United States Chemical Safety February 2012 

Environmental Protection and Pollution Prevention 

Agency (7510P) 

 

Glycine, N-(Hydroxymethyl)-Monosodium Salt 

(SHMG) 

Registration Review: 

Final Work Plan 

February 2012 

 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov 

Glycine, N-(Hydroxymethyl)-Monosodium Salt 

(SHMG) . 

Registration Review: 

Final Work Plan 

February 2012 

Case # 5030 

Approved By: 

oan Harrigan-F relly 

Director, Antimicrobials Division 

Date: 

I I 

20[14 

" 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

3 of 14 

SHMG Registration Review Team

Human Health & Environmental Effects

William Hazel 

Srinivas Gowda 

Risk Management

Rebecca von dem Hagen 

Lance Wormell 

Office of General Counsel

Philip Ross 

________________________________________ 

Supporting documents for the Glycine, N-(Hydroxymethyl)-Monosodium Salt Case may be found 

in the registration review docket EPA-HQ-OPP-2011-0615 located on the internet at

www.regulations.gov. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

4 of 14 

Introduction

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

Agency”) for the registration review of Glycine, N-(hydroxymethyl)-monosodium salt (SHMG) 

(Case 5030). 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 Glycine, N-(hydroxymethyl)-monosodium salt 

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 first product containing Glycine, N-(hydroxymethyl)-, monosodium salt (PC Code 128972), 

also known as sodium hydroxymethylglycinate or SHMG, as an active ingredient was registered 

in the United States in 1997. Currently, there is only one product containing SHMG registered 

with EPA. This product, Suttocide A 50% Solution (EPA Reg. No. 57978-4), is a biocidal agent 

registered for use to inhibit the growth of bacteria and fungi. It is registered for use as a material 

preservative in liquid soaps, fabric cleaning and care products, water based cleaning products, 

waterborne coatings and polishes, water based adhesives, printing supplies, and textile 

emulsions. SHMG can also be used as a preservative in cosmetics. Cosmetic uses are not 

regulated by EPA. 

SHMG’s mechanism of antimicrobial action appears to be largely or wholly via release of 

formaldehyde (HCHO). In a 2002 “Opinion,” The EU’s Scientific Committee on Cosmetic and 

Non-food Products Intended for Consumers (SCCNFP) indicated that, in aqueous solution, 

SHMG is rapidly decomposed to formaldehyde and sodium glycinate. Glycine/sodium glycinate 

is the simplest amino acid, is naturally occurring in humans, is one of the basic 20 components of 

protein, and is not of toxicological concern. Formaldehyde is being evaluated as an active 

ingredient separately under registration review Case 0556. EPA anticipates the need to require 

additional data on SHMG for use in assessing risk from the parent compound (i.e., SHMG) 

and/or formaldehyde. 

SHMG is not registered for use in products that may come in direct contact with food. No 

tolerance or tolerance exemption has been established in food as a result of use as a direct or 

indirect food additive, as an active ingredient, or as an inert ingredient. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

5 of 14 

The SHMG Preliminary Work Plan (PWP) was published on September 20, 2011 and the 60-day 

comment period ended on November 29, 2011. EPA did not complete a reregistration eligibility 

decision (RED) for SHMG because the first pesticide product containing SHMG was registered 

after November 1, 1984. Documents associated with the registration review of SHMG can be 

viewed at www.regulations.gov in docket EPA-HQ-OPP-2011-0615. 

Comments Received on the Preliminary Work Plan

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

described below. In the PWP, the Agency solicited comments on specific topics: environmental 

justice, water body impairment, trade irritants, and structure activity relationships. No comments 

were received during the public comment period concerning these issues. 

Comment: “We encourage the registrant to pursue possible waivers for the 90-day dermal 

toxicity study, the 90-day inhalation toxicity study, and the reproduction and fertility 

effects study (multigeneration). The Human Health Scoping Document indicates that the 

reproduction and fertility effects study may be waived but the Summary Document does 

not. We also wish to highlight the following data that can be found in an MSDS. 

Reproductive/Developmental Toxicity: 

Oral; Rat; 150, 300 or 450 mg/kg/day for 9 days; not teratogenic or embryotoxic 

(100% sodium hydroxymethylglycinate). 

If this study and the waiver option are deemed unacceptable then we recommend the use 

of OECD TG 443 Extended One-Generation Reproductive Toxicity Study (EOGRTS), 

which uses about half the number of animals as the traditional Reproduction and Fertility 

Effects guideline. The test guideline is currently available on the OCED website.” 

