United States Chemical Safety December 2011 

Environmental Protection and Pollution Prevention 

Agency (7510P) 

 

o-Benzyl-p-Chlorophenol 

Registration Review: 

Final Work Plan 

December 2011 
Docket Number: EPA-HQ-OPP-2011-0423 

www.regulations.gov 

o-Benzyl-p-Chlorophenol 

Registration Review: 

Final Work Plan 

December 2011 

Case # 2045 

Approved By: 

J an Harrigan-Farrelly 

irector, Antimicrobials Division 

Date: / ,t/ 'J-{) @II 

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o-Benzyl-p-Chlorophenol Registration Review Team

Human Health & Environmental Effects

Nathan Mottl 

Najm Shamim 

Risk Management

Rebecca von dem Hagen 

Lance Wormell 

Office of General Counsel

Phil Ross 

________________________________________ 

Supporting documents for the o-Benzyl-p-Chlorophenol Case may be found in the registration 

review docket EPA-HQ-OPP-2011-0423 located on the internet at www.regulations.gov. 
Docket Number: EPA-HQ-OPP-2011-0423 

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Introduction

This is the Final Work Plan (FWP) of the Environmental Protection Agency (EPA or “the 

Agency”) for the registration review of o-benzyl-p-chlorophenol (Case 2045). The work plan 

includes the expected registration review timeline. The work plan also addresses public 

comments received concerning the Preliminary Work Plan (PWP) in the Summary Document 

which was posted in the o-benzyl-p-chlorophenol registration review docket, and any other 

comments concerning the initial docket postings. The Summary Document provided information 

on what EPA knows about the pesticide and what additional risk analyses and data or 

information the Agency believes are needed to make a registration review decision. 

The Agency is implementing the registration review program pursuant to Section 3(g) of the 

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and will review each registered 

pesticide every 15 years to determine whether it continues to meet the FIFRA standard for 

registration. Changes in science, public policy and pesticide use practices will occur over time. 

The registration review program is intended to make sure that, as the ability to assess risk 

evolves and as policies and practices change, all registered pesticides continue to meet that 

statutory standard. The public phase of registration review begins when the initial docket is 

opened for each case. Information on this program is provided at: 

http://www.epa.gov/oppsrrd1/registration_review/. 

The o-Benzyl-p-Chlorophenol Case (Case Number 2045) includes three active ingredients, obenzyl-p-chlorophenol (PC Code 062201) and its salts, potassium o-benzyl-p-chlorophenol (PC 

Code 062202) and sodium o-benzyl-p-chlorophenol (PC Code 062203). The first product 

containing o-benzyl-p-chlorophenol as an active ingredient was registered in the United States in 

1948. Currently, there are 38 o-benzyl-p-chlorophenol, 3 potassium o-benzyl-p-chlorophenol, 

and 5 sodium o-benzyl-p-chlorophenol products registered with the EPA. 

O-benzyl-p-chlorophenol and salts products are registered as disinfectants, fungicides/fungistats, 

tuberculocides, sanitizers, virucides, bacteriocides/bacteriostats, microbiocides/microbiostats and 

algaecides. O-benzyl-p-chlorophenol and salts products are registered for use as hard non porous 

surface disinfectants and deodorizers in agricultural premises and equipment, commercial, 

institutional and industrial premises, food handling processing equipment and premises, and 

residential and public access areas such as horse stables, meat and poultry processing plants, 

mushroom houses, greenhouses, households, and animal kennels. O-benzyl-p-chlorophenol and 

salts are also registered for use as hard non porous surface disinfectant in medical areas and 

equipment such as non conductive floors, beds, wall and floors and to pre-clean instruments and 

other medical equipment prior to terminal sterilization. In addition, the technical product is 

registered for use as a material preservative in metalworking fluids, rubber goods, leather, 

textiles, upholstery fabrics, and carpets. The technical product and two additional end-use 

products are registered for use in water treatment systems such as air washers, recirculating 

cooling water towers, sewage systems, grease traps, drains, and human drinking water 

equipment. The material preservative uses are not listed on any end-use product labels. There is 

one sodium o-benzyl-p-chlorophenol end-use product registered for use in recirculating cooling 
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water systems and air washers. EPA has established tolerances under 40 CFR § 180.940(c)1

 for 

o-benzyl-p-chlorophenol’s use in food processing equipment and utensils not to exceed 320 ppm. 

