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Interpretation Response #16-0116

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

Interpretation Response Details

Response Publish Date:

Company Name: UL Supply Chain & Sustainabilty

Individual Name: Kevin Skerrett

Location State: NY Country: US

View the Interpretation Document

Response text:

May 29, 2019

Mr. Kevin Skerrett
Senior Regulatory Specialist
UL Supply Chain & Sustainability
23 British American Boulevard
Latham, NY 12110

Reference No. 16-0116

Dear Mr. Skerrett:

This letter is in response to your June 29, 2016, email and subsequent telephone conversation with a member of my staff requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to methanol solutions when shipped domestically and internationally.

In your email, you note that methanol has two entries in the Hazardous Materials Table (HMT):

  • The first entry describes methanol as a Class 3, PG II material.  The letter "D" in Column 1 of the HMT identifies this material as being suitable for domestic transportation.
  • The second entry describes methanol as a Class 3, (6.1), PG II material. Column 1 of the HMT depicts both the letter "I" and the "plus" (+) sign.  The letter "I" identifies proper shipping names appropriate for describing materials in international transportation. The (+) sign fixes the proper shipping name, hazard class, and packing group for that entry without regard to whether the material meets the definition of that class, packing group, or any other hazard class definition. 

You ask a series of questions related to the applicability of the Division 6.1 (Toxic) subsidiary hazard to methanol. Your questions are paraphrased and answered below:

Q1. You ask whether human health experience takes precedent over the classification criteria determined by animal testing presented in § 173.132(a)(1) through (c).

A1. The answer is yes. Animal testing data obtained in accordance with § 173.132 may be used when there is an absence of data on human toxicity. For the purposes of the HMR, a Division 6.1 (Toxic) material is a material, other than a gas, which is known to be so toxic to humans as to afford a hazard to health during transportation, or which, in the absence of adequate data on human toxicity is presumed [emphasis added] to be toxic to humans because it falls within any of the categories presented in § 173.132 when tested on laboratory animals.

Q2. You ask whether the International Maritime Dangerous Goods Code (IMDG Code), the International Civil Aviation Organization Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO Technical Instructions), and the United Nations Model Regulations on the Transport of Dangerous Goods (UN Model Regulations) concur with the HMR with respect to the use of human health experience over animal testing data.

A2. The answer is yes. The IMDG Code in 2.6.2.2.2, the ICAO Technical Instructions in 2.6.2.2.2, and the UN Model Regulations in 2.6.2.2.2 state that in making packing group assignments, account shall be taken of human experience in instances of accidental poisoning and special properties possessed by any individual substance, such as liquid state, high volatility, any special likelihood of penetration, and special biological effects. Paragraph 2.6.2.2.3 of all three standards further states that in the absence of human experience the groupings shall be based on data obtained from animal experiments.

Q3. You ask whether the statements in § 173.132(a) and 2.6.2.2.2 of the IMDG Code, the ICAO Technical Instructions, and the UN Model Regulations apply only to the listed "pure" material or is it implied for all mixtures and solutions of the material.

A3. The statements in § 173.132(a) and 2.6.2.2.2 of the IMDG Code, the ICAO Technical Instructions, and the UN Model Regulations regarding the use of human experience is not specific to a listed "pure" material and can be applied to materials listed in the HMT and their solutions.

Q4. In your email, you note that no experimental oral, dermal, or inhalation human toxicity values exist for methanol. You ask if a shipper can apply animal testing data for a mixture or solution of a listed substance, such as methanol, for which there is no human experience data for a specific concentration.

A4. It is the shipper's responsibility to properly classify and describe a hazardous material. The international entry for methanol is assigned a (+) sign in Column 1 of the HMT, and this means that the material is known to pose a risk to humans. The (+) sign no longer needs to be considered when the mixture or solution does not exhibit the same hazard to humans. In this example, the material may be described using an alternative proper shipping name that represents the hazards posed by the material. See § 172.101(b)(1).