Response: As noted in the Summary of Product Chemistry, Environmental Fate, and 

Ecotoxicity Data for the Glycine, N-(hydroxymethyl)-monosodium salt Registration 

Review Decision Document, “if the recommended environmental fate studies demonstrate 

to EPA’s satisfaction that SHMG rapidly and completely degrades to HCHO and glycine, 

the subchronic dermal and inhalation toxicity studies may be waived. Similarly, if the 

recommended environmental fate studies demonstrate to EPA’s satisfaction that SHMG 

rapidly and completely degrades to HCHO and glycine such that residues of concern will 

not be expected to contaminate drinking water, the two-generation reproductive toxicity 

study may be waived.” A footnote explaining the option of a waiver for the twogeneration reproductive toxicity study was inadvertently omitted from the Preliminary 

Work Plan and has been included in this FWP. 

In addition, the Agency encourages the registrants to submit relevant studies and 

applicable waivers 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 reproductive 

toxicity data requirement is adequately met or can be waived. 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 SHMG registration review. The Agency will accept a 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

6 of 14 

multigeneration or an extended one-generation reproductive and fertility effects study. 

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

reflect this change. 

The comment received during the initial public comment period resulted in the changes 

described above. The comments did not otherwise affect the data needs, work plan and timeline 

described in the PWP. Further, this document makes final the work plan for the SHMG 

registration review process. 

Risk Assessments and Anticipated Data Needs

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

including an endangered species risk assessment, for all uses of SHMG. The Agency also 

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

additional data for use in conducting the registration review for SHMG. 

Ecological Risk Assessment Status and Data Needs 

 No ecological risk assessment has been performed for SHMG. 

 The Agency anticipates the need to require the following ecological effects data for use in 

the registration review of SHMG. 

850.5400 -- Algal Toxicity Tier II using freshwater green alga, 

Selenastrum capricornutum 

 The Agency anticipates the need to require the following environmental fate data for use 

in the registration review of SHMG. 

835.1110 -- Activated Sludge Sorption Isotherm 

835.2120 -- Hydrolysis 

835.2240 -- Photodegradation in Water 

850.6800 -- Modified Activated Sludge, Respiration Inhibition Test1

835.3110 -- Ready Biodegradability1

835.3220 -- Porous Pot Test1

835.3240 -- Simulation Test – Aerobic Sewage Treatment: A. Activated Sludge Units1

835.3280 -- Simulation Tests to Assess the Biodegradability of Chemicals Discharged 

to Wastewater1

 

1

 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. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

7 of 14 

 For more information, please refer to Summary of Product Chemistry, Environmental 

Fate, and Ecotoxicity Data for the Glycine, N-(hydroxymethyl)-monosodium salt 

Registration Review Decision Document, located in the docket. 

Human Health Risk Assessment Status and Data Needs 

 The Agency did not perform a quantitative human health risk assessment at the time of 

the initial registration based on the low likelihood of exposure and the absence of adverse 

systemic effects in available toxicity studies. 

Dietary Assessment

 Dietary (food) exposure is not expected because the SHMG product cannot be used to 

preserve materials that may come in direct contact with food. 

 Due to the potential for dietary (drinking water) exposure from the material preservative 

use of SHMG, the Agency intends to determine the need for a drinking water assessment 

upon the submission and review of the environmental fate data anticipated to be needed 

for this registration review. 

 The Agency did not complete a dietary risk assessment for the initial registration of the 

only SHMG product. 

Tolerances and International Harmonization

 SHMG is not registered for use in products that may come in direct contact with food. No 

tolerance or tolerance exemption has been established in food as a result of use as a direct 

or indirect food additive, as an active ingredient, or as an inert ingredient. 

Occupational and Residential Assessment and Risk

 To determine the conditions under which residential and occupational exposure to the 

parent compound and/or formaldehyde are likely to occur from the use of SHMG as a 

preservative, the Agency anticipates requiring detailed use and other information, 

presented below, to clarify the conditions, rates, and magnitude of formaldehyde release 

from SHMG under various conditions and in various materials. 

 The Agency anticipates conducting residential risk assessments on adult applicator/user 

dermal and inhalation exposure and postapplication dermal and inhalation exposure to 

adults and children. 

 The Agency anticipates conducting occupational risk assessments on handler dermal and 

inhalation exposure during direct-pour activities, handler dermal and inhalation exposure 

to SHMG and inhalation risk to formaldehyde resulting from use or application of 

preserved water-based materials, and bystander inhalation risk to formaldehyde resulting 

from preservation of water-based materials. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

8 of 14 

 The Agency has not previously conducted quantitative occupational and residential risk 

assessments for SHMG. 

Aggregate and Cumulative Exposure and Risk

 In examining aggregate exposure, EPA takes into account the available and reliable 

information concerning exposures to residues in food and drinking water, and nonoccupational pesticide exposures. If the results of the environmental fate data indicate 

that a drinking water assessment is necessary, then the Agency anticipates the need to 

conduct an aggregate assessment for residential and dietary exposure to SHMG. In the 

absence of the environmental fate data, the Agency would assume that dietary exposure 

occurs and, therefore, would anticipate the need to perform an aggregate risk assessment. 