FDA has cleared o-benzyl-p-chlorophenol as an indirect additive in food contact sanitizing 

solutions (21 CFR §178.1010) that can be used for food processing equipment and utensils. 

The o-benzyl-p-chlorophenol Preliminary Work Plan (PWP) was published on June 29, 2011 and 

the 60-day comment period ended on August 29, 2011. Documents associated with the 

registration review of o-benzyl-p-chlorophenol and salts can be viewed at www.regulations.gov 

in docket EPA-HQ-OPP-2011-0423. The Agency completed a Reregistration Eligibility 

Decision (RED) for o-benzyl-p-chlorophenol and salts in 1995. 

Comments Received on the Preliminary Work Plan

The Agency received two comments during the public comment period on the initial docket, 

described below. One comment resulted in a change to the anticipated human health data 

requirements. Based on the comment submitted by Physicians Committee for Responsible 

Medicine, the Agency intends to accept either a multigeneration or an extended one-generation 

reproduction and fertility effects study (870.3800) to support the risk assessments planned for 

registration review instead of a multigeneration reproduction and fertility effects study 

(870.3800), as discussed below. In the PWP, the Agency solicited comments on specific topics: 

environmental justice, water body impairment, trade irritants, and structure activity relationships. 

No comments or information were received during the public comment period concerning these 

issues. 

Comment: The Physicians Committee for Responsible Medicine (PCRM) commented 

that conducting the special study for dermal sensitization anticipated as being required in 

the PWP “raises serious ethical and scientific concerns.” The commenters state that 

based on research, including a 1986 patch test, researchers found that “different doses of 

sensitizing substances in general induce variable expressions in the human population, 

making the identification of a sensitization threshold that can protect all populations 

extremely difficult from human data, much less from the animal study the agency 

proposes to require.” Also, the commenter suggests the Agency utilize cell-based 

alternatives. They urge the Agency to request a Local Lymph Node Assay (LLNA) in 

place of the currently anticipated study because of the assay’s animal welfare advantages. 

PCRM submitted multiple studies from the literature that could be utilized by the Agency 

for the anticipated Immunotoxicity (870.7800) and Multigeneration Reproduction and 

Fertility Effects (870.3800) studies. If the studies on the reproductive effects of obenzyl-p-chlorophenol do not satisfy the Multigeneration Reproduction and Fertility 

Effects data gap, the commenter argues that the effects will be evident in the first 

generation; therefore, a one-generation test should be required instead of a 

multigeneration test. 

 

1

 Tolerance listed in 40 CFR § 180.940(c) is for Phenol, 4-chloro-2-(phenylmethyl)-, an alternative name for obenzyl-p-chlorophenol, CAS Reg. No. 120-32-1. This tolerance only applies only to o-benzyl-p-chlorophenol, not 

the potassium and sodium salts. 
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Response: As noted in the Summary of Human Health Effects Data for the o-Benzyl-pChlorophenol (OBPC) Registration Review Decision Document,, a dermal sensitization 

study using multiple concentrations of o-benzyl-p-chlorophenol is anticipated as being 

being required based on the use of this chemical in textiles, upholstery fabrics, and 

carpets where repeated dermal contact will occur. This study is necessary for the planned 

human health risk assessment because there is a known positive dermal sensitization 

response observed in the traditional guinea pig test the Agency requires for all pesticide 

registrations. The available animal data do not establish a concentration to quantitatively 

assess dermal sensitization for human health risk assessment. The published study of 

Stern et al. (1991) utilized mice in the ear swelling assay, which is not an acceptable 

assay for the Agency to assess dermal sensitization. The Stern et al. study also utilized 

dermabrasion, which the Agency considers unacceptable in studies involving dermal 

application of test materials. 

