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Interpretation Response #09-0084 ([Syncro Medical Innovations, Inc.] [Mr. Lalit Sabramanian])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Syncro Medical Innovations, Inc.

Individual Name: Mr. Lalit Sabramanian

Location State: OH Country: US

View the Interpretation Document

Response text:

March 21, 2011




Mr. Lalit Sabramanian

Product Engineer

Syncro Medical Innovations, Inc.

20 W Federal Street, Suite M5B

Youngstown, OH 44503

Reference No. 09-0084

Dear Mr. Sabramanian:

This is in response to your letter concerning the provision in § 173.21(d) under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) that forbids from transportation by aircraft a package that has a magnetic field measurement of more than 0.00525 gauss at a distance of 4.5 meters (15 feet) from any surface of the package. We have paraphrased your questions and answered them in the order you provided. We apologize for the delay in responding and any inconvenience this may have caused.

The HMR also authorize use of the International Civil Aviation Organization (ICAO) Technical Instructions for the Safe Transport of Dangerous Goods by Air (Technical Instructions) when all or part of the transportation of a hazardous material is by aircraft, so we have included information relative to these requirements. Under the provisions of §§ 171.22-171.24, the HMR give shippers and carriers the option of preparing shipments of hazardous materials offered or intended for transportation by aircraft in conformance with the ICAO Technical Instructions.

Q1. The earth"s magnetic field is 0.5 gauss. Why then does § 173.21(d) forbid from transportation by aircraft a package with a magnetic field measurement greater than 0.00525 gauss at a distance of 4.5 meters from any surface of the package when this measurement is 100 times greater than that of the earth? Is this a typographical error or are the units expressed in teslas?

A1. The magnetic field measurement in § 173.21(d) is expressed in gauss and is based on tests conducted by the Federal Aviation Administration (FAA) to determine when a magnetic material would adversely affect the operation of an aircraft. In a 1987 advisory, entitled "Preparation and Loading of Magnetic Materials for Air Transportation" (enclosed), the FAA concluded a material with a measurable magnetic field of more than 0.00525 gauss at a distance of 4.5 meters from any surface of the package can cause an aircraft"s magnetic compass or compass master unit to have "compass deviations as high as 125 degrees, cause navigation errors, and jeopardize the safety of the transporting aircraft." The FAA is especially concerned magnetic fields of this strength will affect older or smaller aircraft because they may have magnetic master units located inside or near their cargo compartments. Under the HMR, packages with magnetic field of 0.00525 gauss or less at a distance of 4.5 meters are considered non-magnetic and are not subject to regulation.

Effective January 1, 2011, the ICAO revised its requirements for transporting magnetic materials by aircraft in its 2011-2012 edition of the Technical Instructions. These changes substantially revised the requirements for shipping magnetized material in former Packing Instruction (PI) 902, moved this revised language to new PI 953, and deleted PI 902. Specifically, the new requirements permit magnetized materials to be transported by aircraft with magnetic field strengths that can cause a compass deflection of 2 degrees or more at a distance of 2.1 meters but not more than 2 degrees at a distance of 4.6 meters (equivalent to 0.418 amperes per meter (A/m) or 0.00525 Gauss measured at a distance of 4.6 meters). Also, PI 953 excepts magnetized materials from all other requirements under the ICAO Technical Instructions provided they comply with the following:

1) the shipper must make prior arrangements with the operator (i.e., carrier) identifying the magnetized material. The dangerous goods transport document requirements of Part 5;4 are not applicable provided alternative written or electronic documentation includes the words "magnetized material" in association with the description of the goods;

2) the package must bear the magnetized material handling label (as shown in Figure 5-24 (enclosed) of Part 5; Chapter 3 of the 2011-2012 ICAO Technical Instructions);

3) the operator must stow the packaged magnetized material in accordance with 7;2.10; and

4) the incident reporting requirements of 7;4.4 must be met.

Finally, PI 953 requires magnetized material with a field strength sufficient to cause a compass deflection of more than 2 degrees at a distance of 4.6 meters to be transported only with the prior approval of the appropriate authority of the State (i.e., country) of origin and the State of the operator.

Q2. If the magnetic field measurement in § 173.21(d) is not an error, is this a field value relative to the earth"s magnetic field of 0.5 gauss?

A2. Yes. Also see Answer A3.

Q3. Do you recommend any specific test to be able to measure magnetic field strength that is this low?

A3. The HMR do not prescribe any test methods to measure a magnetic field strength. Please note, however, that the ICAO Technical Instructions provide several methods for measuring magnetic field strength in § 9.2.1(d).

Q4. Is any special labeling or documentation required for us to transport this package?

A4. Under the HMR, a magnetized material is either not of sufficient magnetic strength to be regulated or is forbidden in transportation (see § 173.21(d)); therefore, no labels or shipping papers are required. However, the ICAO Technical Instructions require magnetized material that is not excepted from regulation to be described on a shipping paper as "UN 2807, Magnetized material, 9 (miscellaneous);" and marked and packaged as prescribed in PI 953. The package must also be labeled with a MAGNETIZED MATERIAL label that complies with the image in Figure 5-24 discussed earlier in Answer A1. Also, packages correctly labeled with the MAGNETIZED MATERIAL label under the ICAO Technical Instructions do not need to bear the Class 9 (MISCELLANEOUS) label (see § 3.2.11).

I hope this satisfies your request.


T. Glenn Foster

Chief, Regulatory Review and Reinvention Branch

Standards and Rulemaking Division



Regulation Sections

Section Subject
173.21 Forbidden materials and packages