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Interpretation Response #18-0087

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

Interpretation Response Details

Response Publish Date:

Company Name: Scarpa Consultants

Individual Name: Nicholas Scarpa, Ph.D.

Location State: NJ Country: US

View the Interpretation Document

Response text:

February 4, 2019

Nicholas Scarpa, Ph.D.
Scarpa Consultants
8 Troon Drive
Fredon, NJ 07860

Reference No. 18-0087

Dear Mr. Scarpa:

This letter is in response to your June 7, July 6, July 17, and August 30, 2018, emails and attachments on behalf of your client, INEOS Paraform GmbH and Company KG (INEOS Paraform, also described in the documents as "Company B") of Mainz, Germany. Your client requests clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the classification of Granuform® 91 and Granuform® 96, materials that contain 91 and 96 percent "UN2213, Paraformaldehyde, Division 4.1 (flammable solid), Packing Group (PG) III," respectively. Specifically, you ask if materials that contain less than 18 parts per million (ppm) of sodium and less than 100 ppm of alkali metal ions and/or other metal ions as impurities do not meet the definition of a Division 4.1 (flammable solid) material as defined in § 173.124(a) of the HMR.

You enclosed several documents and test reports listed in the attachment to this letter but ask that we limit our response to two INEOS Paraform products: Paraformaldehyde B-1 (91%) and B-2 (96%). We have paraphrased the information on these materials that you and your client provided in the table below.


Ref. No.Substance Name1
(Trade Name:
Alkali Metal Ion &
Other Content
Sample Test
6.dParaformaldehyde B-1 (91%)
(<2 ppm Na+)
Performed by Laus
(flame died)
N/ASodium content <2 ppm, <5 ppm other alkali metal ions, 2 other metal ions found in concentrations of 7 and 9 ppm, respectively, in a screening test on 36 different metal elements by ICP, <300 ppm Formic acidSample when heated with a gas burner melted forming a liquid, the liquid started to boil and boiling spot burned with a flame. The flame died on its own when no boiling test item was present.NOT to be classified as Division 4.1
B-2 (96%)
(5 ppm Na+)
(Granuform© 96)
(combustion took > 29 minutes)
N/ASodium content 5 ppm, < 5 ppm other alkali metal ions, 2 other metal ions found in concentrations of 10 and 13 ppm, respectively, in a screening test on 36 different metal elements by ICP, < 300 ppm Formic acidSample was ignited with a flame of a Teclu burner. First melting was observed, then the test item started to burn with 2 seats of fire after 12 seconds. Melting and no formation of smoke were observed. Combustion along 200 mm took 29 minutes and 37 seconds.NOT to be classified as Division 4.1


In accordance with § 173.22, it is the shipper's responsibility to properly classify a hazardous material. This Office does not generally perform that function. However, based on the information you provided, it is the opinion of this Office that the tested materials in Reference Nos. 6.d and 6.e do not exhibit criteria exceeding the limit specified in § 173.124(a)(3)(ii) and, therefore, do not meet the definition of a Division 4.1 readily combustible solid.

I hope this information is helpful. Please contact us if we can be of further assistance.



T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division


1 Paraformaldehyde Assay expressed in available % formaldehyde in brackets.

2 UN Test N.1, section ignition or propagation of combustion within 2 minutes.

Regulation Sections

Section Subject
173.124 Class 4, Divisions 4.1, 4.2 and 4.3-Definitions
173.22 Shipper's responsibility