The United States Pipeline and Hazardous Materials Safety Administration (“PHMSA”) addressed in a March 3rd letter a request for clarification of the Hazardous Materials Regulations (“HMR”) applicable to determining the reportable quantity (“RQ”) of a hazardous substance.

The question was posed in an August 19, 2016 letter from an ERM Senior Project Scientist (“ERM”).

ERM described the following scenario:

Nickel powder with a mean particle size of 101.1 micrometers is being shipped in a packaging totaling 1 metric ton.

ERM asks whether:

. . .the mean particle size can be used to determine if the nickel powder meets the RQ of a hazardous substance or whether the amount of nickel powder with a particle size exceeding the threshold size (i.e., 100 micrometers) must be determined.

PHMSA answers in the negative.

The agency states that the mean particle size cannot be used to determine if the nickel powder meets the RQ.

PHMSA states in support of this answer that:

. . .When determining whether a material in a package meets the RQ listed in Table 1 to Appendix A of § 172.101 (i.e., the hazardous substances table), the actual particle size must be used. The “₵” symbol associated with the entry “Nickel” in Table 1 denotes that the RQ is limited to metal particles having a diameter smaller than 100 micrometers. To meet the RQ for nickel, a package containing nickel must contain at 100 pounds of nickel particles less than 100 micrometers.

As a result, PHMSA states it cannot determine whether the ERM shipment meets the definition of a hazardous substance.

A copy of the letter can be downloaded here.