Q5. You ask what constitutes acceptable evidence that a mixture or solution is significantly different or poses no hazard to humans.

A5. To make that determination, you must identify available human toxicity data for methanol and use that data to determine if a mixture or solution is still toxic. If you find that the hazards to humans are significantly different from that of the pure methanol or that no hazard to humans is posed, the material may be described using an alternative shipping name that represents the hazards posed by the material.

Q6. You ask whether § 172.101(b)(1) allows the shipper to omit the Division 6.1 (Toxic) subsidiary hazard or only select an alternative shipping name that describes the material as toxic.

A6. See A5.

Q7. You ask whether a shipper must describe a solution that contains methanol and assigned an alternate proper shipping name with a Division 6.1 (Toxic) subsidiary hazard.

A7. A solution containing methanol must be described by an appropriate proper shipping name from the HMT that reflects the hazards of the solution. If you find that the hazards to humans are significantly different from that of the pure methanol or that no hazard to humans is posed, the material may be described using an alternative shipping name that represents the hazards posed by the material. In this instance, the most appropriate description for the material shall be determined in accordance with § 172.101(c)(10).
 
Q8.  You ask whether an approval from the Associate Administrator is required to use an alternate proper shipping name.

A8. The approval from the Associate Administrator to use an alternate proper shipping name is required for instances when a (+) sign is assigned to a mixture or solution according to § 172.101(b)(1). In the case of methanol, the (+) sign is affixed to a pure substance. If you were to dilute that pure substance in a solution to a point at which the hazard to humans is significantly different than the pure substance or where no hazard to humans is posed, the (+) sign would no longer be applied to that material, and the shipper would be required to assign a new proper shipping name to the material based on its current properties and hazard characteristics.

Q9. You ask whether the answers to A6 through A8 differ if the material is offered for international transport.

A9. The answer is no.  The IMDG Code in 3.1.3, the ICAO Technical Instructions in 3.1.3, and the UN Model Regulations in 3.1.3 state that a mixture or solution is not subject to the regulations if the characteristics, properties, form or physical state of the mixture or solution are such that it does not meet the criteria, including human experience criteria, for inclusion in any class.

Q10. In your email, you note that in 2003 the United States submitted a proposal to the United Nations Sub-Committee of Experts on the Transport of Dangerous Goods (the Sub-Committee) to amend the existing entries for methanol to add a PG III entry for methanol and methanol solutions without the Division 6.1 (Toxic) subsidiary hazard.  You further noted that this proposal was not adopted because the Sub Committee determined that the Division 6.1 (Toxic) subsidiary hazard label was justified by human experience not only for the pure substance, but also for dilute solutions. Based on this, you ask whether dilution is an acceptable method to omit the Division 6.1 (Toxic) subsidiary hazard from methanol solutions in international transport.

A10. The criteria for assigning a UN number and a proper shipping name are outlined in Chapter 2 of the IMDG Code, the ICAO Technical Instructions, and the UN Model Regulations. As described in 2.0.2.6 in both the UN Model Regulations and the IMDG Code (2.0.3.6 in the ICAO Technical Instructions), for a solution or mixture when the hazard class, the physical state or the packing group is changed in comparison with the listed substance, the appropriate n.o.s. entry shall be used including its packaging and labelling provisions. A solution or mixture of methanol may not be subject to the IMDG Code, the ICAO Technical Instructions, or the UN Model Regulations if the characteristics, properties, form or physical state of the mixture or solution are such that it does not meet the criteria, including human experience criteria, for inclusion in any class. The fact that the Sub-Committee did not adopt the 2003 proposal has no impact on how mixtures or solutions should be classified.

Q11. You ask whether there is a negligible or de minimis concentration of methanol below which the toxic hazard has dropped to a negligible risk.

A11. There is no definitive concentration that would except a mixture or solution containing methanol from the HMR; however, if the concentrations are so low that the material no longer meets the criteria for any hazard class, the material may no longer be considered hazardous.  Each mixture or solution must be evaluated in the form it will be shipped to determine whether it should be considered a hazardous material.

