# General Hydroponics — Hazardous Materials Safety Interpretation **Citation:** 04-0195 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2005-06-13 04-0195 response to General Hydroponics concerning 172.101, 172.102. ## Document text <<>> 400 Seventh Street, S.W. Washington, D.C. 20590 Pipeline and JUN 13 2005 Hazardous Materials Safety Administration Mr. Cal Herrmann ScD Ref No.: 04-0195 Consulting Chemist General Hydroponics P.O. Box 1576 Sebastopol, CA 95473 Dear Mr. Cal Herrmann: This responds to your December 15, 2004 letter requesting clarification of the Hazardous for hydroponic plant growth. Specifically, you ask if the products described in your letter are Materials Regulations (HMR; 49 CFR Parts 171-180) for plant nutrient products that are sold subject to the HMR. You provide the following two product descriptions: 1) Aqueous solution of inorganic minerals containing less than 10% Nitrates. 2) Dry mixtures of inorganic minerals containing calcium nitrate and ammonium nitrate, with less than 10% ammonium nitrate and at least 12% water of crystallization. In accordance with § 173.22 of the HMR, it is the shipper's responsibility to determine the hazard class of a material offered for transportation in commerce. This office does not perform that function. Special Provision 58 (see § 172.102) provides an exception for aqueous solutions of Division 5.1 inorganic solid nitrate substances when the concentration of the substances in solution at the minimum temperature encountered in transport is not greater than 80% of the saturation limit. Your product is not subject to the HMR if it meets Special Provision 58 and does not meet the definition of any other hazard class listed in § 173.2. Special Provision 34 (see § 173.102) provides an exception for commercial grade calcium nitrate fertilizer, when consisting mainly of a double salt (calcium nitrate and ammonium nitrate) containing not more than 10 percent ammonium nitrate and at least 12 percen: water of crystallization. Your product is not subject to the HMR if it meets Special provision 34 and does not meet the definition of an other hazard class listed in § 173.2. I hope this information is helpful. Please contact us if you require additional assistance. Sincerely 172.101 172.102 Office of Hazardous Materials Standards 040195 <<>> Exchenlaub Office of Hazardous Materials Standards, 3172.101 Research and Special Programs Administration, § 172. 102 Attn: DHM10 U.S. Department of Transportation 400 7th Street SW Proper Shipping Name Washington, DC 20590-0001 04-0795 Dec 15, 2004 To whom it may concern: Pursuant to CFR 49 105.20 we are requesting information on applicability of DOT regulations concerning shipping some of plant nutrient products that are sold for hydroponic plant growth. They are individually packaged in 1 to 5 pound or quart to item containers. gallon containers meeting the defined container requirements, and boxes of several Specifically we need to know if we understand correctly as it relates to our products it contain nitrates. We ship products that contain nitrates in two forms. They are: Aqueous solutions of mixtures of inorganic minerals containing less than 10% Nitrates. We think these products could be classified as - Nitrates, Inorganic, under code 58 of 172.102. aqueous solution, n.o.s., and exempt from the 5.1 shipping regulations as defined Dry mixtures of inorganic minerals containing calcium nitrate and ammonium nitrate and with less than 10 percent ammonium nitrate and at least 12% water of calcium nitrate and under code 34 of 172.102 be exempt from 172.101. crystallization. We think that these products could be classified as containing Please advise us if our assumptions are correct or not in this matter. Cal Herrmann ScD Consulting Chemist 707-824-9376 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `5ae644e923542b19427913abbff2ad92808ff44028f20ef4c6c3c104c74ffa5e` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T13:55:01.275Z - Document slug: `phmsa-interpretation-04-0195` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "General Hydroponics" ], "individuals": [ "Mr. Cal Herrmann ScD" ], "refIds": [ "04-0195" ], "catalogDates": [ "2005-06-13" ], "catalogParts": [ 172 ], "catalogRowCount": 2, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/43826" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "172.101", "172.102", "173.22", "173.2", "173.102" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/172101", "https://www.phmsa.dot.gov/regulations/title49/section/172102" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2004/040195.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2004/040195.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2004/040195.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/04-0195-72fe6adbdd.pdf", "pdfArtifactSha256": "4a9f09d9bc4def689d9646dff3a00e7e8c2a19cd7eef484ca73575a15bc6a312", "extractedTextPath": "data/sources/phmsa-interpretations/04-0195-72fe6adbdd.v2.txt", "extractedTextSha256": "3b7350eeae2b8013edbe5ce5da8e908b6d9190adc3b02a25fb88574e872fc191", "pageCount": 2, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```