ICC's Ad Hoc Committee for Hydrogen Gas
Final "In-person" Meeting Summary

Patrick Serfass, National Hydrogen Association
Darren Meyers, ICC (contributing)


In preparation for the 2004/05 Final Action Hearings to the International Codes, the International Code Council's (ICC's) Ad Hoc Committee for Hydrogen Gas (AHC) held its final in-person meeting June 1st and 2nd, 2005 at ICC's Chicago District Office in Country Club Hills, Illinois.

Committee members reviewed material for public comments that were recently submitted on behalf of the AHC for the 2004/05 Final Action Hearings to take place. Those hearings will take place from September 25th through October 2nd, 2005 at the COBO Conference and Exhibition Center in Detroit, Michigan.

Meeting Highlights
At the meeting, much discussion focused on data that might be used to update the separation distance requirement. In particular two reports were given: one on the Canadian Transportation Fuel Cell Alliance's (CTFCA) Hydrogen Clearance Distances final report; and another from Sandia National Laboratories on continuing investigations of large-scale hydrogen releases.

On behalf of the CTFCA, Andrei Tchouvelev of A.V. Tchouvelev & Associates led discussion on the CTFCA report. Discussion of the report prompted some spirited debate primarily on two topics: whether there should be two kinds of vent stack clearance distances; and grid sensitivity of the model. The vent stack discussion suggested that clearances might need to differentiate between: 1) distances from personnel at the human height level (based on thermal effects); and 2) distances from ignition sources, air intakes and other operable openings in buildings (based on flammable gas concentration). The AHC supported the philosophy of the approach to differentiate between the two distance classifications and suggested consideration by the hydrogen industry in future code change submittals. With regard to the grid sensitivity discussion, the AHC questioned whether an adequate number of computations (nodes) were used in the model. It was determined that the grid sensitivity of the model could be improved, but overall the information presented in the report would be useful when used in conjunction with other separation distance studies.

Bill Houf and Chris Moen of Sandia National Laboratory reported the latest data from large-scale Sandia/Southwest Research Institute hydrogen jet flame tests that lower the radiation hazard distances for personnel at the human height level (based on thermal effects). An uncertainty analysis for the jet flame radiation and unignited jet models was also presented to the AHC as previously requested.

Some discussion ensued on how risk assessments should be used in the development of vehicular-based fuel provisions in codes and standards. The AHC was focused on using this information to facilitate the transition of hydrogen from a widely used industrial gas, to a consumer-handled fuel. The AHC agreed that a uniform set of risk metrics needs to be established across all vehicular fuels (e.g., Petroleum, Ethanol, CNG, LPG, LNG, H2G, LH2), specifically gasified vehicular fuels. That way, a benchmark standard of risk accounting can be applied equitably across the national vehicle refueling infrastructure. Such an approach might allow reverse-engineering of the system design and components so that gasified fuels can be established in society with a minimum standard of acceptable risk.

Since nearly 80% of the AHC's proposed changes affecting hydrogen received favorable recommendations, the AHC elected not to pursue public comments on the few remaining items receiving recommendations for disapproval, including F189-04/05-Canopy storage, automatic v. manual discharge; F237-04/05-Deleting metal hydride storage without replacement; and M38-04/05-Deleting the natural ventilation exception. However, several industry groups expressed their intent to champion public comments to these proposals.

In closing, the AHC charged the committee Secretariat with summarizing key accomplishments, lessons learned and next steps accumulated by the AHC since its inception in August 2000 in a report to the ICC Board. The AHC will reconvene occasionally via teleconference and email over the coming months to review the Final Action agenda and prepare for testimony on the hearing room floor at the 2005 ICC Annual Conference in Detroit.

Since the reported actions of the Public Hearings (Hydrogen Safety Report, Mar 2005), are merely recommendations of ICC's various Code Committees (i.e., fuel gas, fire), these actions could still receive dissenting public comments, and are not yet finalized until the conclusion of the 2004/05 Code Development Cycle. This conclusion will occur at the Final Action Hearings in Detroit this September.

For more information on International Code Development, visit:
www.iccsafe.org/news/pdf/factssheet.pdf or

For more information on Code Cycle procedures/schedules for the 2004/05 cycle, visit: www.iccsafe.org/cs/codes/2004-05cycle