Currently, there are no validated in vitro or cell-based assays that the Agency can use to 

determine dermal sensitization potential or potency. The Local Lymph Node Assay 

(LLNA), which is stated in the OCSPP 870.2600 guideline as one of the acceptable 

assays for dermal sensitization assessment may not be appropriate for strong dermal 

irritants such as o-benzyl-p-chlorophenol, and also only measures the induction phase of 

dermal sensitization. 

Based on a preliminary review of the 1986 human patch test study by Sonnex and 

Rycroft mentioned in PCRM's letter, the study does not provide sufficient information to 

fulfill the data requirement; therefore, the Agency continues to anticipate the need to 

require a quantitative dermal sensitization study. The Agency will consider all submitted 

information during the registration review risk assessments. 

With respect to PCRM's comments on the immunotoxicity and reproductive toxicity data 

requirements, the Agency encourages the registrants to submit these studies in response 

to the data call-in associated with this registration review. At that time, the Agency will 

review the information to determine if the requirements for immunotoxicity and 

reproductive toxicity data are adequately met. The Agency agrees with PCRM that an 

extended one-generation reproductive and fertility effects study will provide the Agency 

with sufficient information to support the human health risk assessment planned for the 

o-benzyl-p-chlorophenol registration review. The Agency will accept a multigeneration 

or an extended one-generation reproductive and fertility effects study (870.3800) The 

“Anticipated Human Health Data Needs” section in this FWP has been updated to reflect 

this change. . 

Comment: The technical registrant of o-benzyl-p-chlorophenol submitted a comment 

stating that the company intends to submit a request for deletion of the material 

preservative use of o-benzyl-p-chlorophenol in metalworking fluids, rubber goods, 

leather, textiles, upholstery fabrics and carpets. Lanxess believes that the removal of 

these uses will result in changes to the data requirements anticipated for this registration 

review. The registrant also believes the need for the immunoxicity study currently 
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anticipated as required should be reevaluated and the registrant states that they would like 

to discuss this further with the Agency. 

In addition, the registrant noted that several of the data justifications in the Product 

chemistry, Environmental Fate and Eco-effects Scoping Document for Registration 

Review of: Ortho-Benzyl-Para-Chlorophenol and Sodium and Potassium Salts state that 

the anticipated data is triggered by o-benzyl-p-chlorophenol’s use as a wood preservative. 

However, this chemical is not registered as a wood preservative. 

Response: Upon receipt of the registrant’s request to terminate o-benzyl-p-chlorophenol’s 

use as a material preservative in metalworking fluids, rubber goods, leather, textiles, 

upholstery fabrics and carpets, the Agency will initiate the use termination process 

pursuant to FIFRA Section 6(f). Should these use terminations become final and 

effective, the Agency expects that the anticipated data needs will change. Until the 

Cancellation Order is complete, the Agency continues to anticipate the need to require the 

data as described in the PWP. The Agency is willing to discuss the anticipated 

immunotoxicity data requirement and encourages the registrant to request a meeting with 

the Agency. 

In regards to the comment on the study justifications included in the Product chemistry, 

Environmental Fate and Eco-effects Scoping Document for Registration Review of: 

Ortho-Benzyl-Para-Chlorophenol and Sodium and Potassium Salts, the Agency has 

confirmed that o-benzyl-p-chlorophenol is not registered for use as a wood preservative 

and that the references in the Scoping Document were errors. The study justifications 

will be updated to reference the correct uses that trigger the data requirements. 

The comments did not affect the work plan and timeline described in the PWP and they remain 

as they were presented initially in the PWP. Further, this document makes final the work plan 

for the o-benzyl-p-chlorophenol registration review process. 

Anticipated Risk Assessments and Data Needs

The Agency anticipates the need to conduct a comprehensive ecological risk assessment, 

including an endangered species risk assessment, for all uses of o-benzyl-p-chlorophenol and 

salts. The Agency anticipates the need to conduct a human health risk assessment. The Agency 

anticipates needing additional data for use in conducting the registration review for o-benzyl-pchlorophenol. 

Ecological Risk Assessment Status and Anticipated Data Needs 

 A quantitative environmental risk assessment was not performed for o-benzyl-pchlorophenol for the 1995 RED because at that time the Agency anticipated that potential 

release into the environment would be regulated under the NPDES program and would 

not result in significant exposure to wildlife. 

