Interpretation Response #16-0080
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
August 2, 2016
Mr. William Weddle
NA Logistics/Warehousing Manager
1 Heilman Avenue
Willow Island, WV 26134
Reference No. 16-0080
Dear Mr. Weddle:
This letter is in response to your May 5, 2016 email and May 27, 2016 emails, attachments, and telephone conversation requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the transport of a two-part prepolymer-urethane system that becomes reactive when mixed. Specifically, you state this system consists of two cartridges—one that contains a curative and the other that contains a prepolymer—placed side by side in a manual or pneumatic dispenser with one point opening at the end that is designed to permit the combination of these materials before application.
In addition, you provide the following information:
• Your company sells two types of curatives it describes as “DM-5183, Part A Curative,” and “DPDM-28502, Part B Urethane Curative.” It has assigned both curatives the proper shipping description “UN 3082, Environmentally hazardous substance, liquid, n.o.s., 9 (miscellaneous), Packing Group (PG) III (Phenylmercuric acetate), Marine Pollutant.”
• Your company sells two types of prepolymers it describes as “DPDM-28502, Part A Urethane Prepolymer” and “DM-5183, Part B Urethane Prepolymer.” It has assigned Part A prepolymer the proper shipping description “UN 2810, Toxic liquid, organic, n.o.s, 6.1, PG II (4,4”-methylenedicyclohexyl diisocyanate),” and Part B prepolymer the proper shipping description “UN 2290, Isophorone diisocyanate mixture, 6.1 (poisonous), PG III.”
• Combined, the two cartridges contain either 200 mL or 400 mL of liquefied material. Part A and B materials create a mild exothermal reaction of 50 °C (122 °F) to 60 °C (140 °F) for a few minutes when mixed until the resin has cured.
We have paraphrased and answered your questions as follows:
Q1. You ask for the definition of “dangerous evolution of heat” under the HMR.
A1. While the HMR do not specifically define “dangerous evolution of heat” it is described as “an amount of heat sufficient to be dangerous to packaging or personal safety to include charring of packaging, melting of packaging, scorching of packaging, or other evidence” in examples provided in the following sections: §§ 171.15(b)(6); 171.16(b)(5); 172.102(c), Special Provision 130, paragraph (a); and 173.159a(b). Further, § 173.21(e) states that a material may not be placed in the same packaging, freight container, or overpack with another material if, when mixed, these materials may possibly cause a dangerous evolution or heat; flammable or poisonous gas or vapor; the formation of a corrosive material. In addition, § 173.24(e)(4) requires that the materials may not form an asphyxiant gas or unstable material.
Q2. You ask if the Part A and B prepolymer-urethane materials you described can be shipped as a two-part, joint plunger-type system in an inner packaging that is placed in a United Nations (UN) 4G fiberboard box.
A2. The answer is yes. Section 173.24a(c)(1)(ii) requires packages of mixed contents to meet the performance test criteria in Part 178 of the HMR and to conform to the relevant packaging sections of Part 173 that apply to each material within the packaging. You discussed with my staff the possibility that that material may be described as “UN 3269, Polyester resin kit, 3 (flammable liquid)”; however, please note this description applies to kits consisting of Class 3 and Division 5.2 (organic peroxide) only.
Q3. You ask if the HMR require completed packages that contain samples of the joint-plunger cartridge system you described to have a UN marking and certification.
A3. If shipped as a limited quantity and a determination is made that the mixing of the materials in the same packaging is not likely to cause a dangerous evolution of heat, flammable or poisonous gases or vapors, or corrosive materials, a UN standard packaging is not required. Limited quantity packagings are excepted from the specification packaging requirements of the HMR.
I hope this information is helpful. Please contact us if we be of further assistance.
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
171.15(b)(6), 171.16(b)(5); 172.102(c), 173.159a(b), 173.21(e), 173.24a(c)(1)(ii)
|§ 173.24a||Additional general requirements for non-bulk packagings and packages|