OSHA issues 4 new interpretive letters

OSHA issued four new letters of interpretation (LOIs) related to occupational noise, respiratory protection, electrical safety, and lead contamination:

• 140 decibels (dB) impact/impulse policy under the noise standard (7/30/2025)
• Whether the respiratory protection medical evaluation may consider factors beyond respirator use (8/1/20205)
• Electrical busway hot swappable plug-in units (8/25/2025)
• Clarification of “as free as practicable” lead contamination on surfaces (9/29/2025)

LOIs do not create further obligations for employers, but instead provide supplementary guidance explaining how a standard, regulation, and/or statute applies to a particular workplace situation or hazardous condition. OSHA may also use LOIs to further explain its compliance directives. As the agency’s regulations often lag years or even decades behind advances in technology, equipment, machinery, and work practices, LOIs also can help bridge those gaps.