ADL Polymer Migration Estimation Model (AMEM)
What Does AMEM do?
The ADL Polymer Migration Estimation Model (AMEM) estimates the fraction of a chemical additive that migrates from polymeric materials to air, water, and solids. There are "default" coefficients for six different polymers: silicone rubber, natural rubber, LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), polystyrene, and unplasiticized PVC (Polyvinylchloride).
The model assumes:
- The chemical is homogeneously distributed throughout the polymer and is not initially present in the phase external to the polymer,
- Migration of the chemical is not affected by the migration of any other chemical or by the penetration into the polymer of any component of the external phase,
- The migration is isothermal,
- and Fick's law of diffusion and convective mass transfer theory applies.
How Does AMEM Work?
AMEM is a DOS-based software product developed in 1989 that uses a family of mathematical equations that address simple and complex scenarios for chemical migration through a specific polymer. The more complex equations require more input data. Using the model, you may:
- Develop migration estimates,
- Consider the effect of chemical partitioning between the polymer and the external phase,and
- Consider the effect of mass transfer resistances in the external phase.
In all cases the model estimates the fraction migrated (i.e., the fraction of the chemical initially present in the polymer that migrates) after a specified duration. This model only provides one parameter needed to estimate exposure. The user must then use other equations and/or models to estimate exposure.
What Do I Need to Use AMEM?
Polymer category (i.e., Silicone Rubber, Natural Rubber, LDPE, HDPE, Polystyrene, or unplasiticized PVC) or diffusion coefficient of the polymer.
- Molecular weight of additive.
- Total polymer sheet thickness (cm) External phase (i.e., air, water, or solid)
- One or two sided migration Time frame of interest
What Type of Computer System Do I Need?
- Processor - IBM-compatible computer with a Pentium microprocessor (minimum speed: 33 MHZ)
- Memory - 640K
- Hard disk space - 2 MB
- Operating System - AMEM is a DOS-based program, however, in can be run in a Windows environment by using key strokes not a mouse.
What is AMEM's Status and Availability?
AMEM is available as a DOS program . The model has been peer reviewed by experts outside EPA. AMEM was developed by Arthur D. Little Inc. under a subcontract with Versar, Inc. for the EPA Office of Pollution Prevention and Toxics, Economics, Exposure, and Technology Division, Exposure Assessment Branch (EAB).
The AMEM model can be downloaded and installed using download AMEM.
The user's guide and background document is available as a pdf file.
PLEASE NOTE: the documentation manual linked
from this page is in Adobe's Portable Document Format (PDF). To view
or print them you will need to have the Adobe Acrobat Reader program
installed on your computer. The Reader can be downloaded and used with
no charge; for more information at EPA about PDF files.
Who Can I Call for More Information?
For more information about the model, contact:
U.S.Environmental Protection Agency
Office of Pollution Prevention and Toxics
1200 Pennsylvania Avenue N.W.
(Mail Code 7406M)
Washington, DC 20460
E-mail: Christina Cinalli