{"operation":"document","citation":"26-0041","title":"Diablo Canyon Power Plant — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2026-08-19","effective_on":null,"summary":"26-0041 response to Diablo Canyon Power Plant concerning 171.8, 172.704.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-26-0041.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-26-0041.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-26-0041","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-08/260041.pdf","body":"<<<PAGE 1>>>\n\n3/31/26, 10:56 AM USDOT Mail - Fwd: 172.704 Interpretation Request\nLarson, R.\n26-0041\nFwd: 172.704 Interpretation Request\n1 message\nINFOCNTR (PHMSA) <infocntr.infocntr@dot.gov> To: \"Baker, Yul (PHMSA)\" <yul.baker@dot.gov>\nCc: Hazmat Interps <hazmatinterps@dot.gov>\nGood afternoon,\nPlease see the following request for a letter of interpretation. Let us know if you need anything else.\nBest,\nAminah\n---------- Forwarded message ---------\nFrom: Hewitt, Tim (he/him/his) <TNHW@pge.com>\nDate: Mon, Mar 30, 2026 at 11:53 AM\nSubject: 172.704 Interpretation Request\nTo: infocntr@dot.gov <infocntr@dot.gov>\nMon, Mar 30, 2026 at 3:18 PM\nClassification: Internal\nPipeline and Hazardous Materials Safety Administration\nU.S. Department of Transportation\nOffice of Hazardous Materials Standards\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nSubject: Request for Clarification Regarding Software‑Specific Training Requirements Under 49 CFR 172.704\nTo Whom It May Concern,\nDiablo Canyon Power Plant (DCPP), operated by Pacific Gas and Electric Company, is requesting clarification regarding the\napplicability and scope of software‑specific training requirements under 49 CFR 172.704, as referenced in PHMSA correspondence\nNo. 23‑0057 dated September 28, 2023. This request is being made to ensure continued compliance with the Hazardous Materials\nRegulations (HMR) and to establish clear boundaries for training expectations related to software used in hazardous materials\nshipping activities.\nPHMSA’s interpretation in No. 23‑0057 states that hazmat employees must be trained on any software used to perform functions\nsubject to the HMR. While DCPP maintains a robust, procedure‑driven shipping program with documented qualification, oversight,\nand verification, we seek clarification on how PHMSA intends this interpretation to apply to software used primarily for data entry\nwithin a controlled procedural framework.\nContext of Software Use at DCPP\nDCPP utilizes two primary categories of software in support of HMR‑related activities:\n1. Validated Excel‑based calculation tools\nThese spreadsheets contain embedded formulas that perform HMR‑related calculations for simplistic items.\nEnd users do not modify formulas or logic; they only enter data into designated fields.\nThis level of interaction is comparable to using a calculator or other general‑purpose office software.\n2. Vendor Software\nThe vendor software is used to classify material and generate shipping documentation for more complicated or higher\nactivity items.\nhttps://mail.google.com/mail/u/0/?ik=76db1044b4&view=pt&search=all&permthid=thread-f:1861115813067084035&simpl=msg-f:1861115813067084035 1/2\n\n<<<PAGE 2>>>\n\n3/31/26, 10:56 AM USDOT Mail - Fwd: 172.704 Interpretation Request\nUser interaction is limited to following detailed, step‑by‑step procedures (e.g., enter value X, select option Y , verify\nbox Z is checked).\nThe process is fully governed by approved procedures, and personnel qualification includes demonstration of\nproficiency. Personnel receive procedure use and adherence training embedded in many aspects of their reoccurring\ntraining.\nWhen the software is updated, it is verified and validated prior to implementation, and procedures are updated to\nreflect any changes. Procedure changes are communicated to affected plant personnel.\nIn both cases, the software functions as a data‑entry interface, with the regulated decision‑making and compliance determinations\ncontrolled by procedures, not by user discretion. DCPP may also use web browser software to review the HMR to aid with proper\ndecision making and calculator software to perform mathematical HMR functions.\nRequest for Clarification\nTo ensure consistent application of PHMSA’s expectations, DCPP respectfully requests clarification on the following points:\n1. Does PHMSA consider data entry only use of software, where the employee follows detailed procedures and does not modify\nformulas, logic, or regulatory determinations, to require recurring software specific training under 49 CFR 172.704?\n2. If procedures govern the steps performed in the software, does PHMSA consider procedure‑use training to satisfy the intent of\n“training on the software”?\n3. If recurring software specific training is required even when procedures control the process, what criteria should be used to\ndetermine the threshold of software that no longer requires training?\nMany software platforms used during HMR related tasks, such as Microsoft Office applications, calculators, web\nbrowsers, and specialized vendor software, are capable of performing regulated functions depending on configuration\nand use. DCPP seeks clarification on how to determine which software platforms PHMSA considers to require specific\ntraining and which are considered incidental tools that do not require recurring training.