration and Bioconcentration of 

14C-PCNB by Bluegill Sunfish (Lepomis macrochirus). ABC 

Final Report No. 36872. Unpublished Study Performed by 

analytical Bio-Chemistry Laboratories, Inc. and Submitted by 

AMVAC Chemical Corp., Los Angeles, CA.

41521001 Forbis, A. (1990) Bioconcentration of 14C|-PCNB to Channel 

Catfish (Ictalurus punctatus) and Bluegill (Lepomis 

macrochirus) under Static Uptake Conditions: Final Report # 

37033. Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc., Aquatic Toxicology Div. 488 p. 

41951701 Halls, T. (1991) Characterization of 14C-PCNB Residues in 

Water and Bluegill (Lepomis macrochirus) Tissues: Lab Project 

Number: 37024. Unpublished study prepared by ABC Labs, Inc. 

58 p. 

43179301 Vithala, R. (1994) PCNB Metabolite Characterization in Fish and 

Water Samples from a Flow-Through Bluegill Bioconcentration 

Study: Review in Conjunction with MRID 40580202: Lab 

Project Number: 92131: 40366. Unpublished study prepared by 

ABC Labs., Inc. and Uniroyal Chemical Co., Inc. 131 p. 

Non Guideline Selections

1595

14322 

64193

Kuchar, E.J. (1970) Determination of Terraclor (Pentachloronitrobenzene) and Terrazole (5-Ethoxy-3-Trichloromethyl-1,2,4-Thiadiazole) in Soil: Analytical Method. Method CAM-12-70 dated 

Apr 28, 1970. (Unpublished study received May 28, 1970 under 

0F0997; submitted by Olin Corp., Stamford, Conn.; CDL:091717-

B) 

1671 Nadeau, H.G.; Oaks, D., Jr. (1961) Separation and analysis of 

chlorobenzenes in mixtures by gas chromatography. Analytical 

Chemistry 33(9):1157-1159. (Also in unpublished submission 

received Jan 26, 1969 under 9F0754; submitted by Olin Mathieson 

Chemical Corp., New York, N.Y.; CDL:091301-K) 

1672 Harple, W.W. (1966) Infrared Assay Method for 

Pentachloronitrobenzene (PCNB): Analytical Method. Method 

CAM-2-66 dated Jan 26, 1966. (Unpublished study received Jan 

26, 1969 under 9F0754; submitted by Olin Mathieson Chemical 

Corp., New York, N.Y.; CDL:091301-L) 
Page 67 of 76

1673 Finch, R.W.; Nichols, W.A. (1967) Assay of 

Pentachloronitrobenzene by Gas Chromatography: Analytical 

Method. Method CAM-2-67 dated Jan 17, 1967. (Unpublished 

study received Jan 26, 1969 under 9F0754; submitted by Olin 

Mathieson Chemical Corp., New York, N.Y.; CDL:091301-M) 

1676 Geenty, F.O. (1968) Metabolic and Material Balance Study of 

Pentachloronitrobenzene (PCNB) in Cotton Plants: Analytical 

Method CASR-3-68. Method Dated May 3, 1968. Unpublished 

Study Received Jan. 26, 1969 under 9F0754, Submitted by Olin 

Mathieson Chemical Corp., New York, NY, CDL: 091301-2.

1715 Ko, W.H.; Lockwood, J.L. (1968) Accumulation and 

concentration of chlorinated hydrocarbon pesticides by 

microorganisms in soil. Canadian Journal of Microbiology 

14(10):1075-1078. (Also in unpublished submission received Mar 

24, 1970 under 9F0754; sub- mitted by Olin Mathieson Chemical 

Corp., New Haven, Conn.; CDL: 091299-R) 

1716 Chacko, C.I.; Lockwood, J.L.; Zabik, M. (1966) Chlorinated 

hydro- carbon pesticides: Degradation by microbes. Science 

154(3750): 893-895. (Also in unpublished submission received 

Mar 24, 1970 under 9F0754; submitted by Olin Mathieson 

Chemical Corp., New Haven, Conn.; CDL:091299-S) 

14332 

100334

Iacoviello, S.A. (1977) Determination of Terrazole (R)I (5-

Ethoxy- 3-trichloromethyl-1,2,4-thiadiazole) and Terraclor (R)I 

(Penta- chloronitrobenzene) Impurities and Allied Metabolites in 

Water Samples. Method CAM-30-77 dated Jun 1, 1977. 

