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Interpretation Response #07-0047 ([Fluoro-Seal International] [Mr. Paul J. Crook])

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

Interpretation Response Details

Response Publish Date:

Company Name: Fluoro-Seal International

Individual Name: Mr. Paul J. Crook

Location State: TX Country: US

View the Interpretation Document

Response text:

Mar 26, 2007


Mr. Paul J. Crook                 Reference No. 07-0047
Safety & Environmental Manager
Fluoro-Seal International
16360 Park Ten Place, Suite 325
Houston, Texas 77084

Dear Mr. Crook:

This responds to your February 20, 2007 letter requesting clarification on Special
Provision 3 in § 172.102 of the Hazardous Materials Regulations (HMR; 49 CFR Parts
17 1-180). Specifically, you ask whether the appropriate hazard zone for “Hydrogen
fluoride, anhydrous, UN 1052”, is Hazard Zone B or Hazard Zone C.

As your letter indicates, the entry for “hydrogen fluoride, anhydrous, UN 1052” is assigned “Special Provision 3” in column 7 of the Hazardous Materials Table (HMT) in § 172.101 of the HMR. Special Provision 3 indicates that the material is poisonous by inhalation in Hazard Zone C. Special Provision 3 also references § 173.116(a) - Class 2, Assignment of Hazard Zone. Section 173.116(a) states that the hazard zone for a Division 2.3 material is assigned in Column 7 of the §172.101 table. The criteria specified in §173.116(a) for assignment of hazard zones are to be used when the § 172.101 table provides more than one hazard zone for a Division 2.3 material, or indicates that the hazard zone must be determined on the basis of the grouping criteria for Division 2.3. The hazard zone for hydrogen fluoride, anhydrous is assigned in Column 7 of the HMT; thus, Hazard Zone C is the correct hazard zone designation for this material.

I hope this answers you inquiry.



John A. Gale
Chef, Standards Development
Office of Hazardous Materials Standards

172.101, 172.102SP 3, 173.166(a)

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
172.102 Special provisions
173.166 Safety devices