# Presentation: 122110

## ChemSTEER Overview

**Chemical Screening Tool for Exposures and Environmental Releases**

**Office of Pollution Prevention & Toxics**
**Chemical Engineering Branch**
**Washington, DC**
**May 2004**
**Beta Version**

## What does this PC-based software do?

- Estimates *workplace exposures and releases* to a chemical:
- in the absence of monitoring data
- estimates are screening-level
- uses EPA methods and models

## How can it be used?

- Currently used by EPA for:
**Workplace release and exposure estimation for new chemicals submitted for PMN review under TSCA Section 5***
**Sustainable Futures Program submissions**
- Other potential uses:
**Fill data gaps in HPV exposure assessments**
**As an initial *****Green Engineering***** design tool**
*** Note: Of the new chemicals regulated under Section 5, a significant fraction are regulated based on estimated workplace release and exposure**

## Exposure Information Flow in New Chemicals Risk Screening

## How can it be used in the P2 Framework?

- The *MPBPVP Model* may be used to estimate a chemical’s _vapor pressure_ and the *WSKOW Model* may be used to estimate a chemical’s _water solubility_.  Each of these parameters are used in some of the ChemSTEER models.

- The ChemSTEER _environmental release_ estimates may be used as inputs to the *E-FAST Model*.

- Vapor pressure

## How does it work?

- You “build” your assessment by entering some key inputs:
- Data on the*** chemical*** to be assessed, including:
- Production volume (or assessed volume) (kilograms per year)
- Physical/ chemical properties (known or estimated)
- Select at least one ***operation*** (i.e., workplace); options include:
- Pre-defined industry-specific / use-specific operation
- User-defined operation

## How does it work? (continued)

- You “build” your assessment by entering some key inputs:
- Select at least one ***release source/ exposure activity*** within each operation
- Each source/ activity is associated with ***default models*** for calculating releases and worker inhalation and dermal exposures
- Enter ***mass balance*** and ***container-related*** data
- Review ***models*** and ***model input*** data

## Entering General Information

- This tab allows you to view and/or enter general information related to the ChemSTEER assessment:
- Assessment name
- Date of completion
- Assessor information
- Contact information for the assessment
- Report(s) summarizing information received from a contact
- General comments related to the assessment

## Entering Chemical Information

- This tab allows you to view and/or enter information related to the chemical to be assessed.
- The ***Production Volume (PV)*** (amount of chemical to be assessed) is an important input parameter –  it is used in many mass balance, container-related, release, and exposure calculations.

- The physical-chemical property parameters (e.g., vapor pressure, molecular weight) _*may be needed*_ by some release and/ or exposure models.

## Selecting Operations to be Assessed

- An ***Operation*** is a workplace or set of “homogeneous” workplaces with essentially the same processes, equipment, chemical throughputs, procedures, and worker populations.
- Each of the workplaces within an operation are assumed to have the _*same*_ releases of and worker exposures to the chemical being assessed.
- One or more operations, in which the chemical is manufactured, processed, and/or used, are selected to be included in the chemical assessment.

- Some examples of operations are:
- Manufacture
- Formulation of paint (User-defined Processing)
- Formulation of adhesives
- Automobile spray coating

## Setting the Operation Relationships

- The relationships between multiple operations may be defined in ChemSTEER.  A straight-series lifecycle of more than one operation (shown below) is the default relationship configuration.

- ChemSTEER allows you to re-define the operation relationships.  For example, the above series can be rearranged into a more complex, branched lifecycle of operations as follows:

## Selecting Sources/Activities

- For each operation,

- At least one release source/ exposure activity must be selected

- A ***source/activity*** is a _*source of chemical release*_ to the environment and/or an _*activity that results in a worker exposure*_ to the chemical within an operation.

_***This selection is critical***_, as it will determine which default release/exposure models are used for the calculations.

## Entering Operation Mass Balance Parameters

***Mass balance parameters*** are the set of input values that define each operation and associated chemical throughputs.
- ChemSTEER allows you to input the information that is known and will calculate remaining unknown parameters based upon a mass balance of the chemical around the operation.

- Consult the ***Help System*** to learn more about the logic by which ChemSTEER makes mass balance calculations.

## Entering Operation Container Parameters

***Container parameters*** are the set of input values that define the number of containers that are filled with the chemical, emptied, and/or cleaned during each operation.
- As with the mass balance parameters, ChemSTEER allows you to enter information about the containers that is known and will calculate remaining unknown parameters based upon a mass balance.

- Consult the ***Help System*** to learn more about the logic by which ChemSTEER makes container-related calculations.