The Agency anticipates performing an aggregate assessment for all non-occupational 

sources of formaldehyde. 

 The Agency has not previously conducted an aggregate risk assessment for SHMG. 

 EPA does not have, at this time, available data to determine whether SHMG 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 SHMG does not 

have a common mechanism of toxicity with other substances when used as an 

antimicrobial as registered. 

Human Health Data Needs

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

for use in the registration review of SHMG. 

870.3250 -- 90-day dermal toxicity2

870.3465 -- 90-day inhalation toxicity (rat)2

870.3800 -- Reproduction and fertility effects (multigeneration or extended onegeneration)3

- rat 

875.1700 -- Product use information 

875.2700 -- Product use information 

875.2800 -- Description of human activity 

875.1100 -- Dermal outdoor exposure 

 

2

 If the environmental fate studies that are expected to be required demonstrate that SHMG rapidly and completely 

degrades to formaldehyde and glycine, registrants may request that EPA waive the requirement for Guideline 

870.3250 and Guideline 870.3465. 

3

 If the environmental fate studies that are expected to be required demonstrate that SHMG rapidly and completely 

degrades to formaldehyde and glycine such that residues of concern will not be expected to contaminate drinking 

water, registrants may request that EPA waive the requirement for Guideline 870.3800. If the registrant elects to 

perform an extended one-generation study, a protocol will need to be submitted for review and approval by the 

Agency prior to initiation. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

9 of 14 

875.1200 -- Dermal indoor exposure 

875.1300 -- Inhalation outdoor exposure 4

875.1400 -- Inhalation indoor exposure 4

875.1600 -- Application exposure data reporting and calculations 

875.2900 -- Data reporting and calculations 

 The Agency does not anticipate the need to require additional toxicity data on 

formaldehyde through the SHMG registration review. 

 Past SHMG risk assessments have relied in part on two human studies that involved 

intentional exposure to SHMG (both studies are combined in a single data volume, MRID 

43514301). In the course of registration review, EPA will reconsider these studies, as 

well as consider any other research involving intentional exposure of human subjects to 

SHMG brought to its attention. If EPA determines that the two previously-identified 

intentional exposure human studies (or any additional intentional exposure human studies 

brought to EPA’s attention) are sufficiently sound from a scientific perspective to warrant 

inclusion in future risk assessments, EPA will consider the ethical acceptability of the 

studies. Before reaching a final decision to rely on any such studies, EPA will ensure that 

all applicable regulatory requirements are met, including but not limited to the 

requirements for EPA ethics review and Human Studies Review Board review of certain 

research involving intentional exposure of human subjects. 

 For more information, please refer to Summary of Product Chemistry, Environmental 

Fate, and Ecotoxicity Data for the Glycine, N-(hydroxymethyl)-monosodium salt 

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 

the registration review of SHMG at this time. 

 For more information, please refer to Summary of Product Chemistry, Environmental 

Fate, and Ecotoxicity Data for the Glycine, N-(hydroxymethyl)-monosodium salt 

Registration Review Decision Document, located in the docket. 

 

 

4

 If the inhalation indoor (875.1400) and outdoor (875.1300) exposure data are required as anticipated, the DCI 

would provide that the registrant may elect to submit small chamber studies demonstrating formaldehyde air 

emission rates and any available Industrial Hygiene air sampling data (explained below). Based on the results of the 

small chamber studies, the Agency may determine that the inhalation indoor and outdoor exposure data expected to 

be required would no longer be necessary. The DCI would provide that, if the registrant elects to perform such 

small chamber studies, a protocol will need to be submitted for review and approval by the Agency prior to 

initiation. The Agency also anticipates the need to require that available Industrial Hygiene air sampling data from 

commercial facilities manufacturing, storing, or using large quantities of bulk or end-products made from preserved 

materials be submitted, especially for paper mills, facilities manufacturing preserved liquid materials, and other 

manufacturing facilities where SHMG is used as part of the inhalation indoor (875.1400) and outdoor (875.1300) 

exposure studies expected to be required. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

10 of 14 

Incidents:

Ecological: 

 No SHMG ecological incidents have been reported in the Agency’s Ecological Incident 

Information System (EIIS). 

Human Health: 

 No SHMG human poisoning incidents have been reported in the OPP incident database. 

Endangered Species 

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

determination for SHMG. The ecological risk assessment planned during registration review will 

allow the Agency to determine whether SHMG’s 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. A human health risk assessment identifying the most sensitive endpoints has 

not been conducted for the SHMG Case. As required by FFDCA section 408(p), SHMG is 

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. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

11 of 14 

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. SHMG is 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 SHMG. 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/. 