 The Agency anticipates the need to require the following additional ecological data for 

use in conducting the registration review of o-benzyl-p-chlorophenol and salts. 
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850.1010 -- Aquatic invertebrate acute toxicity, freshwater daphnids 

850.1025 -- Oyster acute toxicity test2

850.1055 -- Bivalve acute tox larval (embryo/larval)2

850.1035 -- Mysid acute toxicity test 

850.1300 -- Daphnid chronic toxicity test 

850.1400 -- Fish early-life stage toxicity test (freshwater) 

850.5400 -- Algal Toxicity Tier I and Tier II (green algae) 

850.1710 -- Aquatic Bioavailability/Biomagnification: Oyster BCF 

850.1730 -- Aquatic Bioavailability/Biomagnification: Fish BCF 

 The Agency anticipates the need to require the following additional environmental fate 

data for use in conducting the registration review of o-benzyl-p-chlorophenol and salts. 

835.2120 -- Hydrolysis

835.2240 -- Photodegradation in water

835.1110 -- Activated Sludge Sorption Isotherm 

850.6800 – Modified activated sludge, respiration inhibition test3

835.3110 -- Ready biodegradability3

835.3220 -- Porous Pot Test3

835.3280 -- Simulation Tests to Assess the Biodegradability of Chemicals 

Discharged to Wastewater3

835.3240 -- Simulation Test - Aerobic Sewage Treatment: A. Activated Sludge 

Units3 For more information, please refer to Revised Product chemistry, 

Environmental Fate and Eco-effects Scoping Document for Registration Review 

of: Ortho-Benzyl-Para-Chlorophenol and Sodium and Potassium Salts, located in 

the docket. 

Human Health Risk Assessment Status and Anticipated Data Needs 

 The most recent human health risk assessment for o-benzyl-p-chlorophenol and salts was 

completed in support of the 1995 RED. 

Dietary Assessment

 The Agency anticipates the need to conduct a dietary (food) risk assessment for o-benzylp-chlorophenol based on indirect exposure to surface cleaners and a dietary (drinking 

water) assessment based on the potential for o-benzyl-p-chlorophenol to pass through 

 

2

 The anticipated DCI will give registrants the option to undertake testing for either 850.1025 or 850.1055. 3

 The results of the Activated Sludge Respiration Inhibition Test (ASRI) expected to be required will determine 

which of these three biodegradation tests would be anticipated to be required. If the ASRI test EC50 is less than or 

equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or Simulation Test – Aerobic Sewage 

Treatment: A. Activated Sludge Units or the Porous Pot Test would be anticipated to be required. If the ASRI test 

EC50 is greater than 20 mg/L, then the applicant would choose to conduct either: (i) Ready Biodegradability or (ii) a) 

Biodegradation in Activated Sludge or b) Simulation Test – Aerobic Sewage Treatment: A. Activated Sludge Units 

or c) the Porous Pot Test. If the Ready Biodegradability study is conducted and passes, then no further testing 

would be expected to be required. If, however, the antimicrobial fails the Ready Biodegradability study, then the 

Biodegradation in Activated Sludge or Simulation Test – Aerobic Sewage Treatment: A. Activated Sludge Units, or 

the Porous Pot study would be expected to be required. 
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waste water treatment plants. 

 A dietary risk assessment was not conducted for the 1995 RED because at that time the 

U.S. Department of Agriculture and the EPA determined that disinfectants requiring a 

potable water rinse, when applied to surfaces in federally inspected meat, poultry, and 

egg processing plants, do not present dietary exposure risks (USDA, FSIS publication 

#1419, "List of Proprietary Substances and Nonfood Compounds"). EPA now conducts 

dietary risk assessments for disinfectant uses even when a potable rinse is employed. This 

decision is a result of recent behavioral research that supports that not all consumers carry 

out a potable water rinse. To further support the need for a dietary risk assessment, it has 

also been concluded that potable water rinses are not efficient at removing residues to a 

negligible level, and in fact remain on the surface and may result in human exposure. 

