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Interpretation Response #99-0293 ([Denver Federal Center] [Mr. Carlos Arozarena])

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

Interpretation Response Details

Response Publish Date:

Company Name: Denver Federal Center

Individual Name: Mr. Carlos Arozarena

Location State: CO Country: US

View the Interpretation Document

Response text:

March 21, 2000


Mr. Carlos Arozarena                Ref. No. 99-0293
U.S. Geological Survey
Box 25046 M.S. 407
Denver Federal Center
Denver, CO 80225-0046

Dear Mr. Arozarena:

This is in response to your letter of December 14, 1999, and subsequent telephone conversations with Michael Johnsen, of my staff, concerning the classification of water samples under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).  You provided the following table of water samples regularly shipped by the USGS and its clients:

Analysis Type Water Sample Preparation
Preservative Concentration

(% by weight)

Oil and Grease

2 ml H2SO4(18M) / L sample


Phenol 1 ml H2SO4(18M) / 500 ml sample
Nutrient 1 ml H2SO4(1:7) / 125 ml sample
Cyanide 5 ml NaOH (5N) / 240 ml sample
Volatile Organics 0.1 ml H.L. (12M) / 40 ml sample
Metals (RA/FA) 2 ml HNO3 (7.6) / 250 ml sample
Mercury Sample 10 ml HNO3 (15.8M) /240 ml sample
0.035 g K2Cr2O7

In addition, you included a letter issued by this office on December 13, 1993, which listed several corrosive materials that were so dilute they are excepted from the HMR.  According to our letter, H2S04 (sulfuric acid) in water solutions at concentrations of 0.35% by weight or less are excepted from the HMR.

From the information you have provided, we have made the following recommendations for classifying these materials:

  • Based on this exception, three of the Analysis Types in question which contain H2SO4  (Analysis Type: Oil and Grease; Phenol; and Nutrient) are not regulated by the HMR.
  • Three water samples (Analysis Type: Cyanide; Volatile Organics; and Metals (RA/FA)) should be tested to determine if they meet the definition for corrosive material.  It is the opinion of this Office that these three samples are not corrosive to skin.  However, these preparations may be corrosive to metal (steel and/or aluminum).
  •  The sample containing HNO3, (nitric acid) and K2Cr2O7, (potassium dichromate) (Analysis type: Mercury Sample) is a corrosive material.  Tests for skin corrosion should be conducted to determine the packing group.

I hope this satisfies your request.



Delmer F. Billings
Chief, Standards Development
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table