December 9, 2025

Kenneth M. Brown
Consolidated Nuclear Security, LLC
301 Bear Creek Rd.
P.O. Box 2009
Oak Ridge, TN 37831-8014

Dear Mr. Brown:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA) regarding the recordkeeping regulation contained in 29 CFR Part 1904 - Recording and Reporting Occupational Injuries and Illnesses. Specifically, you ask several questions concerning whether injuries in the workplace resulting from the use of personal rechargeable lithium-ion batteries are work-related for purposes of OSHA recordkeeping.

Scenario: In your letter, you describe a scenario in which employees bring rechargeable lithium-ion batteries from home to the workplace for use in e-cigarettes, and that are not used in any equipment or device related to employee work duties. You also state that, in this scenario, the battery terminals are unprotected and the employee or employees improperly carry these batteries in their pants pocket, a fire is sparked by the batteries, and that the fire results in employee injury.

Question 1: Does the exception to work-relatedness in 29 CFR 1904.5(b)(3) apply to the scenario above because it is not obvious whether the precipitating event occurred in the work environment or occurred away from work?

Response: No, section 1904.5(b)(3) of OSHA's recordkeeping regulation does not apply in this scenario, assuming that the employee was at your workplace during assigned work hours and present as a condition of employment.

OSHA's recordkeeping regulation at 29 CFR 1904.5(a) states, the employer "must consider an injury or illness to be work-related if an event or exposure in the work environment either caused or contributed to the resulting condition or significantly aggravated a pre-existing injury or illness. Work-relatedness is presumed for injuries and illnesses resulting from events or exposures occurring in the work environment, unless an exception in § 1904.5(b)(2) specifically applies." Section 1904.5(b)(1) defines the work environment as "the establishment and other locations where one or more employees are working or are present as a condition of their employment."

OSHA's approach to work-relationship in the recordkeeping regulation reflects two important principles. The first is that work need only be a causal factor for an injury or illness to be work-related. The regulation requires neither precise quantification of the occupational cause, nor an assessment of the relative weight of occupational and non-occupational causal factors. If work is a tangible, discernible causal factor, the injury or illness is work-related. The second principle is that a "geographic presumption" applies for injuries and illnesses caused by events or exposures that occur in the work environment. These injuries and illnesses must be considered work-related unless an exception to the presumption in section 1904.5(b)(2) specifically applies. Accordingly, the presumption encompasses cases in which an injury or illness results from an event at work that is outside the employer's control, such as a lightning strike, or involves activities that occur at work but that are not directly related to production, such as horseplay. See, the preamble to OSHA's January 19, 2001, Occupational Injury and Illness Recording and Reporting Requirements final rule, published in the Federal Register at 66 FR 5916, 5929. See also, e.g., OSHA's May 17, 2023, letter of interpretation to Mr. Travis Vance.

In addition, OSHA recognizes that injury and illness rates do not necessarily indicate an employer's lack of interest in safety and health. Both the Note to Subpart A of the recordkeeping regulation (29 CFR §1904.0) and the Overview to OSHA Form 300, Log of Work-Related Injuries and Illnesses ( http://osha.gov/recordkeeping/new-osha300form1-1-04.pdf) expressly state that recording a case does not indicate that an employer or employee was at fault or that an OSHA standard was violated.

Section 1904.5(b)(3) addresses the determination of work-relatedness only under circumstances "when it is not obvious whether the precipitating event or exposure occurred in the work environment or occurred away from work." In these situations, the regulation requires the employer to evaluate the employee's work duties and environment to decide whether it is more likely than not that one or more events or exposures in the work environment either caused or contributed to the resulting condition or significantly aggravated a pre-existing injury or illness.

Based on the scenario in your letter, the event that caused the injury to an employee is the fire that occurred at the workplace. Assuming that, at the time of the injury, if the employee was present in the worksite as a condition of their employment, it is "obvious" that the event occurred in the work environment and section 1904.5(b)(3) would not apply. In such cases, the injury must be considered work-related unless an exception in section 1904.5(b)(2) specifically applies. With regard to the improper carrying of lithium-ion batteries, the nature of the activity which the employee engaged in at the time of the event or exposure, the degree of employer control over the employee's activity, the preventability of the incident or the concept of fault do not affect the determination of work relationship.

Question 2: In the above scenario, is the precipitating event the improper carrying of the lithium-ion batteries, or is the precipitating event the fire?

