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• SEHSC is committed to science-based risk assessment and responsible 

environmental stewardship

• SEHSC Proposal based upon sound-science with substantial justification

o Number of sites is not primary driver for proposal

o Proposal supported by accepted environmental risk assessment methods

o Detailed member facility release assessments

o Development of Conceptual Site Models

o Environmental consultant justification for monitoring program

• Agency sampling & analysis plan may have omitted critical elements

• Power analysis to determine adequate sample numbers

• Essential field and laboratory quality control samples

• Control for loss and contamination

• Stability and sample integrity

• Validation and use of the appropriate analytical methods

• SEHSC is committed to working with the agency to address information “gaps”. 

SEHSC D4/D5 Monitoring Proposal – Discussion Elements
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• Methodologies for assessing risk should be 

consistent for new and existing chemicals.

o Greater transparency would foster cooperation 

and be a greater incentive for product innovation. 

SEHSC D4/D5 Monitoring Proposal – Discussion Elements
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SEHSC Municipal Wastewater Treatment Plant (POTW) Monitoring 

Proposal Overview

5 POTW Sites

 Site #1 – Activated sludge, 

high population, low 

dilution, capped (for air)

 Site #2 – Activated sludge, 

high population, low 

dilution

 Site #3 – Activated sludge, 

high population, low 

dilution

 Site #4 – Lagoon, 

Activated sludge, high 

population, low dilution

 Site #5 – Lagoon, high 

population, low dilution

Monitoring Parameters

 Influent, Effluent

 Surface Water

 Bio-solids

 Sediment

 Fish

 Benthic Species

 Air (Site #1)

 2 Monitoring Events
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SEHSC Manufacturer, Processor, Formulator (MPF) Monitoring 

Proposal Overview

Monitoring Parameters

 Effluent

 Surface Water

 Sediment

 Fish

 Benthic Species

 2 Monitoring Events

Dow Corning

Carrollton, KY

D4/D5 M & F

Wacker

Adrian, MI

D4/D5 P & F

Momentive 

Waterford, NY

D4/D5 M, P, F

Momentive 

Sistersville, WV

D4/D5 P
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 EPA’s proposal presumes that D4 and D5 require risk management without having conducted a 

risk assessment first. To the contrary, an appropriate risk assessment should include the 

following:

o Risk-based decision-making is a two tier process where the potential environmental risks 

associated with a material are systematically evaluated through a risk assessment followed 

by a separate process for risk management, if necessary.

o Risk management should be considered only after risk is identified. The nature and 

magnitude of the risk should inform the risk management activities, including selection of 

the most practical risk management instrument. 

o A practically designed and efficient monitoring proposal facilitates a determination first of 

whether risk management is needed before implementing the much more significant effort 

of determining how to manage risk. 

 The Agency has not provided a scientific justification for conducting a national exposure 

assessment prior to a screening level risk assessment.

o Conducting a screening level risk assessment is consistent with EPA risk assessment 

guidance and will better focus resources. 

o Monitoring 5 POTWs and 4 direct discharge sites will provide a sufficient dataset for 

conducting a worst-case environmental assessment of D4 and D5.

o If no risk is identified with a worst-case assessment additional data collection is not 

warranted.

D4 / D5 ECA Development Points
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D4 / D5 ECA Development Points (cont’d)

 Data from SEHSC member indirect discharge facilities will not provide 

relevant information on environmental compartment exposures.

o POTW monitoring provides relevant data for understanding environmental 

exposure in support of a screening level risk assessment.

 The full value of available monitoring data has not been considered for 

informing the development of a D4/D5 monitoring program.

o Reasonable justification has not been provided to dismiss the utility of non-US 

monitoring data for informing a US assessment of potential risk.

o While the Canadian monitoring study does include data for lagoons, the study is 

not exclusively focused on lagoons.

o Industry’s on-going voluntary international monitoring program, which includes 

sites in the US, provides additional data that inform the overall assessment of 

environmental exposure and potential risk from D4 and D5. Results will be 

available to the EPA and other regulatory bodies around the world.
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D4 and D5 Risk Assessment 

• There has been extensive research on the environmental fate and 

effects of D4 in recent years. 

• The environmental fate of a chemical compound is determined by 

its basic physicochemical characteristics and their relationship to 

other physicochemical characteristics of the environment:

 binding to organic carbon, lipid content of organisms, and 

concentrations of inorganic ions, such as sulfide and calcium. 

 This has allowed the EPA and the “EPA’s” of other countries to utilize 

toxicity threshold data from around the world to develop their own 

water and sediment quality criteria. 

• There is no scientific reason why D4 and D5 should be treated otherwise. 

• These two chemicals are not toxic at concentrations below their solubility, 

which means they are not toxic at the maximum concentrations that 

could exist in the environment. 

• The “worst case scenario” for environmental risk associated with D4 and 

D5 is the presence of these chemicals at concentrations near their 

solubility and at these concentrations there will be no environmental risk. 
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D4 and D5 Risk Assessment 

• D4 and D5 behave differently than other compounds that are similar in 

molecular weight and size. 

 These characteristics result in unique distributions in the environment and 

explain their lack of toxicity and risk. 

 These chemicals readily partition into air, no matter where they are discharged 

into the environment. In the air compartment they readily degrade. 

• Given the 30+ years of use of these chemicals it can be assumed they 

are at a relative steady state in the environment. 

 Even if they were not, they cannot accumulate at concentration in aquatic 

systems that are above their solubility. 

 In addition, degradation of these compounds in aquatic ecosystems and their 

metabolism within organisms further prevents concentrations that would 

present a risk. 

 Their strong partitioning to organic carbon is reflected by their sometimes 

elevated concentrations in sediments which are the compartment of greatest 

exposures to benthic organisms. 

• Nevertheless, these exposures would not exist above D4 and D5 solubility limits and 

are not toxic.