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Interpretation Response #99-0175 ([Mr. C. Vleugels])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name: Mr. C. Vleugels

Country: BE

View the Interpretation Document

Response text:

September  23, 1999


Mr. C. Vleugels                             Ref No. 99-0175

VanHool N.V.

Bernard Van Hoolstraat 58

B-2500 Lier Koningshooikt


Dear Mr. Vleugels:

This is in response to your letter dated June 25, 1999, requesting clarification on determining whether your material, Sodium Sulfide, UN 1849, is a "flowable" or a "non-flowable" solid as it relates to provisions in § 173.32c (g)(2) of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).

As used in § 173.32c(g)(2), a "flowable" solid is a solid material (e.g., crystal, powder, pellet, etc.) that moves in a smooth and uninterrupted movement through the valves of a tank. Sodium Sulfide in its crystal or powder form is considered a "flowable" solid if it flows freely through the valves.  A "non­flowable" solid is a solid material in a cake or other solid form that does not flow in a smooth and uninterrupted movement through the tank valves.  If moisture affects your material causing clumping or other solidification that interrupts free flow or movement through the valves of the tank, your material is considered a "non-flowable" solid.

I hope this answers your inquiry.



Delmer F. Billings

Chief, Standards Development

Office of Hazardous Materials Standards


Regulation Sections

Section Subject
171.8 Definitions and abbreviations