This change is also a result of the 1996 signing of the Food Quality Protection Act 

(FQPA). 

Tolerances and International Harmonization

 EPA has established tolerances under 40 CFR § 180.940(c)4 for o-benzyl-pchlorophenol’s use in food processing equipment and utensils not to exceed 320 ppm. 

FDA has cleared o-benzyl-p-chlorophenol as an indirect additive in food contact 

sanitizing solutions (21 CFR §178.1010) that can be used for food processing equipment 

and utensils. 

Occupational and Residential Assessment and Risk

 The Agency anticipates the need to conduct occupational and residential human health 

risk assessments for the registration review of o-benzyl-p-chlorophenol. The Agency 

anticipates that occupational handler exposure may occur through application of obenzyl-p-chlorophenol as disinfectant with a wet-mist fogger. Dermal and incidental oral 

postapplication exposure may also occur from children crawling on treated floors, or 

hand-to-mouth exposure from counter tops and floors. 

 Occupational and occupational post-application exposure risk assessments were 

performed for the 1995 RED. 

 As a result of the 1995 RED, EPA intended to require application exposure data to 

confirm that application of o-benzyl-p-chlorophenol in a fogging device would not pose 

unreasonable risks to workers through dermal or inhalation exposure. The Agency 

determined that until the data were received, full-face respiratory protection as well as 

complete dissipation of the mist and thorough ventilation of the enclosed area before 

reentering a treated area would be specified for all o-benzyl-p-chlorophenol fogging 

products. Amended labels reflecting the label changes outlined in the RED were 

submitted by registrants along with the information required through the post-RED 

product-specific data call-in (PDCI); therefore, EPA reregistered the products. However, 

 

4

 Tolerance listed in 40 CFR § 180.940(c) is for Phenol, 4-chloro-2-(phenylmethyl)-, an alternative name for obenzyl-p-chlorophenol, CAS Reg. No. 120-32-1. This tolerance only applies only to o-benzyl-p-chlorophenol, not 

the potassium and sodium salts. 
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a post-RED generic data call-in for o-benzyl-p-chlorophenol was never issued and 

application exposure data have not yet been required. The Agency expects to require 

these data through registration review. 

Aggregate and Cumulative Exposure and Risk

 The Agency has not conducted an aggregate risk assessment for o-benzyl-p-chlorophenol 

and salts. 

 EPA does not have, at this time, available data to determine whether o-benzyl-pchlorophenol has a common mechanism of toxicity with other substances or how to 

include this pesticide in a cumulative risk assessment. For the purposes of this 

Registration Review, EPA has assumed that o-benzyl-p-chlorophenol does not have a 

common mechanism of toxicity with other substances when used as an antimicrobial as 

registered. 

Anticipated Human Health Data Needs

 The Agency anticipates the need to require the following additional human health data 

for use in the registration review of o-benzyl-p-chlorophenol and salts. 

Special Study -- Skin (dermal) sensitization 

870.3465 -- 90-day inhalation toxicity (rat) 

870.3800 -- Reproduction and fertility effects (multigeneration or extended one- 

 generation) - rat 

870.7800 -- Immunotoxicity 

875.1200 -- Dermal indoor exposure 

875.1400 -- Inhalation indoor exposure 

875.1600 -- Application exposure data reporting and calculations 

875.1700 -- Product use information 

875.2800 -- Description of human activity 

875.2300 -- Indoor surface residue dissipation 

875.2500 -- Inhalation exposure 

875.3000 -- Nondietary ingestion exposure 

 For more information, including information on the use patterns triggering each data 

requirement, please refer to Summary of Human Health Effects Data for the o-Benzyl-pChlorophenol (OBPC) Registration Review Decision Document, located in the docket. 

Product Chemistry Data Needs 

 The Agency does not anticipate the need to require additional product chemistry data for 

this registration review at this time. 

o For more information, please refer to Product chemistry, Environmental Fate and 

Eco-effects Scoping Document for Registration Review of: Ortho-Benzyl-ParaChlorophenol and Sodium and Potassium Salts, located in the docket. 
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Incidents:

Ecological: 

 There are no reported incidences in the Agency’s Ecological Incidence Information System 

(EIIS) regarding o-benzyl-p-chlorophenol and salts. 