(Unpublished study received Jul 6, 1979 under 1258-812; 

submitted by Olin Corp., Stamford, Conn.; CDL:238774-B) 

86943 Wainwright, M.; Pugh, G.J.F. (1974) The effects of fungicides on 

certain chemical and microbial properties of soils. Soil Biology 

and Biochemistry 6:263-267. (Also in unpublished submission 

received Nov 17, 1981 under 1023-36; submitted by Upjohn Co., 

Kalamazoo, Mich.; CDL:070503-AX) 

96647 Munnecke, D.E.; Domsch, K.H.; Eckert, J.W. (1962) Fungicidal 

activity of air passed through columns of soil treated with 

fungicides. Phytopathology 52(Dec):1298-1306. (Also in 

unpublished submission received Mar 3, 1982 under 9386-15; 

submitted by Vinings Chemical Co., Atlanta, Ga.; CDL:247007-

B) 

97772 Richardson, L.T.; Munnecke, D.E. (1964) A bioassay for volatile 

toxicants from fungicides in soil. Phytopathology 54(7):836- 839. 

(Also in unpublished submission received May 14, 1965 under 

1258-279; submitted by Olin Corp., Stamford, Conn.; CDL: 

101584-H) 

98854 Domsch, K.H. (1977) The Effect of Fungicidal Agents on Soil 

Respiration. A translation of: (Without title). Phytopathologische 
Page 68 of 76

Zeitschrift 49(3):291-302. (Unpublished study received Jan 4, 

1978 under 239-1246; submitted by Chevron Chemical Co., 

Richmond, Calif.; CDL:232570-M) 

98856 Domsch, K.H. (1972) Interactions of soil microbes and pesticides. 

Symp. Biol. Hung. 11:337-347. (Also in unpublished submission 

received Jan 4, 1978 under 239-1246; submitted by Chevron 

Chemical Co., Richmond, Calif.; CDL:232570-O) 

114189 Kaufman, D. (1975) Persistence and biodegradation of pesticide 

combinations. Roczniki Gleboznawcze XXVI(2):55-64. 

(Submitter 3622; also In unpublished submission received Sep 7, 

1982 under 1258-517; submitted by Olin Corp., Stamford, CT; 

CDL:248282-I) 

5001423 Kilgore, W.W.; White, E.R. (1970) Gas chromatographic 

separations of mixed chlorinated fungicides. Journal of 

Chromatographic Science 8:166-168. 

45228601 Long, S.; Batorewicz, W. (2000) Validation of the Analytical 

Method for the Determination of Pentachloronitrobenzene 

(PCNB) and Pentachloroaniline (PCA) in Water: Lab Project 

Number: AC-7003: 99198. Unpublished study prepared by 

Uniroyal Chemical Company, Inc. 66 p. {OPPTS 850.7100} 

46147101 Feiler, B.; Schocken, M. (2003) Amvac/ Crompton Corporation 

Response to EPA Concerning Pentachlorophenol (PCP) From the 

Fungicide Pentachloronitrobenzene (PCNB). Unpublished study 

prepared by Crompton Manufacturing Company, Inc. 7 p.

3151 Mamadou, D. (1976) Evaluation of a Soil-Plate Screening 

Technique in Developing Fungicidal Control for Southern Stem 

Rot of Peanuts. Master's thesis, North Carolina State Univ., Dept. 

of Plant Pathology. (Unpublished study including abstract, 

received Sep 13, 1976 under 400-129; submitted by Uniroyal 

Chemical, Bethany, Conn.; CDL:225604-AA) 

114193 Isensee, A.; Yockim, R. (1980) Freshwater Micro-ecosystem 

Development and Testing of Substitute Chemicals. By U.S. Dept. 

