# Symmetricom — Hazardous Materials Safety Interpretation **Citation:** 08-0154 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2008-06-25 08-0154 response to Symmetricom concerning 173.124. ## Document text <<>> 1200 New Jersey Ave.. S.E. Washington. DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration JUN 2 5 2008 Mr. Gerald M. Beauchesne Facility Manager Symmetricom 34 Tozer Road Beverly, MA 01915-5510 Ref. No. 08-0 154 Dear Mr. Beauchesne: This responds to your May 16,2008 letter requesting an update of an interpretation you received from the Office of Hazardous Materials Regulation of the Research and Special Program Administration (RSPA), the predecessor agency to the Pipeline and Hazardous Materials Safety Administration, regarding the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 17 1 - 180) to a device containing rubidium. Specifically, you request clarification on an interpretation indicating the device containing rubidium does not pose a transportation hazard as a flammable solid and whether the interpretation can be extended to Class 4 hazardous materials. You provide a copy of the letter your company received in November 1984 stating the opinion of the Office that "a frequency standard (device) containing less than one gram of rubidium does not pose a transportation hazard as a flammable solid and consequently is not regulated as such." You also indicate that your company continues to produce frequency devices with less than one gram of rubidium for use in atomic clocks. Finally, in telephone conversations with our Office, you state that tests conducted by your company on components of the devices in which the glass cells or lamps containing rubidium are broken do not show spontaneous ignition or flammability when exposed to air or water. Based on the information provided and on previous interpretation by RSPA, it is the opinion of this Office that a frequency device containing less than one gram of rubidium for use in atomic clocks is not subject to the HMR as a Class 4 hazardous material. I hope this information is helpful. Please contact us if you require additional assistance. Sincerely, ,&&L ) f, John A. Gale, V ' Chief, Standards Development Office of Hazardous Materials Standards <<>> 34 Tozer Road Beverly, MA 01915-5510 Tel: (978) 927-8220 Fax: (978) 927-4099 U.S. Department of Transportation PHH- 10 1200 New Jersey Avenue, SE East Building, 2nd Floor Washington, DC 20590 Attention: Mr. Edward T. Mazzullo May 16,2008 I Dear Mr. Mazzullo: We recently spoke to Dr. Ke, Offices of Hazardous Materials Technology - PHH-2 1 -Sciences, about a letter our company received from DOT back in November 1984 (see attached). This letter states that our Rubidium product line, cantaining less than one gram of rubidium, does not pose a transportation hazard. Our discussion with Dr. Ke was centered around updating the statement outlined and the date of this letter. Dr Ke stated that this document is still accurate but after a detailed discussion with Dr. Ke, and under his advisement, we are sending this letter to you to request an updated version on the following issues: 1. The original company name and address has changed. The original company was Ball Efratom Div out of Irving Cal, which is now: J < , - - . E. :!,!,: : , . . ;Sy-s&etri&di . .: :.,.,: ... , > .. . . . . - ;I:. :.-c , .: . .?Cbtf~brate Headquarters 4 - ' .. ;23,0O:Orchard Parkway ;- .:-:; :. 3 - : .4 ?S&.!Jose, CA 95 13 1 I: . ; ;;:USA . . 2. We would also like a clarification on the statement of a flammable solid. Dr. Ke's interpretation of this sentence is that we are covered for all divisions of Class 4. If this is indeed correct could we please get this changed from flammable solids to Class 4 (Flammable Solids) in total? The amount of Rubidium in today's current product is the same as what was described in 1984, which is less than 1 gram of Rubidium. Symmetricom is a manufacture of time and frequency devices using both Cesium and Rubidium in Atomic Clocks. If you have any questions, please do not hesitate to call. Facility Manager. 978-232- 1485 (ph) , . r 978-265-2521 (cell) - , , . . . . - 978-927-4099 (f&)..i ; ' :. I - : ' i ' .: :': : E-mail: GBeauchesae@,s~metricom.com - 34 Tozer Rd, Beverly, MA 0 19 15 7 - I ; ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `18c3930a297b29f4c74e1ddebea2eec4b021cafc74dbf204326358e3fea28921` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T05:49:50.318Z - Document slug: `phmsa-interpretation-08-0154` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Symmetricom" ], "individuals": [ "Mr. Gerald M. 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