PHMSA letter of interpretation

So Called "Memorandum of Understanding" between DOT and EPA

Pipeline and Hazardous Materials Safety Administration · Dec 13, 1993 · Reference No. 93-0232

PHMSA says to use caution with this letter. The percentages discussed in this interpretive letter are found in 40 CFR § 136.3, Table II, footnote (3) and are there as a result ot the 1979 letter, Allan to Miller

This is in response to your letter of August 13, 1993, in which you ask if an exception, provided by a letter signed April 11, 1979 by Mr. Alan I. Roberts, Associate Director for Hazardous Materials Safety of the Research and Special Programs Administration, (RSPA), is still valid.

This exception from the Hazardous Materials Regulations, (HMR; 49 CFR Parts 171-180), concerns the shipment of water samples containing limited quantities of various corrosive, Class 8, materials. the materials mentioned in the exception were:

Hydrochloric acid, (HCl), in water solutions at concentrations of 0.04% by weight or less;
Mercury chloride, (HgCl2), in water solutions at concentrations of 0.004% by weight or less;
Nitric acid, (HNO3), in water solutions at concentrations of 0.15% by weight or less;
Sulfuric acid, (H2SO4), in water solutions at concentrations of 0.35% by weight or less;
Sodium hydroxide, (NaOH), in water solutions at concentrations of 0.080% by weight or less; and
Phosphoric acid, (H3PO4), in water solutions at concentrations yielding a pH range between 4 and 2.

It is our opinion that this exception is still valid. The above listed materials in these concentrations identified in water are not subject to the HMR.

I hope this information is helpful. If you have further questions, do not hesitate to contact us.

A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.