of Agriculture, Science and Education Administration, Pesticide 

Degradation Laboratory. Duluth, MN: U.S. Environmental 

Protection Agency, Office of Research and Development, 

Environmental Research Laboratory. (EPA-600/3-80-008; 

Contract No. EPA-IAG- 05; Olin 3678; available from: NTIS, 

Springfield, VA: PB80- 151533; published study; CDL:248282-

M) 
Page 69 of 76

PCNB Ecotoxicity Bibliography MRID-Doc# Matchup

71-1 Avian Single Dose Oral Toxicity

MRID Citation Reference

97774 Fletcher, D. (1974) Report to Olin Corporation: Acute Oral 

Toxicity Study with Terra-coat Zn-2055 in Mallard Ducks: IBT 

No. 651- 05846. (Unpublished study received Mar 31, 1975 

under 1258-982; prepared by Industrial Bio-Test Laboratories, 

Inc., submitted by Olin Corp., Stamford, Conn.; CDL:102573-C) 

40618001 Grimes, J.; Jaber, M. (1988) PCNB: An Acute Oral Toxicity 

Study with the Bobwhite: Final Report: Project No. 117-157. 

Unpublished study prepared by Wildlife International Ltd. 39 p. 

40652601 Fletcher, D. (1988) Technical Grade PCNB: 21-day Acute Oral 

LD50 Study in Bobwhite Quail: Rept. No. 88 QD 107. 

Unpublished study prepared by Bio-Life Associates, Ltd. 26 p. 

0160000 Hudson, R.; Tucker, R.; Haegele, M. (1984) Handbook of 

toxicity of pesticides to wildlife: Second edition. US Fish and 

Wildlife Service: Resource Publication 153. 91 p.

71-2 Avian Dietary Toxicity

MRID Citation Reference

2226 Dieterich, W.H. (1965) Acute Dietary Administration-Wildfowl: 

Terraclor Super X: Final Report: Project No. 791-100. 

(Unpublished study received Nov 5, 1965 under unknown admin. 

no.; prepared by Hazleton Laboratories, Inc., submitted by 

Squibb Institute for Medical Research, New Brunswick, N.J.; 

CDL:131392-B) Mallard and Bobwhite studies

59122 Dieterich, W.H. (1965) Letter sent to Sylvan I. Cohen dated Aug 

2, 1965 Review of wildlife testing of Terraclor Super X status|. 

(Unpublished study received Sep 21, 1965 under 1258-740; prepared by Hazleton Laboratories, Inc., submitted by Olin Corp., 

Stamford, Conn.; CDL:050929-C) 

97702 

114164

Fletcher, D. (1973) Report to Olin Corporation: 8-day Dietary 

LC50 Study with Terraclor in Bobwhite Quail: IBT No. 651-

02932. (Unpublished study received Jun 25, 1973 under 1258-
Page 70 of 76

823; prepared by Industrial Bio-Test Laboratories, Inc., submitted 

by Olin Corp., Stamford, Conn.; CDL:005786-B) 

97777 Dieterich, W.H. (1965) Acute Dietary Administration--Wildfowl: 

Project No. 791-100. (Unpublished study received on unknown 

date under unknown admin. no.; prepared by Hazleton Laboratories, Inc., submitted by CDL:103201-A) 

104732 114165 Fletcher, D. (1973) Report to Olin Corporation: 8-day Dietary 

LC50 Study with Terraclor in Mallard Ducklings: IBT No. 651-

02931. (Unpublished study received Jun 25, 1973 under 1258-

823; prepared by Industrial Bio-Test Laboratories, Inc., submitted 

by Olin Corp., Stamford, Conn.; CDL:005786-A) 

40618002 Grimes, J.; Jaber, M. (1988) PCNB: A Dietary LC50 Study with 

the Mallard: Project No. 117-156. Unpublished study prepared by 

Wildlife International Ltd. 39 p. 

40618003 Grimes, J.; Jaber, M. (1988) PCNB: A Dietary LC50 Study with 

the Bobwhite: Project No. 117-155. Unpublished study prepared 

by Wildlife International Ltd. 40 p. 

40652602 Fletcher, D. (1988) Technical Grade PCNB: 9-day Acute Dietary 

LC50 Study in Bobwhite Quail: Rept. No. 88 QC 108. 

