May 5, 1999

Dockets Unit US Department of Transportation Room PL 401 400 7th Street, S.W. Washington, DC 20590

Re: RSPA-99-5143, "International Standards on the Transport of Dangerous Goods: Request for Comments"

Dear Mr. Roberts:

HMAC is an international, non-profit, educational organization devoted to promoting safety in the domestic and international transportation and handling of hazardous materials, substances and wastes. HMAC represents shippers, carriers of all modes, container manufacturers and reconditioners, emergency response and waste clean-up companies, and a variety of other companies and trade associations involved in the field of hazardous materials transportation.

We reviewed the RSPA Notice on requirements for substances dangerous to the environment and are generally supportive of this effort. HMAC is in agreement that the Packing Group III level of performance is adequate for these substances. We would like to offer the following specific comments on the criteria to define such substances which have been submitted for consideration at the July UN Subcommittee of Experts meeting by the United Kingdom and the United States:

1. Although no definition is provided for the term "substance," we assume this means a pure material that is not diluted by a hazardous or non-hazardous material. We also assume the proposal applies only to "pure substances" and not mixtures or solutions of pure substances. We would appreciate your verification of these two points.
    
2. It is our understanding that, under the proposal, substances presently in Classes 1-8 would not require a determination as to whether they also meet the criteria for dangerous to the environment. This would be an expensive, time-consuming exercise. Please verify that shippers will not be required to make these determinations.
    
3. HMAC is opposed to establishing an acute toxicity level (LC50/EC50) of less than 100 mg/l for substances being transported in bulk packagings having a capacity exceeding 3000 liters. Although there is an OECD level which covers this endpoint (Acute Toxicity Class III), the IOMC Coordinating Group for Harmonization of Chemical Classification Systems has recognized that not all sectors need to adopt all endpoints. We consider this level inappropriate for transport requirements and not consistent with criteria established for Marine Pollutants under the IMDG Code. The Code uses an acute toxicity limit of 1 mg/l or less to identify harmful substances in packaged form. Metam sodium, the substance cited in the Notice as being responsible for environmental damage to the Sacramento River due to a train derailment, has an LC50 of less than 1 mg/l according to data from GESAMP (Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection). Can RSPA clarify the scientific justification for the proposal to extend the limit to 100 mg/l? A preliminary review by several of our members indicates that a substantial number of substances fall within this higher range, many of which are shipped in bulk packagings and are not currently subject to regulation under Classes 1 through 8. It seems to us that capturing a large percentage of substances under the criteria would be counterproductive. HMAC believes the better approach is to focus on those substances with characteristics truly hazardous to the environment - substances possessing high acute toxicity and those which are not readily degradable or are bioaccumulative.
    
4. As RSPA points out in the Notice, OECD is developing guidance documents on substances that are difficult to test because of low water solubility and a standardized procedure for classifying mixtures. Since there are large numbers of poorly soluble substances and mixtures, HMAC is in agreement with RSPA that these documents must be completed before the UN Committee of Experts incorporates criteria into its Model Regulations on the Transport of Dangerous Goods. Our preference on the classification of mixtures would be to establish percentages to simplify determinations but permit testing if the manufacturer believes the mixture would not meet the criteria even though a component(s) exceeds the established percentage. This scheme would be similar to the existing Marine Pollutant provisions under the IMDG Code; however, we think setting an appropriate percentage for substances dangerous to the environment requires further study. HMAC also believes the guidance documents should address substances with a very high log Kow (above 7) which are so insoluble in water that they are generally presumed to present minimal potential for bioaccumulation. In addition, substances with molecular weights of greater than 1000 are generally not bio-available because of their molecular size. GESAMP has long recognized high log Kows and molecular weights as mitigating factors and has included them in its Hazard Evaluation System used by IMO for identification of Marine Pollutants. We understand these factors were discussed by OECD in its development of criteria but they do not appear in its classification scheme or explanatory notes. We strongly recommend the United States pursue incorporation of these two characteristics into the appropriate guidance document.
    
5. We suggest RSPA explore the possibility of establishing a minimum quantity for substances dangerous to the environment (below which the package would not be regulated), similar to what EPA has done in setting Reportable Quantities for Hazardous Substances. In this manner, small packages of these substances, which would not be expected to cause harm to the environment because of the quantity involved, would not be subject to regulation.

HMAC appreciates the opportunity to submit these comments on this important Notice. If you should have any questions on the issues we have raised, please feel free to contact HMAC at 202-289-4550.

Sincerely,

Jonathan Collom
President