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Interpretation Response #99-0062 ([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:

Apr 22, 1999


Mr. C. Vleugels                       Ref. No. 99-0062

VanHool N.V.

Bernard Van Hoolstraat 58

B-2500 Lier Koningshooikt


Dear Mr. Vleugels:

This is in response to your letter dated February 3, 1999, requesting clarification on the transportation of "Sodium Sulfide, hydrated with not less than 30% water, 8, UN 1849, 11" under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).  Specifically, you ask whether the provisions in §§ 173.32c(g)(2) and 173.32c(j) concerning bottom outlets and filling density apply to a solid material.

The bottom outlets and filling density provisions apply to liquid and flowable solid hazardous materials, not to solid or non-flowable solid hazardous materials. The provisions of § 173.32c(j) were developed to cover liquid and flowable solid hazardous materials transported in IM portable tank packagings. This provision was intended to minimize the risk of accidents resulting from slosh and the shift of the center of gravity.

This has been further clarified under Docket HM-215C, "Harmonization with the United Nations Recommendations, International Maritime Dangerous Goods Code, and International Civil Aviation Organization's Technical Instructions; Final Rule (64 CFR 10742) published March 5, 1999.  Under Docket HM-215C, § 173.32c(j) has been revised for consistency with the UN Recommendations.  The provision excluding non-flowable solids is broadened to include viscous liquids with a low flow rate.  In § 173.32c paragraph(j) is revised to read "except for a non-flowable solid or a liquid with a viscosity of 2,680 centistokes (millimeters squared per second) or greater at 20 degrees C, an IM portable tank or compartment thereof having a volume greater than 7,500 L (1,980 gallons) may not be loaded to a filling density of more than 20% and less than 80% by volume.  If a portable tank is divided by partitions or surge plates into compartments of not more than 7,500 L capacity, this filling restriction does not apply."

I hope this answers your inquiry.



Delmer F. Billings

Chief, Standards Development

Office of Hazardous Materials Standards


Regulation Sections

Section Subject
173.32 Requirements for the use of portable tanks