Q12. You ask whether there was any indication from the Sub-Committee, including approval, for calculating or testing to omit the Division 6.1 (Toxic) subsidiary hazard for mixtures or solutions containing methanol.

A12. The criteria for assigning a UN number and a proper shipping name are outlined in Chapter 2 of the IMDG Code, the ICAO Technical Instructions, and the UN Model Regulations. As described in 2.0.2.6 in both the UN Model Regulations and the IMDG Code (2.0.3.6 in the ICAO Technical Instructions), for a solution or mixture when the hazard class, the physical state or the packing group is changed in comparison with the listed substance, the appropriate n.o.s. entry shall be used including its packaging and labelling provisions. A solution or mixture of methanol may not be subject to the IMDG Code, the ICAO Technical Instructions, or the UN Model Regulations if the characteristics, properties, form or physical state of the mixture or solution are such that it does not meet the criteria, including human experience criteria, for inclusion in any class.

Q13. You ask whether the Sub-Committee has further discussed the classification of mixtures and solutions of methanol since 2003.

A13. The answer is no. Since 2003 there have been no further discussions specific to the transport of mixtures or solutions of methanol.

Q14.  You ask whether a shipper can use calculations and methods authorized by the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).

A14. The answer is no. When an entry is assigned a (+) sign in Column 1 of the HMT, the hazard class and packing group are fixed, regardless of whether that material meets the definition of that hazard class, packing group, or any other hazard class definition. For materials not assigned a (+) sign in Column 1 of the HMT, transport classification decisions must utilize the criteria described in § 173.132 of the HMR and Chapter 2 of the IMDG Code, the ICAO Technical Instructions, and the UN Model Regulations.

Q15. Paragraph 2.2.61.1.14 of the European Agreement Concerning the International Carriage of Dangerous Goods by Road (ADR) includes a provision that exempts certain substances, mixtures and solutions from consideration as a Division 6.1 (Toxic) material. You ask whether this rationale is appropriate for the classification of methanol mixtures or solutions.

A15. Paragraph 2.2.61.1.14 of the ADR references two European Council directives. It is the opinion of this Office that provided those directives specifically address methanol mixtures and solutions it may be appropriate to utilize these directives in making classification decisions for transport between ADR contracting parties. However, the U.S. is not a contracting party to the ADR and we recommend directing this question to an appropriate ADR contracting party. A List of Competent Authorities for the application of ADR is available through the following URL: http://www.unece.org/trans/danger/publi/adr/country-info_e.html (last visited May 16, 2019).

Q16. You ask whether there have been any proposals to provide a similar reference in the GHS or the UN Model Regulations.

A16. We are not aware of any proposals to extend references to these European Council Directives to the GHS or the UN Model Regulations.

Q17. In letter of interpretation (LOI) 04-0204 PHMSA agreed that the concentration of methanol in various mixtures described in LOI 04-0134 was sufficiently diluted such that the mixture posed no toxicity hazard to humans. You ask what was the methanol concentration in the product discussed in LOI 04-0134.

A17. The product described in LOI 04-0134 contains various concentrations of hydrogen peroxide (20% – 39%), methanol (4% – 13%), and water (48% – 76%).

Q18. You ask what was the rationale for agreeing that the mixture described in LOI 04 0134 did not pose a hazard to humans.

A18. The review of the mixtures described in LOI 04-0134 (i.e., that they did not pose a hazard to humans) was based on our assessment of the information provided for that product at that time.

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

Sincerely,

Shane C. Kelley
Director, Standards and Rulemaking Division

173.132(a)(1) - (c), 173.132, 173.132(a), 172.101(b)(1), 172.101(c)(10),

Regulation Sections

Section Subject
172.101 Purpose and use of hazardous materials table
173.132 Class 6, Division 6.1-Definitions