# Centers for Disease Control and Prevention — Hazardous Materials Safety Interpretation

- **operation:** document
- **citation:** 25-0044
- **title:** Centers for Disease Control and Prevention — Hazardous Materials Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2025-08-07
- **effective on:** Not available
- **summary:** 25-0044 response to Centers for Disease Control and Prevention concerning 173.134.
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- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-25-0044.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-25-0044
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-08/250044.pdf
**body:**

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1200 New Jersey Avenue, SE
Washington, DC 20590
U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
August 7, 2025
Keri Kolb
Centers for Disease Control and Prevention
3156 Rampart Road
Mail Stop 2
Fort Collins, CO 80521
Reference No. 25-0044
Dear Ms. Kolb:
This letter is in response to your April 10, 2025 email requesting clarification of the Hazardous
Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to materials classified and
described by the International Civil Air Organization (ICAO) as Division 6.2 infectious
substances. Specifically, you request clarification on the proper classification (i.e., Category A or
B) of chimeric viruses (non-culture). In your incoming email, you reference the indicative list
provided in the ICAO Technical Instructions for the Safe Transport of Dangerous Goods by Air
(ICAO Technical Instructions) and the International Air Transportation Association Dangerous
Goods Regulations.
PHMSA notes that the Categories A and B described in the HMR at § 173.134 do not
incorporate by reference nor are they intended to mirror the Categories A and B for Division 6.2
infectious substances listed in the ICAO Technical Instructions. For purposes of transporting
infectious substances within the United States, the indicative list of example Category A
infectious substances contained in the ICAO Technical Instructions should be considered solely
as informational guidance to assist in appropriately classifying Category A and B infectious
substances commensurate with the relevant HMR criteria. The ICAO list is not exhaustive and
may omit new or emerging pathogens and require amendments from time to time based on the
latest available data. Therefore, the indicative ICAO list is not included in the HMR as it is not
intended to be regulatory in nature.
Furthermore, for purposes of the HMR, it is the shipper’s responsibility to properly classify the
material in accordance with § 173.134 classification criteria for Division 6.2 infectious
substances. Therefore, chimeric viruses, whether in a culture or non-cultured form, must be
classified in accordance with the criteria in § 173.134 and assigned the appropriate category for
transportation.

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I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Dirk Der Kinderen
Chief, Standards and Development Branch
Standards and Rulemaking Division

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25-0045
Horne
Jones, Jessie Jane (PHMSA)
From: INFOCNTR (PHMSA)
Sent: Thursday, April 10, 2025 1:08 PM
To: Hazmat Interps
Subject: FW: CFR 49 IATA clarification about Chimeric viruses UN2814
Hello Hazmat Interps,
Please see the below request for leer of interpretaon.
The mailing address for the request is:
Keri Kolb
Centers for Disease Control and Prevention
3156 Rampart Rd
Mail Stop 02
Fort Collins, CO 80521
Thanks,
Jonathon, HMIC
From: Kolb, Keri (CDC/NCEZID/DVBD/ADB) <ryq1@cdc.gov>
Sent: Thursday, April 10, 2025 10:05 AM
To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>
Subject: CFR 49 IATA clarification about Chimeric viruses UN2814
You don't often get email from ryq1@cdc.gov. Learn why this is important
CAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links
or open attachments unless you recognize the sender and know the content is safe.
Hello,
I was wondering if you would be able to assist me with clarification on chimeric viruses under the UN2814
classification.
I have a question about a Category A shipment item.
On the list for Category A items in Table 3.6.D (2024 Iata & CDF 49 book) it indicates that viruses such as West Nile virus
(cultures only), Eastern Encephalitis (cultures only) and Dengue virus (cultures only) are considered category A items.
We have several variants of these items that we ship and need clarification as to whether or not these items would be
considered category A items in the eyes of the government. Some of these examples are the following. They are what is
considered chimeric viruses.
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ChimeriVax West Nile virus
Eastern equine encephalitis/Sindbis Chimeric virus
These items are not cultures but "chimeric" viruses of items that are on the CAT A list. This is the definition of a chimeric
virus per the USDA:
A chimera or chimeric virus is a virus that contains genetic material derived from two or more distinct viruses. It is defined
by the Center for Veterinary Biologics (part of the U.S. Department of Agriculture's Animal and Plant Health Inspection
Service) as a "new hybrid microorganism created by joining nucleic acid fragments from two or more different
microorganisms in which each of at least two of the fragments contain essential genes necessary for replication."[1] The
term genetic chimera had already been defined to mean: an individual organism whose body contained cell populations
from different zygotes or an organism that developed from portions of different embryos.[citation needed] Chimeric
flaviviruses have been created in an attempt to make novel live attenuated vaccines.[2] ( i got this from Wikipedia)
Do we ship these items as Cat A items, based on the name, or can we ship them as a CAT B because it's not a culture?
I also need some kind of documentation that would support the finding so that we can have it on file or even better yet,
someplace where I can go to get this clarified within the government. Can you please advise?
Thank you!
Keri Kolb
Keri Kolb
Administrative Support Specialist
US Department of Health and Human Services
Centers for Disease Control and Prevention
Ryq1@cdc.gov
970-225-4293
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