Unpublished study prepared by Bio-Life Associates, Ltd. 29 p. 

40652603 Fletcher, D. (1988) Technical Grade PCNB: 9-day Acute Dietary 

LC50 Study in Mallard Ducklings: Rept. No. 88 DC 107. 

Unpublished study prepared by Bio-Life Associates, Ltd. 29 p. 

41061001 Barnhill, H. (1988) Analysis of PCNB Residues in Avian Feed: 

Laboratory Project: HLA 6012-223. Unpublished Study prepared 

by Hazleton Laboratories America, Inc. 15 p. 

71-4 Avian Reproduction

MRID Citation Reference

41321101 Pedersen, C.; Fletcher, D. (1989) PCNB Technical: Toxicity and 

Reproduction Study in Bobwhite Quail: Lab Project Number: 

88/QR/ 30. Unpublished study prepared by Bio-Life Associates, 

Ltd. 153 p. 

41321201 Pedersen, C.; Fletcher, D. (1989) PCNB Technical: Toxicity and 

Reproduction Study in Mallard Ducks: Lab Project Number: 

88/DR/ 27. Unpublished study prepared by Bio-Life Associates, 

Ltd. 147 p. 

41332801 Beavers, J.; Foster, J.; Lattin, A. et al. (1989) 

Pentachloronitrobenzene (PCNB): A One-generation 

Reproduction Study with the Bobwhite (Colinus virginianus): 
Page 71 of 76

Lab Project Number: 117/161. Unpublished study prepared by 

Wildlife International Ltd. 113 p. 

41332802 Beavers, J.; Foster, J.; Lattin, A.; et al. (1989) 

Pentachloronitrobenzene (PCNB): A One-generation 

Reproduction Study with the Mallard (Anas platyrhynchos): Lab 

Project Number: 117/162. Unpublished study prepared by 

Wildlife International Ltd. 115 p. 

43903301 Pedersen, C.; Solatycki, A. (1995) Toxicity and Reproduction 

Study with PCNB Technical in Mallard Ducks: (Final Report): 

Lab Project Number: 146-002-08. Unpublished study prepared 

by Bio-Life Associates, Ltd. 521 p. 

43980301 Pedersen, C.; Solatycki, A. (1995) Toxicity and Reproduction 

Study with PCNB Technical in Bobwhite Quail: Lab Project 

Number: 146-001-07. Unpublished study prepared by Bio-Life 

Associates, Ltd. 729 p. 

72-1 Acute Toxicity to Freshwater Fish

MRID Citation Reference

1572 Dieterich, W.H. (1965) Acute Aqueous Exposure--Fish: Terraclor 

Super X--Final Report: Project No. 791-101. (Unpublished study 

received Nov 5, 1965 under 734-Q; prepared by Hazleton 

Laboratories, Inc., submitted by Squibb Institute for Medical 

Research, New Brunswick, N.J.; CDL:131392-A) Rainbow trout 

and Bluegill sunfish

97773 

114163 

116561

Bentley, R.E. (1974) Acute Toxicity of Terra-coat Zn-2055 to 

Blue- gill (Lepomis macrochirus) and Rainbow Trout 

(Oncorhynchus mykiss formerly Salmo gairdneri). (Unpublished 

study received Mar 31, 1975 under 1258-982; prepared by 

Bionomics, EG & G Environmental Consultants, submitted by 

Olin Corp., Stamford, Conn.; CDL: 102573-A) 

97776 Dieterich, W.H. (1965) Acute Aqueous Exposure--Fish: Project 

No. 791-101. (Unpublished study received on unknown date 

under unknown admin. no.; prepared by Hazleton Laboratories, 

Inc., submitted by CDL:103200-A) 

97778 McCann, J.A. (1967) Terraclor: Bluegill|: Test No. 53. (U.S. 

Agricultural Research Service, Pesticides Regulation Div., 

Animal Biology Laboratory; unpublished study; CDL:103202-A) 

97779 McCann, J.A. (1967) Pentachloronitrobenzene: Methyl Mercury 

Dicyandiamide: Rainbow Trout|: Test No. 43. (U.S. Agricultural 
Page 72 of 76

Research Service, Pesticides Regulation Div., Animal Biology 

Laboratory; unpublished study; CDL:103203-A) 

98672 McCann, J.A.; Pitcher, F. (1973) PCNB 5 Zineb 5 Coated 

Granules: Bluegill (Lepomis macrochirus)|: Test No. 591. (U.S. 

