Modifies provisions relating to workers' compensation

SB 865 revises Missouri's workers' compensation law to narrow eligibility for benefits. It redefines "employee" to exclude certain business owners, religious organization volunteers, and minors working illegally, while requiring work to be a "substantial factor" in causing injury - excluding cases where work was merely a "triggering factor." The bill explicitly excludes most cardiovascular diseases, commute injuries, and non-specific occupational illnesses from coverage, listing only 9 toxic exposure diseases (like mesothelioma) as compensable. These changes aim to restrict claims by tightening definitions of work-related injuries and disabilities under the law.