DEPARTMENT OF HEALTH & HUMAN SERVICES  Public Health Service 
= .  
Food and Drug Adrnmistrat~on 
#16  2 1  (ge6  8757 Georgia Avenue 
Sdver Sprmg MD 209 10 
TO:  ALL  MANUFACTURERS,  IMPORTERS  AND  POTENTIAL MANUFACTURERS  OF 
SUNLAMP  PRODUCTS. 
SUBJECT:  POLICY ON MAXIMUM  TIMER  INTERVAL AND  EXPOSURE  SCHEDULE  FOR 
SUNLAMP  PRODUCTS. 
BACKGROUND: 
The  amended  performance  standard  for sunlamp products  (21  CFR  1040.29)  was 
published  in the  September 6,  1985 issue of  the Federal  Register  and  w i l l  
become  effective September 8,  1986.  Any sunlamp  product  manufactured  on  or 
after that date must  comply  with  the amended  standard. 
The  ten (10) minute  maximum  timer  interval requirement  was  removed 
from  the original performance  standard since there are newer  sunlamp 
products  on the market  for which  ten (10) minutes  is not  appropriate. 
The maximum  timer  interval now  depends on  the intensity and  spectral 
distribution of  ultraviolet  (W)r adiation  emission of  each individual 
model  of  sunlamp  product  and must  not  exceed  the maximum  recommended 
exposure time  provided  on  the  required  product  warning  label.  Therefore, 
sunlamp product manufacturers  must  develop an exposure  schedule and 
establish the maximum  recommended  exposure  tlme  (and  therefore  the 
maximum  timer interval)  based  on  the characteristics of their particular 
products. 
The  intended purposes  of  a  sunlamp product  timer are to provide 
for reliable control of  exposures  and  to l i m i t  acute (and  delayed) damage 
from unintentionally long exposures.  However,  the maximum  timer  setting; 
should also allow for selection of  exposure times needed to build up  and 
maintain  a  tan.  The maxlmurn  timer interval is in no way  to be considered 
as a safe limit;  all ultraviolet radiation is potentially hazardous. 
The standard requires the manufacturer  to provide an exposure schedule 
in the product warning  label.  The  purpose of  the  exposure schedule 
is to allow a person  to gradually build-up  skin pigmentation  and  to 
maintain a  tan while controlling the risk of  acute injury and delayed 
adverse effects.  Since the W radiation dose  that  causes a  barely 
discernible pink coloration (minimal erythema1 dose or MED)  is not  the same 
for different skin types,  the exposure schedule for first time users w i l l  
depend  on the skin type of  the user.  Furthermore,  suberythemogenic doses 
of  W radiation received  at 24 hours intervals initially lead to lowering; 
of  the erythema  and  tanning thresholds.  Therefore,  the exposure schedule 
and maximum  recommended  exposure time should  be  constrained by  the 
potential for erythema as well as  the quantity of  radiation necessary to 
achieve and maintain a  tan. 
POLICY : 
The  Center  for Devices and Radiological Health  (CDRH)  w i l l  use the 
following criteria to evaluate the adequacy of  the exposure schedule and 
the recommended  maximum  exposure time (and  therefore the maximum  timer 
interval):  Page 2 
1)  The maximum recommended exposure time (and maximum timer 
interval) must not exceed a value which will result in an exposure 
of four (4) times the minimal erythema dose (MED) for untanned 
Type I1 skin (always burns, then tans slightly).  This is based on 
the CDRH Erythema Action Spectrum [proposed action spectrum of 
Commission Internationale de L'Eclairage (CIE) modified by CDRHI. 
See Appendix A for the action spectrum and weighting factors and 
equations needed to derive it. 
The formula for determining the recommended maximum exposure  . 
time,"T " in seconds is : 
e 
2 
Te = 62451~~ where Standard MED = 1565lM  at 296nm 
vi 
= weighting factor 
CViRi 
Ri = irradiance in W/M 2 
2) The recommended maximum exposure time must not exceed a value 
which will result in an exposure of four (4) times the minimal 
melanogenic dose (MMD) for untanned Type I1 skin. This is 
based on the melanogenic action spectrum developed by Parrish 
et a1 (1982).  See Appendix B for this action spectrum. 
The formula for determining the recommended maximum exposure time, 
"T~"in  seconds is : 
2 
where standard MMD  = 459J/M  at 296nm 
J~ = weighting factor 
tRi = irradiance in W/M 2 
3) The recommended exposure schedule should provide for exposures 
of no more than 0.75 MED three times the first week, gradually 
increasing the exposure the following weeks until maximum tanning 
has occurred (approximate,ly four weeks total) and then provide for 
maintenance of a tan by biweekly or weekly exposures of up to 
four(4)  MEDs or four(4)  MMDs, whichever is less. 
CDRB believes that the above criteria balances the need to limit acute (and 
delayed) damages from unintentionally long exposure and the need to provide 
for single exposure durations adequate to achieve and maintain a tan. 
Walter E.  Gundaker, Director 
Office of Compliance 
Center for De&es  and 
Radiological Health 
Appendices  Appendix A 
(page 1) 
L 
W E I G H T I N G   F A C T O R S   F O R   E R Y T H E M A ,   V f  
n 
Wavelength (nm) 
t 
The e.q u.a ti.o ns.   describing the curve are:  Appendix A 
[DATA]GIELYTLE  ERYTHEMA. Vi 
CIE ACTION SPECTRUM MODIFIED BY LYTLE (CDRH) NORMALIZED TO 1 AT 
READING 
1 
1 
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I 
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.7691 
5916 
.4U  + WAVELENGTH (nm) 
The MMD  as function of wavelength has bean interpolated 
(using log MMD)  fromrthe action spectrum tor melanogenesis 
of type 11 skin (~arrishe t a1 1982)  Appendix B 
(page 2) 
TYPE I1  SKIN  1982