The California Department of Housing and Community Development has reversed its position on the use of corrugated stainless steel tubing as an approved gas piping material in the California Plumbing Code. A 45-day period for written comments on the proposals ends in mid-March.

The department's change of heart is due in part to comments received in two prior comment periods endorsing the use of CSST. Comments were also raised concerning safety issues in the use of CSST, but HCD found no evidence to support such concerns.

California's use of CSST is a public safety issue because of earthquakes. While flexible gas piping does the same job as rigid black iron pipe in providing natural gas to residential or commercial structures, its flexibility can better withstand the pulling, stretching and crushing that comes with earthquakes, resulting in fewer gas leaks and fires.

HCD's original proposal for the 2001 edition of the California Plumbing Code was to adopt the 2000 Uniform Plumbing Code developed by the International Association of Plumbing and Mechanical Officials, which does not list CSST as an approved material. The use of the flexible tubing was approved in the 1998 California Mechanical Code; the department has received no complaints regarding its existing use.

However, the department's detailed rationale supporting CSST stated that CSST has been approved as a permitted material for IAPMO's next published set of codes.

The rationale also stated that previously HCD "believed that additional studies were necessary before it could recommend adoption of CSST. Based on the significant amount of materials, information and testimony received ¿the department now believes that no further study is necessary to continue the existing approved use of CSST with the additional discretion allowed to local administrative authorities. However, in response to the concerns raised, the department is proposing to permit local administrative authorities enhanced authority to disapprove the use of CSST based on health, safety or performance considerations."

An HCD spokesman emphasized that the proposal was not a final decision of the department but a "proposed response" after review of the written comments. The department will make its final recommendation on CSST to the California Building Standards Commission after the current comment period expires.

A commission meeting is scheduled for March 20 to consider final recommendations on the California Plumbing Code.