Interpretation Response #24-0072
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Council on Safe Transportation of Hazardous Articles (COSTHA)
Individual Name: Mr. Frank Lopez
Location State: NY Country: US
View the Interpretation Document
Response text:
March 24, 2025
Mr. Frank Lopez
Regulatory Compliance Specialist
Council on Safe Transportation of Hazardous Articles (COSTHA)
101 Ridge Street, Suite I
Glens Falls, NY 12801
Reference No. 24-0072
Dear Mr. Lopez:
This letter is in response to your August 19, 2024, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to an article. Specifically, you ask about a valve for internal combustion engines (e.g., automobile or aircraft engines) containing a small quantity of sodium or potassium sodium alloy encapsulated and sealed within the valve cavity by welding.
We have paraphrased and answered your questions as follows:
Q1. Is the guidance issued in an August 20, 2002, letter of interpretation (LOI) under Reference No. 02-0159 still valid?
A1. Yes. The guidance issued in an August 20, 2002, LOI under Reference No. 02-0159 is still valid. It remains our determination that 1.6 grams or less of sodium or potassium sodium alloy encapsulated and sealed by welding within a valve for an internal combustion engine is in a quantity and form that does not pose a hazard in transportation and—therefore—these articles are not subject to the HMR. This determination does not apply to valves containing more than 1.6 grams of sodium or potassium sodium alloy, which must be shipped in conformance with all applicable requirements of the HMR.
Q2. Are engine exhaust valves containing 1.6 grams or less of sodium or potassium sodium alloy encapsulated and sealed by welding within a valve for an internal combustion engine—as described in LOI Reference No. 02-0159—subject to the HMR when offered for carriage by any mode of transportation to, from, or within the United States?
A2. No, see answer A1. It should be noted that when the engine exhaust valves are transported outside the United States, they may be subject to the regulations of the country to, from, or through which they are being transported. Other international regulations may also apply, including the International Civil Aviation Organization's Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO TI) or the International Maritime Dangerous Goods (IMDG) Code.
We hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division