Environmental Protection Agency, Pesticides Regulation Div., 

Animal Biology Laboratory; unpublished study; CDL:129182-A) 

40618004 Surprenant, D. (1988) Acute Toxicity of Pentachloronitrobenzene 

Technical to Bluegill (Lepomis macrochirus) Under Flowthrough Conditions: Report No. 88-4-2697; Study No. 

41.1187.6108.105. Unpublished study prepared by Springborn 

Life Sciences, Inc. 37 p. 

40618005 Surprenant, D. (1988) Acute Toxicity of Pentachloronitrobenzene 

Technical to Rainbow Trout (Oncorhynchus mykiss formerly 

Salmo gairdneri) Under Flow-through Conditions: Report No. 

88-4-2698; Study No. 41.1187.6108.108. Unpublished study 

prepared by Springborn Life Sciences, Inc. 36 p. 

40650301 Surprenant, D. (1988) Acute Toxicity of Terraclor 2EC to 

Rainbow Trout (Oncorhynchus mykiss formerly Salmo gairdneri) 

under Flow-through Conditions: SLS Report #88-5-2727: SLS 

Study #41.0388.6113.108. Unpublished study prepared by 

Springborn Life Sciences, Inc. 39 p. 

40650302 Surprenant, D. (1988) Acute Toxicity of Terraclor 2EC to 

Bluegill (Lepomis macrochirus) under Flow-through Conditions: 

SLS Report #88-5-2725: SLS Study #41.0388.6114.105. 

Unpublished study pre- pared by Springborn Life Sciences, Inc. 

37 p. 

40849001 Swigert, J. (1988) Acute Flow-through Toxicity of PCNB to 

Bluegill Sunfish (Lepomis macrochirus): Final Report #36828. 

Unpublished study prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 169 p. 

40992701 Swigert, J. (1988) Acute Flow-through Toxicity of PCNB to 

Rainbow Trout (Oncorhynchus mykiss formerly Salmo 

gairdneri): Final Report #36829. Unpublished study prepared by 

Analytical Bio-Chemistry Laboratories, Inc. 279 p. 

41060801 Bowman, J. (1989) Acute Flow-through Toxicity of PCNB 2E to 

Blue- gill sunfish (Lepomis macrochirus): Final Report No. 

36937. Un- published study prepared by Analytical BioChemistry Laboratories, Inc. 209 p. 

41060802 Bowman, J. (1989) Acute Flow-Through Toxicity of PCNB 2E to 

Rainbow Trout (Oncorhynchus mykiss formerly Salmo 

gairdneri): Final Report No. 36938. Unpublished study prepared 

by Analytical Bio-Chemistry Laboratories, Inc. 185 p. 

USEPA Animal Biology Laboratory, Beltsville Md. Multiple 

tests with Rainbow trout and Bluegill sunfish
Page 73 of 76

Mostly product mixture tests

72-2 Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

114166 Dive, D.; LeClerc, H.; Persoone, G. (1980) Pesticide toxicity on 

the ciliate protozoan Colpidium campylum: Possible 

consequences of the effect of pesticides in the aquatic 

environment: (Submitter) 3685. Ecotoxicology and 

Environmental Safety 4:129-133. (Also In unpublished 

submission received Sep 7, 1982 under 1258- 517; submitted by 

Olin Corp., Stamford, CT; CDL:248280-H) 

114167 EG & G Bionomics (1982) Acute Toxicity of Terraclor to the 

Water Flea Bionomics Report #BW-82-5-1170; 3761. 