Response: In the above scenario, the precipitating event is the fire in the workplace that injured the employee. In other words, the fire was the identifiable event that the burn injury resulted from. See OSHA's discussion of precipitating events in the preamble to the 2001 final rule at 66 FR at 5959. However, as previously discussed, section 1904.5(b)(3) is inapplicable in your scenario.

Question 3: Would the exception to work-relatedness at section1904.5(b)(2)(iv) apply in this scenario because the injury is solely the result of an employee bringing something personal on-site for the employee's personal use?

Response: No, the exception in Section 1904.5(b)(2)(iv) related to eating, drinking, or preparing food or drink would not apply to the scenario you describe.

Section 1904.5(b)(2)(iv) provides that injuries and illnesses will not be considered work-related if they are solely the result of an employee eating, drinking, or preparing food or drink for personal consumption (whether bought on the premises or brought in). The injury described in your letter does not fall within the exception in section 1904.5(b)(2)(iv) because, at the time of the injury, the employee was not eating, drinking or preparing food or drink for personal consumption.

In the preamble to the 2001 recordkeeping final rule, OSHA made clear that the eight exceptions listed in section 1904.5(b)(2) are the only exceptions permitted by the regulation to the geographic presumption set forth in section 1904.5(a). See, 66 FR at 5950. As such, OSHA interprets the exceptions listed in section 1904.5(b)(2) narrowly and the exceptions are applied to a given situation only when all conditions within a specific exception are met.

In addition, the issue of whether to record injuries and illnesses resulting from employees conducting personal tasks in the work environment was directly addressed by OSHA in the 2001 rulemaking. After careful consideration of the rulemaking record, OSHA concluded that it would be difficult in many cases for employers to distinguish between work activities and personal activities that occurred during the workday, and that the nature of the activity the employee was engaged in at the time of the event or exposure is not relevant in determining work-relatedness, except in those limited circumstances addressed by the exceptions in section 1904.5(b)(2). See, 66 FR at 5954. Accordingly, the recordkeeping regulation contains no general exception for purposes of determining work-relatedness for cases involving employees engaged in purely personal tasks.

Finally, note that the recordkeeping regulation does include a specific exception at section 1904.5(b)(2)(v) that allows employers to exclude injuries and illnesses that are solely the result of an employee doing personal tasks unrelated to their employment at the establishment when these tasks are conducted outside of the employee's assigned working hours. For purposes of the exception in section 1904.5(b)(2)(v), "assigned working hours" means those hours the employee is actually expected to work, including overtime, and "personal tasks" are those tasks that are unrelated to the employee's job. See, OSHA's Frequently Asked Question (FAQ) 5-4 and 5-5. Based on the scenario you describe, there is no indication that the injured employee was either carrying or using lithium batteries in the work environment outside assigned working hours. As a result, the exception in section 1904.5(b)(2)(v) would not apply to your scenario.

Question 4: Does the personal grooming exception in section 1904.5(b)(2)(vi) apply under the facts described above?

Response: No. The exception in section 1904.5(b)(2)(vi) related to personal grooming also would not apply to the scenario you describe. Section 1904.5(b)(2)(vi) provides that a case will not be considered work-related if the injury or illness is solely the result of personal grooming, self-medication for a non-work-related condition, or is intentionally self-inflicted. This exception allows the employer to exclude cases related to personal hygiene, self-administered medications and intentional self-inflicted injuries, such as attempted suicide. For example, a burn injury from a hair dryer used at work to dry the employee's hair would not be work-related. Similarly, a negative reaction to a medication brought from home by the employee to treat a non-work condition would not be considered a work-related illness, even though it first manifested at work. See, 66 FR at 5951.

A burn injury resulting from carrying a lithium-ion battery for purposes of e-cigarette use in the work environment does not fall within the exception in section 1904.5(b)(2)(vi) because it does not involve personal grooming, self-medication for a non-work-related condition, or an intentionally self-inflicted injury. Again, as noted above, the eight exceptions listed in section 1904.5(b)(2) are the only exceptions to the presumption of work-relatedness in section 1904.5(a) and, in order for a specific exception to apply, the case must meet all conditions within that exception.

Question 5: Does it make any difference if the injury is caused (or was contributed to) by the lithium­ ion battery being co-mingled with an employer-provided item, such as a metallic key used at work?

Response: No. For reasons described above, none of the exceptions to work-relatedness in section 1904.5(b)(2) apply to the scenario you describe. Therefore, for purposes of determining work-relatedness, it makes no difference if the employee's injury was caused by the lithium-ion battery being co-mingled with an employer provided item used at work.

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.

Sincerely,

Lee Anne Jillings, Director
Directorate of Technical Support and Emergency Management