# Alloy Products Corp. — Hazardous Materials Safety Interpretation

**Citation:** 24-0058  
**Type / status:** guidance / guidance  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2024-10-01

24-0058 response to Alloy Products Corp. concerning 173.181, 178.50, 178.51.

## Document text

<<<PAGE 1>>>

U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
October 1, 2024
Mr. Raymond Woo
Director of Engineering
Alloy Products Corp.
1045 Perkins Ave
Waukesha, WI 53186
Reference No. 24-0058
Dear Mr. Woo:
This letter is in response to your June 25, 2024, email requesting clarification of the Hazardous
Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the use of DOT specification
cylinders for “UN3394, Organometallic substance, liquid, pyrophoric, water-reactive, 4.2 (4.3),
PG I.” You ask whether a DOT specification cylinder—such as a 4B or 4BA cylinder—is
authorized for the transportation of “UN3394, Organometallic substance, liquid, pyrophoric,
water-reactive, 4.2 (4.3), PG I.”
The answer is yes. The authorized packagings for “UN3394” in § 173.181(a) include
specification cylinders made from steel or nickel, provided the minimum design pressure is 175
psig. Both 4B (specifications found in § 178.50) and 4BA (specifications found in § 178.51)
cylinders are made of steel. Therefore, these cylinders are authorized packagings provided the
minimum design pressure is at least 175 psig and the cylinders—if equipped with valves—are
protected as required by § 173.181(a)(3).
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Alexander Wolcott
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

<<<PAGE 2>>>

Vore
24-0058
From: INFOCNTR (PHMSA)
To: Hazmat Interps
Subject: FW: IMDG question
Date: Wednesday, July 3, 2024 10:21:13 AM
Importance: High
Hello,
Below is a request for letter of interpretation.
Thanks,
Jonathon
From: Ray Woo <rayw@alloyproductscorp.com>
Sent: Tuesday, June 25, 2024 10:40 AM
To: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>
Subject: IMDG question
Importance: High
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.
To whom it may concern;
I have a question regarding what is considered a legal pressure receptacle in regard to the
IDMG code. Under packaging instruction, P400; a pressure receptacle can be used for
transporting a product classified under UN # 3394. Is a US DOT approved pressure cylinder,
such as a 4B or 4BA specification considered a legal pressure receptacle under this code? I
am looking for clarification on this issue. If you are not the appropriate person to send this to,
please advise who I should contact about this.
Regards.
Raymond Woo
Director of Engineering
Alloy Products Corp.
1045 Perkins Ave.
Waukesha, WI 53186
Email: Rayw@alloyproductscorp.com
(262) 832-8135 office (direct)

<<<PAGE 3>>>

(262) 542-6603 (general)
(262) 542-5421 (fax)

## Provenance

- Official: Yes
- Source: <https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2024-11/240058.pdf>
- Source ID: `phmsa`
- SHA-256: `c7fd27d2714291adf4b3cb5e3786c474eb95bf04642ada9782ecb19a14e2a90f`
- Retrieved: 2026-08-20T00:59:31.977Z
- Exported: 2026-08-23T16:33:59.700Z
- Document slug: `phmsa-interpretation-24-0058`

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