§ 1904.6 Determination of new cases.
Basic requirement. You must consider an injury or illness to be a “new case” if:
The employee has not previously experienced a recorded injury or illness of the same type that affects the same part of the body, or
The employee previously experienced a recorded injury or illness of the same type that affected the same part of the body but had recovered completely (all signs and symptoms had disappeared) from the previous injury or illness and an event or exposure in the work environment caused the signs or symptoms to reappear.
Implementation —(1) When an employee experiences the signs or symptoms of a chronic work-related illness, do I need to consider each recurrence of signs or symptoms to be a new case? No, for occupational illnesses where the signs or symptoms may recur or continue in the absence of an exposure in the workplace, the case must only be recorded once. Examples may include occupational cancer, asbestosis, byssinosis and silicosis.
When an employee experiences the signs or symptoms of an injury or illness as a result of an event or exposure in the workplace, such as an episode of occupational asthma, must I treat the episode as a new case? Yes, because the episode or recurrence was caused by an event or exposure in the workplace, the incident must be treated as a new case.
May I rely on a physician or other licensed health care professional to determine whether a case is a new case or a recurrence of an old case? You are not required to seek the advice of a physician or other licensed health care professional. However, if you do seek such advice, you must follow the physician or other licensed health care professional's recommendation about whether the case is a new case or a recurrence. If you receive recommendations from two or more physicians or other licensed health care professionals, you must make a decision as to which recommendation is the most authoritative (best documented, best reasoned, or most authoritative), and record the case based upon that recommendation.
Text reproduced verbatim from the eCFR, edition 2026-01-01, retrieved 2026-07-19. A US Government work in the public domain under 17 U.S.C. 105.
4 OSHA interpretations of § 1904.6
How OSHA has applied this section
Letters of Interpretation are OSHA answering specific questions on specific facts. They explain the requirement above but cannot create additional obligations, and a later letter can supersede an earlier one. Newest first.
- 2010-09-24
Clarification on most authoritative when multiple medical opinions are provided.
- 2005-12-21
Determining if an injury is considered a new recordkeeping case based on a recurrence of previously recorded symptoms.
- 2004-01-15
Evaluation of seven scenarios for work-relatedness and recordkeeping requirements.
- 2004-01-13
Determining work-relatedness when the work event or exposure is only one of the discernable causes; not the sole or predominant cause.
Part-level source: eCFR API, Title 29 Part 1904.
Not legal advice. This page republishes 29 CFR Part 1904 as published by the eCFR and explains it. The recordkeeping duty is the employer’s. Where the rule requires judgement, Job13 says so rather than guessing — run your own case through the free check.