Human Health: 

 The OPP Incident Data System (IDS) has reported 122 human incidents attributable to obenzyl-p-chlorophenol. Most of the incidents are classified as moderate incidents. Severe 

dermal irritation and allergic type reactions were reported. The symptoms included skin 

depigmentation, itching, pain, swollen, blister, hives, and erythema. Reported symptoms 

related to inhalation exposures included nasal irritation, ulcerated nasal membranes, burning 

throat, blisters in throat, hoarse coughing, shortness of breath, coughing, dyspnea, chest pain, 

and chest tightness. 

 Acute systemic effects for workers included nausea, dizziness, stomach ache, headache, 

vertigo, and soft stool. For longer exposures over 6-months, workers complained of no or 

low appetite, weakness, and liver damage. Severe autoimmune thrombocytopenia, red skin 

rashes, nose/mouth bleeding, aplastic anemia and leukemia was also reported. 

 One incident that raised a reproductive concern, involved a pregnant woman. The baby was 

born 6 weeks early with too much fluid in the abdomen. The baby died as a result. 

Endangered Species 

The Agency has not conducted a risk assessment that supports a complete endangered species 

determination for o-benzyl-p-chlorophenol and salts. The ecological risk assessment planned 

during registration review will allow the Agency to determine whether o-benzyl-p-chlorophenol 

and salts’ use has 'no effect' or 'may affect' federally listed threatened or endangered species 

(listed species) or their designated critical habitats. When an assessment concludes that a 

pesticide’s use 'may affect' a listed species or its designated critical habitat, the Agency will 

consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Services (the 

Services), as appropriate. 

Endocrine Disruptor Screening Program 

As required by FIFRA and FFDCA, EPA reviews numerous studies to assess potential adverse 

outcomes from exposure to chemicals. Collectively, these studies include acute, subchronic and 

chronic toxicity, including assessments of carcinogenicity, neurotoxicity, developmental, 

reproductive, and general or systemic toxicity. These studies include endpoints which may be 

susceptible to endocrine influence, including effects on endocrine target organ histopathology, 

organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, reproductive loss, 

and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests and 

chronic studies that assess growth, developmental and reproductive effects in different 

taxonomic groups. As part of the 1995 Reregistration Eligibility Decision for o-benzyl-p-
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chlorophenol and salts, EPA reviewed these data and selected the most sensitive endpoints for 

relevant risk assessment scenarios from the existing hazard database. However, as required by 

FFDCA section 408(p), o-benzyl-p-chlorophenol and salts are subject to the endocrine screening 

part of the Endocrine Disruptor Screening Program (EDSP). 

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect. 

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients and 9 inert ingredients. O-benzyl-pchlorophenol and salts are not among the group of 58 pesticide active ingredients on the initial 

list to be screened under the EDSP. Accordingly, as part of registration review, EPA will issue 

future EDSP orders/data call-ins, requiring the submission of EDSP screening assays for obenzyl-p-chlorophenol and salts. For further information on the status of the EDSP, the policies 

and procedures, the list of 67 chemicals, future lists, the test guidelines and the Tier 1 screening 

battery, please visit our website: http://www.epa.gov/endo/. 

Timeline

EPA has created the following estimated timeline for the completion of the o-benzyl-pchlorophenol registration review: 

Anticipated Schedule

Activities Estimated Month/Year

Phase 1: Opening the docket 

Open Public Comment Period for Docket Completed 

June 2011 

Close Public Comment Period for Docket Completed 

August 2011 

Phase 2: Case Development 

Develop Final Work Plan (FWP) Completed 

December 2011 

Issue DCI December 2012 

Data Submission December 2014 

Open Public Comment Period for Preliminary Risk Assessments June 2016 
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Close Public Comment Period for Preliminary Risk Assessments July 2016 

Phase 3: Registration Review Decision 

Open Public Comment Period for Proposed Reg. Review Decision December 2016 

Close Public Comment Period for Proposed Reg. Review Decision February 2017 

Final Decision and Begin Post-Decision Follow-up 2017 

Total (years) 6 

Next Steps

A DCI will be developed regarding the data needs listed under the “Anticipated Risk 

Assessments and Data Needs” section of this document. The Agency expects to issue the DCI in 

December 2012. Human health and ecological risk assessments will be conducted for all uses. 

