March 17, 2021

Mr. Timothy S. Dillon
EHS Staff Manager
Pacific Scientific, Chandler Operations
Pacific Scientific EMC
7073 W. Willis Rd.
Chandler, AZ 85226

Dear Mr. Dillon:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA). This letter constitutes OSHA's interpretation only of the requirements referenced below and may not be applicable to any question not included in your original correspondence. Your inquiry relates to the application and enforcement of OSHA's standards, 29 CFR § 1910.109. Explosives and Blasting Agents and 29 CFR § 1910.119 Process Safety Management of Highly Hazardous Chemicals (PSM), as they apply to articles or devices that the U.S Department of Transportation (USDOT) classifies as "Not in the explosives class."

Background/Scenario: OSHA, at 29 CFR § 1910.109, regulates the manufacture, keeping, having, storage, sale, transportation, and use of explosives, blasting agents, and pyrotechnics. In addition, 29 CFR § 1910.109(k)(2) and (k)(3) require employers manufacturing explosives and/or pyrotechnics to comply witht the PSM standard.

OSHA defines an explosive as "any chemical compound, mixture, or device, the primary or common purpose of which is to function by explosion...unless such compound, mixture, or device is otherwise specifically classified by the U.S Department of Transportation."¹ Explosives also "include all material which is classified as Class A, Class B, and Class C explosives by the U.S Department of Transportation."² OSHA defines pyrotechnics as "any combustible or explosive compositions or manufactured articles designed and prepared for the purpose of producing audible or visible effects which are commonly referred to as fireworks."³

You have stated that since 2011, the USDOT Pipeline and Hazardous Materials Safety Administration (PHMSA) has classified articles that meet specified test criteria as “Excluded from Class 1 (explosives)” or “Not Regulated.” This classification is based on test criteria established and approved by the United Nations Dangerous Goods Council. Based on the characteristics of the material that passes all the specified testing⁴, the articles do not pose the hazards exemplified by explosives.

You also clarified that the articles in question are finished articles that have already been through the manufacturing process. You stated in your telephone conversation with our Directorate of Enforcement Programs staff that USDOT PHMSA has approved independent third party explosive testing laboratories in accordance with 49 CFR § 173.56(b)(1), which requires that new explosives must be examined, classified, and approved.

In your request, you provided a document, which shows that USDOT classified your company’s Guillotine Assembly article as “Not regulated as Class 1 Hazardous Material” in accordance with 49 CFR § 173.56.⁵

Question (paraphrased): Do OSHA’s 29 CFR § 1910.109 and 29 CFR § 1910.119 standards apply to articles or devices that have been approved as either “Not in the explosive class” or “Not regulated as Class 1 Hazardous Material” by the USDOT, or assigned a tentative class under 49 CFR § 173.56(d) as “Not in the explosive class” or “Not regulated as Class 1 Hazardous Material by a testing agency?”

Response: No, OSHA’s Explosives and Blasting Agent and PSM standard do not apply to articles or devices that have been classified by the USDOT as “Not in the Explosive Class,” or “Not regulated as Class 1 Hazardous Material.” The USDOT approval of classification in this case, signifies that the article or device is neither classified by USDOT as an explosive, nor classified as a Class A, Class B, or Class C explosive (current classification: Class 1.1 – 1.4).

However, OSHA does regulate the manufacturing of articles or devices, even those that are classified as “Not in the explosive class,” or “Not regulated as Class 1 Hazardous Material,” which use explosive or pyrotechnic materials, as defined in 29 CFR 1910.109(a)(3), in their manufacturing process. This manufacturing process is a PSM-covered process (29 CFR 1910.119) and is also regulated under OSHA’s Explosives and Blasting Agents standard (29 CFR 1910.109).

As discussed in the Background/Scenario section, the two standards apply to explosives and pyrotechnics. OSHA defines an explosive as “any chemical compound, mixture, or device, the primary or common purpose of which is to function by explosion . . . unless such compound, mixture, or device is otherwise specifically classified by the U.S. Department of Transportation.” Here, the USDOT or a USDOT-approved testing agency has specifically classified the articles as “Not in the explosives class.” This classification means that the substance or article “does not have significant explosive hazard” or that “the effects of explosion are completely confined within the article.”⁶ The articles classified as “Not in the explosive class” are not explosives or pyrotechnics, and the two OSHA standards therefore do not apply.

In circumstances where USDOT has tentatively approved a substance as “Not in the explosive class,” or “Not regulated as Class 1 Hazardous Material,” OSHA will generally not enforce its standards based on this tentative classification unless USDOT later issues a formal approval establishing the classification of the new substance as explosive. If and when this occurs, OSHA will then enforce any applicable provisions of its standards.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA’s interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov. If you have further questions, please contact the Office of Chemical Process Safety and Enforcement Initiatives at (202) 693-2341.

Sincerely,

Patrick J. Kapust, Acting Director
Directorate of Enforcement Programs

¹ 29 CFR § 1910.109(a)(3)
² On January 1, 1991, USDOT changed its explosives classification system names from the Class A, B, and C to Division 1.1 to 1.4. See 49 CFR § 173.53 Provisions for Using Old Classifications of Explosives.
³ 29 CFR § 1910.109(a)(10)
⁴ UN Transport of Dangerous Good, Model Regulations, 20th ed., Section 2.1.3.6.4
⁵ PHMSA Hazardous Materials Approvals Search Page, https://www.phmsa.dot.gov/approvals-and-permits/hazmat/approvals-search/0, Tracking Number: 2015020945.
⁶ 49 CFR § 173.58(a)(6).