(Unpublished study received Sep 7, 1982 under 1258-517; 

submitted by Olin Corp., Stamford, CT; CDL:248280-I) 

72-3 Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

40832301 Suprenant, D. (1988) Acute Toxicity of Pentachloronitrobenzene 

Technical to Mysid Shrimp (Americamysis bahia formerly 

Mysidopsis bahia) Under Flow-through Conditions: SLS Report 

#88-6-2748: SLS Study #41.1187.6109.515. Unpublished study 

prepared by Springborn Life Sciences, Inc. 38 p. 

40832302 Surprenant, D. (1988) Acute Toxicity of 

Pentachloronitrobenzene Technical to Sheepshead Minnow 

(Cyprinodon variegatus) under Flow-through Conditions: SLS 

Report #88-7-2724: SLS Study #41.1187.61- 09.505. 

Unpublished study prepared by Springborn Life Sciences, Inc. 38 

p. 

40832303

OR

41918801

Surprenant, D. (1988) Acute Toxicity of 

Pentachloronitrobenzene Technical to Eastern Oysters 

(Crassostrea virginica) Under Flow- through Conditions: SLS 

Report #88-4-2701. Unpublished study prepared by Springborn 

Life Sciences, Inc. 39 p. 

40882901 Surprenant, D. (1988) Acute Toxicity of 

Pentachloronitrobenzene to Mysid Shrimp (Americamysis bahia

formerly Mysidopsis bahia) Under Flow-through Conditions: 

Project ID: SLS Report No. 88-7-2773; SLS Study No. 

11857.0488.6100.515. Unpublished study prepared by 

Springborn Life Sciences, Inc. 39 p. 
Page 74 of 76

40882902 Surprenant, D. (1988) Acute Toxicity of Pentachloronitobenzene 

(PCNB) to Eastern Oysters (Crassostrea virginica) Under Flowthrough Conditions: Project ID: SLS Report No. 88-6-2760; SLS 

Study No. 11857.0488.6101.504. Unpublished study prepared by 

Springborn Life Sciences, Inc. 43 p. 

40882903 Surprenant, D. (1988) Acute Toxicity of 

Pentachloronitrobenzene to Sheepshead Minnow (Cyprinodon 

variegatus) Under Flow-through Conditions: Project ID: Report 

No. 88-7-2764; SLS Study No. 11857.0488.6100.505. 

Unpublished study prepared by Springborn Life Sciences, Inc. 39 

p. 

41918801

OR

40832303

Shepherd, S. (1991) Raw Data to Support the Study Entitled:

Acute Toxicity of Pentachloronitrobenzene Technical to Eastern 

Oysters (Crassostrea virginica) under Flow-through Conditions: 

Supplement to MRID 40832303: Lab Project Number 88-4-

2701: 41-1187- 6110-130. Unpublished study prepared by 

Springborn Labs. 7 p. 

41926101 Suprenant, D. (1988) Raw Data for Acute Toxicity of 

Pentachloronitrobenzene (PCNB) to Eastern Oysters 

(Crassostrea virginica) under flow-through conditions: Lab 

Project Number: 88-6-2760-504. Unpublished study prepared by 

Springborn Laboratories, Inc. 29 p. 

42336901 Bettencourt, M. (1992) Pentachloronitrobenzene (PCNB) 

Technical: Acute Toxicity to Sheepshead Minnow (Cyprinodon 

variegatus) under Flow-through Conditions: Lab Project 

Number: 92-4-4244. Unpublished study prepared by Springborn 

Laboratories, Inc. 60 p. 

40228401 USEPA Gulfbreeze Laboratory 1986. Sheepshead minnow test

72-4 Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

40832304 Surprenant, D. (1988) The Chronic Toxicity of 

Pentachloronitrobenzene Technical to Daphnia magna Under 

Flow-through Conditions: Report #88-5-2711. Unpublished 

study prepared by Springborn Life Sciences, Inc. 49 p. 

40884001 Surprenant, D. (1988) The Toxicity of Pentachloronitrobenzene 

Technical to Fathead Minnow (Pimephales promelas) Embryos 

and Larvae: Project ID: SLS Report No.88-9-2803; SLS Study 

41.1187.6111.120. Unpublished study prepared by Springborn 

Life Sciences, Inc. 49 p. 

