Program for the Identification and Replacement of Endocrine Disrupting Chemicals
Douglas Young
US EPA
National Risk Management Research Laboratory
Cincinnati, OH

Project Outline
.. Still in planning phase
.. Develop a unique method for identifying potential EDC (external)
.. Develop a program to aid in suggesting replacements for EDC (internal)
.. If possible, combine into one software program

Identifying Potential EDC
.. Use a QSAR type approach to quickly identify potential EDC (external)
.. No duplication of concurrent efforts (such as COREPA and CoMFA)
.. Use as another validation tool for concurrent efforts
.. There is a Request for Proposals (RFP) to establish a collaborative agreement currently underway

Identifying Potential EDC cont’d
.. Collaborator to be largely responsible for this portion of the project (Thesis or Dissertation work)
.. We can help collect data needed to fill library 

Replacement of Potential EDC
.. Develop software that will aid in suggesting replacements for known or potential EDC (internal)
.. Off shoot of the PARIS II Project (Program for Assisting the Replacement of Industrial 
Solvents)

PARIS II
.. Suggests possible replacements for currently used solvents or solvent mixtures
.. Uses the DIPPR (Design Institute for Physical Property Relationships) and UNIFAC to estimate 
20 physical and chemical properties of the solvent(s) to be replaced
.. Tries to find best match within database of over 1500 chemicals

PARIS II cont’d
.. If it can’t find a single replacement, it will allow the user to design a mixture
- The user chooses the primary component and then the program will find the chemical that would form the best mixture
.. If it can’t find two component replacement, it will allow the user to add a 3rdchemical to the mixture
.. Ad infinitum

EDC version of PARIS II
.. The framework and coding are established
.. Select key physical and chemical properties to satisfy the requirements for the specific EDC 
application
.. Might not work with compounds that are designed to be pesticides & herbicides

Example
.. Di(2-ethylhexyl)phthalate (DEHP) 
- Used as a plasticizer for PVC medical tubing
- FDA has released a safety assessment on DEHP 
- Found that infants in certain circumstances may be exposed to unacceptable levels of DEHP
.. Replacement outline
- Describe qualities that are required for a plasticizer
- Search the database for possible replacements

Example Cont’d
.. Replacement Outline
- Describe qualities that are required for a plasticizer
. Plasticization Efficiency
. Solubility
. Tensile strength
. Toxicity
. Vapor Pressure
. Viscosity
.. Match properties using components in database that have less potential for ED activity
.. Suggest a replacement or replacement mixture

Final Product
.. A software program that will have a methodology to identify potential EDC and then will allow the user to design possible replacement chemicals (non potential EDC) based on desired properties
.. Will be used as another validation tool to compliment the concurrent research projects

Timeline
.. External
- Determine collaborator during Winter of 2002
- Project will begin Spring/Summer of 2002
- Expected to last 3 years
.. Internal 
- Post-doc already in place
- Project began January of 2002
- Expected to last 3 years