By instituting a number of precautions (e.g. personal monitoring, enhanced ventilation) dentists have been able to reduce the risk of mercury escaping into the environment. While these precautions are significant there are still numerous instances of mercury emissions above approved regulations. These Hg emissions compromise health of dental personnel. In Phase I Compact Membrane Systems (CMS) demonstrated the feasibility of a small, safe, low cost system that can be placed within the dental office or within the air duct system to actively remove elemental mercury and convert it to mercury sulfide (HgS). (Removal of metallic mercury is actually more difficult than ionic mercury). CMS has identified low cost commercial routes to collect the HgS and by sending in bulk to Hg retorters the Hg can be recovered. The overall business model provides an annual service to the dentist for less than $500 and minimizes the dentist's exposure or liability. Phase I demonstrated that the CMS system could both easily remove the spiked levels of mercury that was in the air and that this could be done when using the proper system with minimal concern for system fouling. By using proper chemical systems we were able to successfully remove elemental Hg under poor mixing conditions with no fouling seen over a 14-day test period. This strongly suggests that in Phase II using enhanced/optimized liquid side mixing that long term fouling should not be an issue. Phase II will optimize/enhance the core technology and build prototype for field demonstration. Numerous local dental offices have committed to participate in field evaluation and leaders in the dental mercury emissions field at a national university have agreed to participate in both field testing and program activity. System optimization will include enhancing long term stability, minimizing fouling potential, basic data for low cost service while maintaining high mercury vapor removal capability. Systems will be designed for upwards of 30 grams of mercury removal per year. Compact Membrane Systems (CMS) has established strong industrial partnerships. These partnerships will enhance CMS's capability to successfully complete the Phase II and subsequent commercialization. ? ? ?