An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Benchmark Dose Tools

Benchmark Dose Software (BMDS) - Version 3


The purpose of BMDS is to estimate the dose or exposure of a chemical or chemical mixture associated with a given response level, to facilitate hazardous pollutant risk assessments. Its intended audience is EPA risk assessors.

BMDS 3 is a major re-design of BMDS, containing substantial model code and interface enhancements reflecting nearly two decades of experience and feedback on the needs of risk assessors with respect to benchmark dose modeling

The BMDS 3 application and software components are the result of a collaborative effort between EPA and the National Institute for Occupational Safety and Health (NIOSH). The goal of the collaboration was to meet current dose-response needs of chemical risk assessors and introduce state-of-the-science dose-response methods such as Bayesian analysis and model averaging.

Subscribe to the BMDS newsletter to stay informed on BMDS updates and training opportunities.

On this page:

New Interface Implemented via Microsoft Excel

BMDS 3 moves away from its former application-based platform to one implemented within Microsoft Excel 2016, with modeling computations performed in custom-programmed DLLs.

This implementation leverages user familiarity with Excel spreadsheets to streamline data input and analysis:
  • Fast analysis of multiple datasets and options
  • Enables users to see and specify modeling options in a single worksheet
  • Flexible documentation and report generation
  • Facilitates use of EPA methods and guidance
  • Includes auto-selection features for identifying the “best” results in accordance with EPA recommendations or user-defined logic
  • Documents all inputs and outputs in a single results workbook for each dataset modeled
  • Provides flexible print options for displaying results in Microsoft Word tables formatted in a manner suitable for presentation in a risk assessment
  • Backwards compatible with prior BMDS versions

The BMDS 3 "application" can be thought of as a pair of Excel workbooks: an Analysis Workbook and a Results workbook. 

Analysis Workbook

Datasets, modeling, and reporting options for an analysis are entered in the BMDS 3 Analysis Workbook. Users can specify modeling options from intuitive forms and picklists. All calculations are performed within the Analysis Workbook.

The Analysis Workbook is designed to facilitate performing and tracking dose-response analyses of the following types of datasets:
  • Multiple dichotomous
  • Combined tumor
  • Nested dichotomous
  • Continuous response
Depending on the needs of the risk assessment, users can focus a BMDS 3 analysis on datasets associated by:
  • study (e.g., for chemicals with a large database of studies)
  • chemical (e.g., for chemicals that are not well-studied)
  • health outcome (e.g., for chemicals with health outcomes that have been assessed in multiple studies and/or by multiple response measures)

Results Workbook

All datasets, modeling, and reporting options entered in the BMDS 3 Analysis Workbook can be saved and retrieved at any time prior to or after modeling.

When modeling is performed, all model results are recorded in a separate Results Workbook for each dataset analyzed.

All of the options used in the analysis are saved in each Results Workbook so they can be re-initiated. So if you want to, for example, rerun the analysis with different options, you can use the Results Workbook to re-initiate the analysis in the Analysis Workbook.

Top of Page

New State-of-the-Science Modeling Methods

NOTE: At this time, EPA does not offer technical guidance on Bayesian modeling or Bayesian model averaging.

  • Bayesian versions of all traditional frequentist dichotomous models
  • Bayesian model averaging using all or weighted dichotomous models
  • Hybrid approach added to all continuous models
  • Lognormal response distribution added for all continuous models
  • ​All existing models have been re-coded to facilitate their maintenance and improve their performance in terms of stability, accuracy, reliability, and speed.

Top of Page

Models Not Included in BMDS 3

BMDS 3 contains all the models and features that were available in BMDS 2.7 and BMDS Wizard 1.11 except for:

These models are not maintained or supported by EPA at this time, but can be accessed in  BMDS 2.7.  BMDS 2.7 is no longer maintained or supported, but BMDS 2.7 materials are available for historic or research purposes.

Top of Page