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Interpretation Response #16-0171 ([Alaska Airlines, Inc.] [Mr. Mike Tobin])

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

Interpretation Response Details

Response Publish Date:

Company Name: Alaska Airlines, Inc.

Individual Name: Mr. Mike Tobin

Location State: WA Country: US

View the Interpretation Document

Response text:

March 15, 2017

Mike Tobin
Manager Dangerous Goods       
Alaska Airlines, Inc.
P.O. Box 68900 - SEADG
Seattle, WA  98168

Reference No. 16-0171

Dear Mr. Tobin:

This letter is in response to your October 19, 2016, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to materials subject to transport regulations by air.  You describe in your email a scenario in which a ramp service agent experienced burning of the eyes and throat after having entered the lower cargo compartment on a passenger-carrying aircraft, where he was exposed to a material leaking from a drum.  You further explain that while the drum contained formalin mixed with sea water to a 4% concentration that was not regulated in accordance with special provision A189, the effect experienced by the agent is more aligned with special provision A35.  Specifically, you state your belief that special provisions A35 and A189 assigned to “UN 3334, Aviation regulated liquid, n.o.s. (formalin)” create confusion and ask if either special provision supersedes the other in this instance.

Under the Hazardous Materials Table (HMT) in § 172.101, “UN 3334, Aviation regulated liquid, n.o.s.” is listed as a Class 9 material and is assigned special provisions A35 and A189.  By definition, Class 9 means a material which presents a hazard during transportation but which does not meet the definition of any other hazard class.  This class includes “any material which has an anesthetic, noxious or other similar property which could cause extreme annoyance or discomfort to a flight crew member so as to prevent the correct performance of assigned duties.”  

Special provision A189 explains that concentrations of formaldehyde solution with less than 10% formaldehyde and, in this instance, formalin solution (i.e., 1-2% formaldehyde solution) are generally not subject to the HMR.  Nonetheless, it is the shipper’s responsibility to properly classify their material.  Special provision A35 explains that material described as “Aviation regulated liquid” would create discomfort to crew members on an aircraft, preventing the correct performance of assigned duties in the event of spillage or leakage of the material.  

With respect to your concern about precedence of the two special provisions, neither special provision A35 nor A189 has precedence.  If it is determined that the formalin solution (1-2% formaldehyde solution) described in your scenario meets the criteria of special provision A35, it is subject to the regulations by air as a Class 9 material.

I hope this information is helpful.  Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table