Benchmark Dose Software (BMDS)


EPA has announced the latest update to the Benchmark Dose Software (BMDS) tool which is used to facilitate the application of benchmark dose (BMD) methods to EPA hazardous pollutant risk assessments. This latest version (1.4.1b) contains seventeen (17) different models that are appropriate for the analysis of dichotomous (quantal) data (Gamma, Logistic, Log-Logistic, Multistage, Probit, Log-Probit, Quantal-Linear, Quantal-Quadratic, Weibull and Multistage-Cancer), continuous data (Linear, Polynomial, Power, and Hill) and nested developmental toxicology data (NLogistic, NCTR, and Rai & Van Ryzin).

Use of BMD methods involve fitting mathematical models to dose-response data and using the different results to select a BMD that is associated with a predetermined benchmark response (BMR), such as a 10% increase in the incidence of a particular lesion or a 10% decrease in body weight gain. BMDS facilitates these operations by providing simple data-management tools and an easy-to-use interface to run multiple models on the same dose-response data set.

Results from all models include a reiteration of the model formula and model run options chosen by the user, goodness-of-fit information, the BMD, and the estimate of the lower-bound confidence limit on the BMD (BMDL). Model results are presented in textual and graphical output files which can be printed or saved and incorporated into other documents.

The use of BMDS gnerally involves four basic steps:

  • Step 1: Create a data set using BMDS spreadsheet facility,or import a data set from text, Excel or Lotus spreadsheet file.

  • Step 2: Select appropriate model based on type of data being evaluated.
  • Step 3: Specify run options and parameters for selected model.
  • Step 4: Run Model and view textual and graphical results.

Complete documentation for use of BMDS is provided within the program's online help facility. Hard copy documentation can be downloaded via the link provided below.

Prior to the 1990's, RfDs and RfCs had been determined from no-observed-adverse-effect levels (NOAELs), which represent the highest experimental dose for which no statistically significant adverse health effects were reported or, in the absence of a NOAEL, the lowest-observed-adverse-effect levels (LOAEL). In 1995, EPA's Risk Assessment Forum published guidance on the benchmark dose (BMD) approach in the assessment of noncancer health risk (U.S. EPA, 1995) which listed several advantages of the BMD approach over use of NOAELs and LOAELs. In 1995, EPA's National Center for Environmental Assessment (NCEA) initiated a project to develop benchmark dose software to assist Agency risk assessors in deriving benchmark dose values for use in Agency risk assessments.


While EPA BMD methods guidance has not been finalized at this time, every attempt has been made to make his software consistent with the most recent working draft guidance and other Agency risk assessment guidelines, including the latest Guidelines for Carcinogen Risk Assessment (EPA 2005). A link to the latest draft of the Benchmark Dose Technical Guidance Document (October, 2000) is provided below. It is currently undergoing an external, EPA Risk Assessment Forum (RAF) review.

Additionally, EPA plans to continually improve and expand the BMDS system. Additions under consideration for future versions of BMDS include a finalized EPA cancer model, additional dichotomous models (e.g., a dichotomous Hill and background dose models), additional exponential continuous models, supplements to the continuous models (e.g., with Hybrid model capability), additional statistics for evaluating fit at low doses and comparing models, a time-to-tumor model, a model for evaluating time-dependent, continuously measured (e.g., neurotoxicity functional) effects of a single exposure and additional tools/models for the analysis of human data.

Futher information can be obtained by e-mailing or writing to Dr. Jeff Gift, EPA (MD-B-243-01), Research Triangle Park, NC 27711.


1995EPA Risk Assessment Forum publishes initial guidelines on the use of the BMD approach in the assessment of noncancer health risk.
1995EPA National Center for Environmental Assessment (NCEA) in RTP, NC begins the development of EPA's benchmark dose software (BMDS).
1999Public and External Review of BMDS version 1.1b
2000Public release of BMDS version 1.2 via the EPA/NCEA website.
2000EPA/NCEA distributes Draft Benchmark Dose Technical Guidance Document.
2001Release of BMDS version 1.3 via the EPA/NCEA website.
2002Release of BMDS version 1.3.1 via the EPA/NCEA website.
2003Release of BMDS version 1.3.2 via the EPA/NCEA website.
2006Release of beta version of BMDS 1.4.0
Feb 2007Release of BMDS version 1.4.1 via the EPA/NCEA website.

Additional Information

Use this web page as your most up-to-date source of information pertaining to the BMDS. We would also like to be able to notify you when new releases or important information becomes available. Thus, while we suggest that all users and reviewers of the BMDS register with us before downloading the software (distributed in the form of a self-extracting zip file), registration is not required to download the software. We also offer the C source code files for the individual models used in the BMDS system to reviewers/programmers that might be interested in performing an in-depth analysis of the model algorithms and features. We welcome, in fact encourage, your comments on the BMDS software and the model source code files. Please provide comments, recommendations, suggested revisions, or corrections, to Written comments can be addressed to Dr. Jeff Gift, EPA (MD-52), Research Triangle Park, NC 27711.