\nDCPP is committed to maintaining full compliance with DOT regulations and ensuring that personnel performing HMR related\nfunctions are properly trained and qualified. We believe that clear guidance on the boundaries of software‑specific training\nrequirements will help ensure consistent implementation across the industry and avoid unnecessary or unintended training burdens.\nWe respectfully request a written response to this inquiry. PHMSA’s interpretations are an essential resource for regulated entities, and\nwe appreciate your continued support in helping facilities apply the HMR correctly and consistently.\nIf additional information is needed, please contact me at (805) 556-5034 or timothy.hewitt@pge.com.\nThank you for your time and consideration.\nRegards,\nTimothy Hewitt\nSenior Advising Radiation Protection Engineer\nDiablo Canyon Power Plant\n9 Miles NW Avila Beach\nAvila Beach, CA 93424\nYou can read about PG&E’s data privacy practices at PGE.com/privacy.\nhttps://mail.google.com/mail/u/0/?ik=76db1044b4&view=pt&search=all&permthid=thread-f:1861115813067084035&simpl=msg-f:1861115813067084035 2/2\n\n<<<PAGE 3>>>\n\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nAugust 19, 2026\nTimothy Hewitt\nSenior Advising Radiation Protection Engineer\nDiablo Canyon Power Plant\n9 Miles NW Avila Beach\nAvila Beach, CA 93424\nReference No. 26-0041\nDear Mr. Hewitt:\nThis letter is in response to your March 30, 2026 email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to hazmat employee training.\nSpecifically, you seek clarification on the applicability and scope of software‑specific training\nrequirements under § 172.704, as referenced in a previous Pipeline and Hazardous Materials\nSafety Administration (PHMSA) letter of interpretation (LOI) (Ref. No. 23‑0057).1 You state\nthat it is your understanding that LOI 23-0057 dictates that hazmat employees must be trained on\nany software used to perform functions subject to the HMR. You describe two categories of\nsoftware used at your company: validated Excel-based calculation tools and vendor software\nused for hazard classification and shipping paper generation. You note that in both cases, user\ninteraction is limited to data entry governed by detailed step-by-step procedures, where\ncompliance determinations are controlled by those procedures rather than user discretion. You\nask a series of questions regarding the § 172.704 training requirements.\nWe have paraphrased and answered your questions as follows:\nQ1. Does data entry only use of software—where an employee follows detailed procedures\nand does not modify formulas, logic, or regulatory determinations—require recurring\nsoftware-specific training under § 172.704?\nA1. The answer depends on whether the individual meets the definition of a “hazmat\nemployee” in § 171.8. As clarified in a previous LOI (Ref. No. 16-0136), an individual\nwhose role is strictly limited to transcribing or inputting data—without exercising any\ndiscretion or making regulatory determinations—is generally not considered a hazmat\n1 WMG Inc., Letter of Interpretation Reference Number 23-0057, available at:\nhttps://www.phmsa.dot.gov/regulations/title49/interp/23-0057.\n\n<<<PAGE 4>>>\n\nemployee and is not subject to HMR training requirements.2 However, if an employee\nuses software to perform a regulated function (e.g., classifying hazardous material or\ngenerating a shipping paper) and is responsible for the accuracy of that information, they\nare considered a hazmat employee. In accordance with § 172.704(a)(2), function-specific\ntraining is required for the tasks an employee performs. Lastly, as stated in LOI 23-0057,\nif a hazmat employee uses specific software to meet HMR requirements, they must be\ntrained in how to use that software correctly to ensure the resulting output is compliant.\nQ2. If procedures govern the steps performed in the software, does procedure-use training\nsatisfy the intent of “training on the software” mentioned in LOI 23-0057?\nA2. Yes. For those determined to be hazmat employees, function-specific training required by\n§ 172.704(a)(2) must be tailored to the actual tasks performed by the employee. If the\nsoftware use consists entirely of following a specific, approved procedure that dictates\nevery input and verification step, then documented training on those procedures satisfy\nthe function-specific training requirement for that task.\nQ3. If recurring software-specific training is required even when procedures control the\nprocess, what criteria determine the threshold for software that no longer requires\ntraining?\nA3. Training is required for any tool that is integral to a hazmat employee's performance of a\nregulated function. General-purpose tools like calculators or web browsers used for\nreference generally do not require specific training under § 172.704, provided the\nemployee is already proficient in their basic operation. When a specialized tool (like your\nExcel-based calculation tools or vendor shipping software) is used to automate HMR\ncompliance, the training must be sufficient to ensure the user understands how to input\ndata correctly and recognize if the software is producing an error or an illogical result.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nAlexander Wolcott\nActing Chief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n2 DuPont Corporation Center for Safety, Health, and Environment (SHE), Letter of Interpretation Reference Number\n16-0136, available at: https://www.phmsa.dot.gov/regulations/title49/interp/16-0136.","truncated":false,"body_characters":10556}