41321301 Burgess, D. (1989) Chronic Toxicity of PCNB to Daphnia 

magna under Flow-through Test Conditions: Lab Project 
Page 75 of 76

Number: 36830. Unpublished study prepared by Analytical BioChemistry Laboratories, Inc. 342 p. 

41663401 Cohle, P.; Herzig, R. (1990) Early Life Stage Toxicity of PCNB 

to Rainbow Trout (Oncorhynchus mykiss) in a Flow-through 

System: Lab Project Number: 36871. Unpublished study 

prepared by Analyst Bio-chemistry Labs., Inc. 1203 p. 

41918802 Shepherd, S. (1991) Raw data to Support the Study Entitled: The 

Toxicity of Pentachloronitrobenzene Technical to the Fathead 

Minnow (Pimephales promelas) Embryos and Larvae: 

Supplement to MRID 40884001: Lab Project Number: 88-9-

2803: 41-1187-6111-130. Unpublished study prepared by 

Springborn Labs. 30 p. 

41918803 Shepherd, S. (1991) Raw data to Support the Study Entitled: The 

Chronic Toxicity of Pentachloronitrobenzene Technical to 

Daphnia magna under Flow-through Conditions: Supplement to 

MRID 408323- 04: Lab Project Number: 88-5-2711: 41-1187-

6112-130. Unpublished study prepared by Springborn Labs. 46 

p. 

141-1 Honey bee acute contact

MRID Citation Reference

40506102 Hoxter, K.; Jaber, M. (1987) PCNB: An Acute Contact Toxicity 

Study with the Honey Bee: Project No.: 117-154A. Unpublished 

study prepared by Wildlife International, Ltd. 15 p. 

40934601 Hoxter, K.; Jaber, M. (1988) PCNB: An Acute Contact Toxicity 

Study with the Honey Bee: Wildlife International Ltd. Project 

No. 246-101B. Unpublished study prepared by Wildlife 

International Ltd. 26 p. 

Non Guideline Selctions

2267 Hansing, E.D. (1966) Effect of Seed Treatment on Emergence of 

Winter Wheat and Control of Bunt, Manhattan, Kansas, 1966. 

(Unpublished study received Feb 16, 1968 under 1258-813; 

submitted by Olin Corp., Stamford, Conn.; CDL:005784-BF) 

13099 Haglund, W.A. (1968) To Determine the Effect of EDB and 

Chloropicrin on the Emergence and Survival of New Era Peas 

Grown in the Greenhouse. (Unpublished study including letter 

dated Oct 29, 1968 from W.A. Haglund to Bill Carroll, received 

Jan 31, 1969 under 5785-39; prepared by Washington State Univ., 

Northwestern Washington Research and Extension Unit, 

submitted by Great Lakes Chemical Corp., West Lafayette, Ind.; 

CDL:007782-C) 
Page 76 of 76

97758 Borzelleca, J.F. (1974) Subchronic Oral (Dietary) Toxicity of 

Terraclor in Chickens. (Unpublished study received May 31, 1974 

under 1F1083; prepared by Medical College of Virginia, Div. of 

Toxicology, submitted by Olin Corp., Stamford, Conn.; 

CDL:098613-A) 

98850 Tews, L.L. (1971) The effects of selected fungicides and soil 

fumigants upon the microfungi of a cattail marsh. Proc. 14th Conf. 

Great Lakes Res. 14:128-136. (Also in unpublished sub-mission 

received Jan 4, 1978 under 239-1246; submitted by Chevron 

Chemical Co., Richmond, Calif.; CDL:232570-G) 

5006642 Kappelman, A.J., Jr.; Buchanan, G.A. (1968) Influence of 

fungicides, herbicides and combinations on emergence and 

seedling growth of cotton. Agronomy Journal 60(6):660-662. 

Laboratory Mammal Data (check with HED)

23469301

23469302

23469303

Phillips, R. (1994) Two generation reproduction toxicity study in 

rats with pentachloronitrobenzene (PCNB) (MRD-89-505). Exxon 

Biomedical Sciences, Inc. Toxicology Laboratory, East Millstone, 

New Jersey. Laboratory Project ID No. 150535, June 1, 1994. 

MRID 43469301, 43469302, 43469303. Unpublished.