---
kind: "section"
citation: "49 C.F.R. § 173.336"
title: "49"
number: "173.336"
heading: "Nitrogen dioxide, liquefied, or dinitrogen tetroxide, liquefied."
url: "https://uscodex.org/cfr/49/173.336"
---

# §173.336. Nitrogen dioxide, liquefied, or dinitrogen tetroxide, liquefied.

- (a) Nitrogen dioxide, liquefied, or dinitrogen tetroxide, liquefied, must be packaged in specification or UN cylinders as prescribed in [§ 173.192](/cfr/49/173.192.md), except valves are not authorized. UN tubes and MEGCs are not authorized for use. Cylinders must be equipped with a stainless steel valve and valve seat that will not deteriorate in contact with nitrogen dioxide. Each valve opening must be closed by a solid metal plug with tapered thread properly luted to prevent leakage. Transportation in DOT 3AL cylinders is authorized only by highway and rail.
- (b) Each UN pressure receptacle must be cleaned in accordance with the requirements of ISO 11621 (IBR, see [§ 171.7](/cfr/49/171.7.md) of this subchapter). Each DOT specification cylinder must be cleaned according to the requirements of GSA Federal Specification RR-C-901D, paragraphs 3.3.1 and 3.3.2 (IBR, see [§ 171.7](/cfr/49/171.7.md) of this subchapter). Cleaning agents equivalent to those specified in RR-C-901D may be used; however, any cleaning agent must not be capable of reacting with oxygen. One cylinder selected at random from a group of 200 or fewer and cleaned at the same time must be tested for oil contamination in accordance with Specification RR-C-901D, paragraph 4.3.2 (IBR, see [§ 171.7](/cfr/49/171.7.md) of this subchapter) and meet the standard of cleanliness specified therein.

## Notes

### Amendments

[71 FR 33885, June 12, 2006]

### Authority

Authority: 49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and 1.97.

### Amendments

[71 FR 33885, June 12, 2006]