## Release Calculations

- At least one default release model is associated with each source/ activity within each operation.
- The release models are used for calculating the chemical releases to the environment that occur during the activity.

- In the screen shown above, the default model for calculating releases from the ‘Loading Liquid Product into Small Containers’ source within the ‘Formulation of Paint’ operation is the *EPA/OAQPS AP-42 Loading Model*.

## Release Calculations (continued)

- Each release model contains the input parameter values that are necessary to perform the calculation by default.
- Some values are obtained via previous input or calculations (e.g., mass balance or container parameters) or are pre-programmed defaults.

- You may modify any of the model input parameters (provided they are not determined through calculations performed in another input screen).

## Release Calculation Results

- Environmental release results include:
- Media of release (i.e., air, water, incineration, and/or landfill)
- Characterization (e.g., typical, worst case, average, high end)
- Number of sites releasing the chemical
- Days of release (days per site-year)
- Daily release rate (kg chemical per site-day)
- Annual release rate (kg chemical per year, all sites combined)

## Worker Exposure Calculations

- The exposure models are used for calculating the worker *inhalation* and *dermal* exposures to the chemical during the activity.
- As with the release sources, each activity resulting in a worker exposure will have associated default inhalation and/or dermal exposure model(s).

- In the screen shown above, the default inhalation model for worker exposure to the chemical vapor during the ‘Loading Liquid Product into Small Containers' activity within the ‘Formulation of Paint’ operation is the *EPA/OPPT Mass Balance Model*.

## Worker Exposure Calculations (continued)

- Each exposure model contains the input parameter values that are necessary to perform the calculation by default.
- Some values are obtained via previous input or calculations (e.g., container parameters, associated release model calculations) or are pre-programmed defaults.

- You may modify any of the model input parameters (provided they are not determined through calculations performed in another input screen).

## Exposure Calculation Results

- Worker exposure results include:
- Route of exposure (i.e., inhalation or dermal)
- Characterization (e.g., typical worst case, average, high end)
- Total number of workers exposed
- Days per year of exposure
- Potential dose rate (mg per day)
- Lifetime average daily dose (mg per kg-day)
- Average daily dose (mg per kg-day)
- Acute potential dose (mg per kg-day)

## Features – User-Friendly Design

- ChemSTEER is designed such that ***new, as well as experienced*** users can use the software to perform screening-level estimates:
- ChemSTEER steps you through the process of creating an assessment scenario
- Every screen contains instructions of what inputs you must enter to proceed
- All default models are designed to be transparent (i.e., all assumptions and values are documented)

- ChemSTEER contains an ***extensive Help System*** that documents the bases for every model and every default value.  The Help System also contains a library of background documentation.

## Features – Creating Summary Reports; Saving Assessments

- Assessments may be saved as individual records in a database file containing multiple assessments.
- Maintaining a database of multiple assessments allows you greater flexibility in organizing collections of assessments.

- You may view and print an EPA-formatted summary report (shown at left).  You may also save the report to a destination on your hard drive or external disk - as a text* (.txt) file or various other types of file formats (*only the _text_ file format has been thoroughly tested).

## What is its status?

- May 2004 Beta version
- Contains primary “broadly applicable” models (e.g., drum loading release and exposure, equipment cleaning, dermal contact, etc.) and industry-specific models
- 17 release models
- 17 exposure models
- Contains 4 industry-specific operations
- two Automotive Spray Painting operations
- one Adhesives Formulation operation
- one Water-Cooling Tower Additive Use operation

## Summary of New Features

- Since the last public release of ChemSTEER in July 2003, the following new functions have been implemented in this version:
- Capability of opening/modifying older assessments with new versions of the software
- Automatic transfer of contact information to multiple Contact Reports
- Operation NAICS code search function
- New Recirculating Water-Cooling Tower Additive Use industry-specific operation
- Automatic transfer of site information from one operation to another

## Summary of New Features

- Container unloading & cleaning sources/activities are automatically added to operations as a pair (one is automatically added when the other is added by the user)
- Model status messages on the Releases and Exposures tabs
- Ability to run two sets of inputs (or conditions) in a single model to calculate two release or exposure estimates
- Releases are no longer combined in ChemSTEER or in the IRER
- Each of these new features is described in the *ChemSTEER Self-Guided Tutorial*, which can be viewed/downloaded from EPA’s web site (see next slide).

## For More Information

- Contact information and the most recent version of ChemSTEER are available from the following EPA Internet site:
*http://www.epa.gov/oppt/exposure/*
- This web site also contains links to the *ChemSTEER Self-Guided Tutorial*, as well as to other exposure-related information and models available from EPA.