Ask X3What does 49 CFR 173.323 (Ethylene oxide) require?
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As Ask X3, your fleet-compliance assistant, here is what 49 CFR 173.323 requires for packaging and transporting ethylene oxide:
Material and Compatibility Restrictions
* Prohibited Metals: Silver, mercury, copper, magnesium, or any of their alloys cannot be used in any part of the packaging, valves, appurtenance, or tanks that may come into contact with ethylene oxide liquid or vapor. (Copper alloys may only be used for gas mixtures if they contain no free acetylene that could form copper acetylene).
* Gaskets and Packing: All packing and gaskets must be made of materials that are compatible with ethylene oxide, do not lower its auto-ignition temperature, and do not react with the lading. Neoprene, natural rubber, and asbestos gaskets are strictly prohibited.
Authorized Non-Bulk Packagings
1. Glass or Metal Inner Packagings: Must be hermetically sealed, suitably cushioned in an outer package authorized by § 173.201(b), and capable of passing Packing Group I performance tests. Glass inner packagings are limited to 100 g (3.5 ounces) max; metal inner packagings are limited to 340 g (12 ounces) max. Each must be tested for leak-tightness in a hot water bath to achieve internal vapor pressure equal to 55 °C. Total quantity per outer package is capped at 100 g for glass or 2.5 kg (5.5 lbs) for metal.
2. Cylinders or UN Pressure Receptacles: Must be seamless or welded steel (no brazing) with a nominal capacity of no more than 115 L (30 gallons). They must not be liquid full below 82 °C (180 °F), must be tested for leakage at no less than 103.4 kPa (15 psig) before each refilling, and must feature a fusible type relief device (yield temperature of 69 °C to 77 °C) designed to prevent explosion in a fire (verified via CGA Pamphlet C-14 or equivalent). Cylinders over 4 L require pressurizing valves and insulation; cylinders over 19 L require eductor tubes.
3. 1A1 Steel Drums: Maximum capacity of 231 L (61 gallons) meeting Packing Group I standards. They must be all-welded, lagged, withstand a hydrostatic test of 690 kPa (100 psig), not be liquid full below 85 °C, and be marked "THIS END UP." Before each refilling, they must be tested for leakage at no less than 103 kPa (15 psig). They require a fusible type relief device (69 °C to 77 °C yield temperature) and must pass the CGA Pamphlet C-14 fire test without rupture.
Authorized Bulk Packagings
* Tank Cars: Class DOT 105 tank cars (built before March 16, 2009, must have at least a 20.7 Bar/300 psig test pressure; those built on or after March 16, 2009, must meet the applicable specification in § 173.314(c)). Tanks built after December 30, 1971, must have a thermometer well.
* Cargo Tanks: Specification MC 330 and MC 331 cargo tank motor vehicles.
* Portable Tanks: DOT 51 portable tanks.
General Bulk Requirements (Tank Cars, Cargo Tanks, and Portable Tanks)
* Pressure Relief: Relief devices must be set to function at 517 kPa (