 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

12 of 14 

Timeline

EPA has created the following estimated timeline for the completion of the SHMG registration 

review: 

Activities Estimated Month/Year

Phase 1: Opening the docket 

Open Public Comment Period for Docket September 2011- 

Completed

Close Public Comment Period for Docket November 2011- 

Completed 

Phase 2: Case Development 

Develop Final Work Plan (FWP) February 2012- 

Completed 

Issue DCI March 2013 

Data Submission March 2015 

Open Public Comment Period for Preliminary Risk Assessments September 2016 

Close Public Comment Period for Preliminary Risk Assessments October 2016 

Phase 3: Registration Review Decision 

Open Public Comment Period for Proposed Reg. Review Decision March 2017 

Close Public Comment Period for Proposed Reg. Review Decision May 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 “Risk Assessments and Data 

Needs” section of this document. The Agency expects to issue the DCI in March 2013. Human 

health and ecological risk assessments will be conducted for all uses of SHMG. 

 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

13 of 14 

Summary of Anticipated Data Requirements – SHMG 

The table below summarizes anticipated data needs for the SHMG Case in this document (Final 

Work Plan), Summary of Product Chemistry, Environmental Fate, and Ecotoxicity Data for the 

Glycine, N-(hydroxymethyl)-monosodium salt Registration Review Decision Document., and 

Glycine, N-(hydroxymethyl)-, monosodium salt. Human Health Scoping Document for the 

Registration Review.

Guideline 

Number Anticipated Data Requirement Test Material 

Estimated Timeframe 

(Measured in months from 

DCI Receipt) 

870.3250 90-day dermal toxicity5 TGAI 24 

870.3800 90-day inhalation toxicity (rat)5 TGAI 24 

870.3800 Reproduction and fertility effects 

(multigeneration) - rat6 TGAI 24 

875.1700 Product use information TGAI 12 

875.2700 Product use information TGAI 12 

875.2800 Description of human activity TGAI 12 

875.1100 Dermal outdoor exposure TGAI 24 

875.1200 Dermal indoor exposure TGAI 24 

875.1300 Inhalation outdoor exposure7 TGAI 24 

875.1400 Inhalation indoor exposure7 TGAI 24 

 

5

 If the environmental fate studies that are expected to be required demonstrate that SHMG rapidly and completely 

degrades to formaldehyde and glycine, registrants may request that EPA waive the requirement for Guideline 

870.3250 and Guideline 870.3465. 

6

 If the environmental fate studies that are expected to be required demonstrate that SHMG rapidly and completely 

degrades to formaldehyde and glycine such that residues of concern will not be expected to contaminate drinking 

water, registrants may request that EPA waive the requirement for Guideline 870.3800. If the registrant elects to 

perform an extended one-generation study, a protocol will need to be submitted for review and approval by the 

Agency prior to initiation. 

7

 If the inhalation indoor (875.1400) and outdoor (875.1300) exposure data are required as anticipated, the DCI 

would provide that the registrant may elect to submit small chamber studies demonstrating formaldehyde air 

emission rates and any available Industrial Hygiene air sampling data (explained below). Based on the results of the 

small chamber studies, the Agency may determine that the inhalation indoor and outdoor exposure data expected to 

be required would no longer be necessary. The DCI would provide that, if the registrant elects to perform such 

small chamber studies, a protocol will need to be submitted for review and approval by the Agency prior to 

initiation. The Agency also anticipates the need to require that available Industrial Hygiene air sampling data from 

commercial facilities manufacturing, storing, or using large quantities of bulk or end-products made from preserved 

materials be submitted, especially for paper mills, facilities manufacturing preserved liquid materials, and other 

manufacturing facilities where SHMG is used as part of the inhalation indoor (875.1400) and outdoor (875.1300) 

exposure studies expected to be required. 
Docket Number: EPA-HQ-OPP-2011-0615 

www.regulations.gov

14 of 14 

875.1600 

Application exposure data reporting and 

calculations TGAI 24 

875.2900 Data reporting and calculations TGAI 24 

850.5400 

Algal Toxicity Tier II using freshwater green 

alga, 

Selenastrum capricornutum

TGAI 

12 

835.1110 Activated Sludge Sorption TGAI 12 

835.2120 Hydrolysis TGAI 12 

835.2240 Photodegradation in water TGAI 12 

850.6800 

Modified activated sludge, respiration 

inhibition test 8 TGAI 12 

835.3110 Ready Biodegradability8 TGAI 12 

835.3220 Porous Pot Test8 TGAI 12 

835.3240 

Simulation Test – Aerobic Sewage 

Treatment: A. Activated Sludge Units8 TGAI 12 

835.3280 

Simulation Tests to Assess the 

Biodegradability of Chemicals Discharged to 

Wastewater8

TGAI 

12 

 

8

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.