Health and Halacha

Written by Audrey Siegal on . Posted in Health & Wellness

Ah summer! Although for a while we seemed to be getting a late start this year, the summer sun finally has arrived. No sooner than we finish complaining about the cold start to the season, we will have the opportunity to bemoan the heat and humidity. 


Many of us will meet the steamy Washington landscape head-on and engage in outdoor activities. We know the number one warning that comes with summer is to protect oneself and one’s family from dangerous UVA and UVB rays. Easier said than done.

Today, I want to touch on two aspects of sun protection. First, the basics: what is the best way to have fun this summer and stay as safe as possible? Secondly, how do we protect ourselves halachically on Shabbat, which for many of us, might be the day we are the most exposed.

For a quick overview of Sun Protection 101, I turned to Dr. David Green, a board-certified dermatologist practicing in Bethesda and Annapolis, Maryland. I learned that there are three levels of sun protection, and the very best is avoidance. UVB rays cause the rough spots on the surface of the skin that can lead to skin cancer and UVA rays cause the visible signs of aging. It is best to avoid catching both rays to the extent that you can. We know, however, that the beach, the boardwalk, and boats all beckon and so level two is to wear protective clothing, including hats and even umbrellas. Level three, sunscreen, helps protect exposed areas, including the face, arms, and legs.

There are many choices of sunscreen, but the best ones to apply, according to Dr. Green, are those that have the highest sun protection factor (SPF). SPF is a relative measure of how long a sunscreen will protect you — but onlyfrom the UVB rays from the sun. If you properly apply SPF 50, you will get 1/50 of the amount of exposure to the sun’s UVB rays as you would normally get in the same amount of time if you were not wearing any sunscreen.

How long is that? Well, it depends on your complexion and susceptibility to the sun’s rays. If you would normally develop a sunburn, i.e., redness, after 10 minutes of sun exposure without sunscreen, theoretically, you would be protected for 500 minutes with a SPF 50 sunscreen if properly applied. Remember the word properly— we will come back to that shortly. It is important to understand that SPF rating does not connote any protection against UVA rays from the sun. By using a sunscreen that is labeled broad spectrum, you are also provided with some protection against UVA rays. However, the amount of protection is not well understood. So, don’t be surprised if you develop a sunburn or suntan in spite of properly applying a sunscreen with a high SPF level of protection. The UVA rays also can produce sunburn.

To properly apply sunscreen, you should use a lot and really slather. Generally, dermatologists recommend one to one and a half ounces of a good SPF sun screen for about two hours of outdoor activity. The key is, if you must be out when the sun is strongest, to put on enough sunscreen, reapply and cover up with clothing, hats, and sunglasses to the extent possible. The sun shines through the clouds, so a cloudy day is no protection.

This discussion only “scratches the skin’s surface” and truly needs to be followed up by a conversation with your doctor. It is a good idea to learn as much as you can about best practices and your own personal risk factors, and to keep updated as new products come on the market.

Now, for a quick review of the halachic issues with sun protection on Shabbat.

While normally it does not matter what form of sunscreen you use, on Shabbat, according to halacha, one should use spray. I checked with a local Rabbi who outlined the reasons why:

The general problem that can come up with sunscreen is the problem with all lotions, the prohibition of memareyach (smoothing). Depending on the thickness of a lotion or salve, it could be a biblical prohibition with actual solids (like deodorant sticks) or a rabbinic prohibition with semi-dense solids like hand cream. However, spreading liquids like liquid hand soap or perfume on skin is nota problem. Therefore, the best thing to use is the liquid spray sunscreen.

There could, however, be another halachic problem with the liquid spray which is connected to the scent. There is a rabbinic prohibition to spray a garment with a scent-like perfume. If the sunscreen is scented, then one should make sure to spray on skin and not on clothing.

Once again, I have only given a basic outline of the issues and everyone concerned about the halachic aspects of sunscreen on Shabbat should consult their own rabbi.

Wishing everyone an enjoyable and safe summer!

By Audrey Siegal

 Audrey Siegel is the executive director of Bikur Cholim of Greater Washington. She is a former New Yorker who has enjoyed living in Silver Spring with her family for the past 27 years. Audrey hopes to hike or bike every nature trail in Montgomery County, so wave if you see her along the way.