FDA-sunlamp recommended Maximum Timer Interval And Exposure Schedule: consensus ISO/CIE dose equivalence

Area of Science:

• Dermatology and Photobiology
• Medical Device Regulation
• Public Health

Background:

• Current USFDA sunlamp guidance uses unique erythema action spectrum and timer intervals.
• USFDA/CDRH proposed revisions in 2003 to align with ISO/CIE standards, aiming for biological equivalence.
• Preliminary analyses suggested these revisions could lead to increased UV exposure.

Purpose of the Study:

• To compare current USFDA sunlamp exposure limits with proposed USFDA/CDRH revisions.
• To verify and quantify the erythemal dose equivalence between current and proposed sunlamp exposure policies.
• To propose a revised maximum exposure limit and tanning schedule compatible with existing equipment and standards.

Main Methods:

• Calculated sunlamp maximum exposure times based on current USFDA policy and proposed USFDA/CDRH revisions.
• Utilized 89 UV spectra from U.S. indoor tanning equipment provided by manufacturers.
• Determined CIE effective dose per USFDA maximum recommended exposure time (Te) and compared it to ISO/CIE Standard Erythema Dose (SED).

Main Results:

• The CIE effective dose per Te averaged 456 J(CIE) m(-2) (approx. 4.5 SED) across analyzed tanning equipment.
• The USFDA/CDRH proposed 600 J(CIE) m(-2) maximum exposure exceeds current Te erythemal dose by approximately 33%.
• No analyzed sunlamps exceeded 5 SED, suggesting a revised maximum of 500 J(CIE) m(-2) is feasible.

Conclusions:

• The proposed USFDA/CDRH revisions do not ensure biological equivalence and may increase UV exposure.
• A revised maximum exposure limit of 500 J(CIE) m(-2) is recommended for compatibility with current tanning equipment.
• A phased tanning acclimatization and maintenance schedule, starting at 1 SED and increasing to 5 SED, is proposed as biologically equivalent to current USFDA policy.