 
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Summary of Anticipated Data Requirements – o-Benzyl-p-Chlorophenol

The table below summarizes anticipated data needs for the registration review of o-benzyl-pchlorophenol. 

Table 1. Summary of Anticipated Data Requirements – o-Benzyl-p-Chlorophenol 

Guideline 

Number Anticipated Data Requirement Test Material 

Estimated 

Timeframe 

(Measured in 

months from 

DCI Receipt) 

Special 

Study 

Skin (Dermal) Sensitization TGAI 12 

870.3465 90-day Inhalation Toxicity TGAI 24 

870.3800 Reproduction and Fertility Effects 

(multigeneration or extended one-generation) TGAI 24 

870.7800 Immunotoxicity TGAI 24 

875.1200 Dermal Exposure – Indoor TGAI 24 

875.1400 Inhalation Exposure - Indoor TGAI 24 

875.1600 Data Reporting and Calculations TGAI 24 

875.1700 Product Use Information (Handler) TGAI 12 

875.2800 Product Use Information (Postapplication) TGAI 12 

875.2300 Indoor Surface Residue Dissipation TGAI 12 

875.2500 Inhalation Exposure TGAI 24 

875.3000 Non-dietary Ingestion TGAI 12 

835.2120 Hydrolysis TGAI 12 

835.2240 Photodegradation in water TGAI 12 

835.1110 Activated Sludge Sorption Isotherm TGAI 12 

850.6800 

Modified activated sludge, respiration inhibition 

test 5 TGAI 12 

 

5

The results of the Activated Sludge Respiration Inhibition Test (ASRI) expected to be required will determine 

which of these three biodegradation tests would be anticipated to be required. If the ASRI test EC50 is less than or 

equal to 20 mg/L, then either the Biodegradation in Activated Sludge Study or Simulation Test – Aerobic Sewage 

Treatment: A. Activated Sludge Units or the Porous Pot Test would be anticipated to be required. If the ASRI test 

EC50 is greater than 20 mg/L, then the applicant would choose to conduct either: (i) Ready Biodegradability or (ii) a) 

Biodegradation in Activated Sludge or b) Simulation Test – Aerobic Sewage Treatment: A. Activated Sludge Units 
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835.3110 Ready Biodegradability5 TGAI 12 

835.3220 Porous Pot Test5 TGAI 12 

835.3240 

Simulation Test – Aerobic Sewage Treatment: A. 

Activated Sludge Units5 TGAI 12 

835.3280 

Simulation Tests to Assess the Biodegradability of 

Chemicals Discharged to Wastewater5 TGAI 12 

850.1010 Aquatic invertebrate acute toxicity, freshwater 

daphnids TGAI 12 

850.1025 Oyster acute toxicity test6 or TGAI 12 

850.1055 Bivalve acute tox larval4 (embryo/larval) TGAI 12 

850.1035 Mysid acute toxicity test TGAI 12 

850.1300 Daphnid chronic toxicity test TGAI 18 

850.1400 Fish early-life stage toxicity test (freshwater) TGAI 18 

850.5400 Algal Toxicity Tier I and Tier II (green algae) TGAI 12 

850.1710 Aquatic Bioavailability/Biomagnification: Oyster 

BCF TGAI 18 

850.1730 Aquatic Bioavailability/Biomagnification: Fish 

BCF TGAI 18 

 or c) the Porous Pot Test. If the Ready Biodegradability study is conducted and passes, then no further testing 

would be expected to be required. If, however, the antimicrobial fails the Ready Biodegradability study, then the 

Biodegradation in Activated Sludge or Simulation Test – Aerobic Sewage Treatment: A. Activated Sludge Units, or 

the Porous Pot study would be expected to be required. 

6

 The anticipated DCI will give registrants the option to undertake testing for either 850.1025 or 850.1055.