Frequently asked questions

What’s the difference between UVA and UVB light? Which causes cancer and which causes aging?

Although UVA and UVB differ in how they affect the skin, they can both do harm. Overexposure to UVA and UVB damages the DNA in skin cells which can produce mutations that can lead to skin cancer as well as premature aging. UVA has a longer wavelength and is associated with skin Aging. Exposure to UVA can also cause the skin to tan or burn. UVA radiation contributes to the development of skin cancer. UVA is connected to the “Broad-Spectrum Protection” you see on the labels of sunscreen products. Original sunscreens only protected against UVB, but once it was understood how dangerous UVA rays were, sunscreen manufacturers began adding ingredients to protect you from both UVA and UVB. UVA rays penetrate your skin more deeply than UVB. Exposure causes damage to the DNA in cells on the innermost part of your top layer of skin, where most skin cancers occur. UVB Has a shorter wavelength than UVA and is associated with skin Burning. UVB penetrates and damages the outermost layers of your skin and overexposure causes suntan, sunburn and, in some instances, blistering. UVB is connected to the Sun Protection Factor (SPF) on sunscreen product labels. The SPF number tells you how long the sun’s harmful UV radiation would take to redden your skin when using that product compared to the time without any product. UVB can damage your skin throughout the year and is especially dangerous at high altitudes and on reflective surfaces (I.e. snow or ice).

What type of sunscreen is best: UV Absorbing (chemical) Sunscreen or UV Reflecting (mineral) Sunscreen?

UV Absorbing, or chemical, sunscreens work like a sponge and absorb the sun’s UV. They contain one or more of the following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate. UV absorbing sunscreens tend to be easier to rub into your skin without leaving a white residue. UV Reflectiive, or mineral, sunscreens act like a shield. They sit on the surface of your skin and deflect the sun’s rays. They contain the active ingredients titanium dioxide, zinc oxide, or both. If you have sensitive skin, opt for this type of sunscreen. Regardless of which sunscreen you choose, the best sunscreen is the sunscreen that you actually use! What matters is ensuring broad spectrum protection (from both UVA and UVB rays), an SPF of 30 or higher and water resistance.

I’ve heard some ingredients of chemical sunscreen can be bad for you, is this true?

Further research is needed. According to the American Academy of Dermatology, "A recent study by the FDA looked at four sunscreen ingredients and concluded that absorption of these ingredients into the body supported the need for additional safety data. However, the study noted that the data do not conclude that there are any effects on a person’s health and more research would be needed before it can be determined. Importantly, the study authors stated that individuals should continue to use sunscreen."

How much sunscreen should I use and how often do I need to apply it?

Make sure to apply enough sunscreen to cover all exposed areas of the ski n. Most adults need about one ounce of sunscreen (enough to fill a shot glass) to fully cover their body. Remember to protect the tops of your feet, your neck, your ears, and the top of your head. Apply sunscreen to dry skin at least 15 minutes before going outdoors. Skin cancer can also form on the lips. To protect your lips, apply a lip balm or lipstick that contains sunscreen with an SPF of 30 or higher. When outdoors, reapply sunscreen every two hours and after swimming or sweating.

What is SPF and what SPF do I need to use?

Sun Protection Factor (SPF) tells you how long the sun’s UV radiation willl take to burn your skin when using that product compared to the time it will take without the sunscreen. The Colorado Melanoma Foundation recommends using a sunscreen with an SPF of 30 or higher, which can block 97 percent of the sun’s UVB rays. Higher SPF’s block slightly more of the sun’s UVB, but no sunscreen can block 100 percent of the sun’s harmful UVB radiation. High-number SPF’s last the same amount of time as low-number SPFs so make sure to re-apply every 2 hours and after swimming or sweating!

What should I look for when choosing a sunscreen?

Choosing the right sunscreen can help reduce your risk of developing skin cancer and premature aging caused by harmful UV from the sun. The Colorado Melanoma Foundation recommends choosing a sunscreen that states the following on the label: Broad spectrum: "Broad Spectrum" means that the sunscreen can protect your skin from both types of harmful UV rays (UVA and UVB). SPF 30 or higher: Select a sunscreen with an SPF rating of 30 or higher. Water resistant: Look for the words “water resistant”. This tells you that the sunscreen will stay on wet or sweaty skin for a while before you need to reapply. Not all sunscreens offer water resistance so make sure to read your label and apply often.

How do the free skin exams work?

If you or a loved one would like a free skin screening performed by a skin health professional, just visit the Sun Bus at one of its scheduled events and we will sign you up. These free screenings are provided on a first come, first serve basist. Check our Calendar of Events for a detailed list of future event locations and scheduled times a provider will be present.

Where can I find a print out with additional information about The Sun Bus?

The Sun Bus Informational booklet is available for download HERE.

What types of events does The Sun Bus attend?

Prior to COVID-19, The Sun Bus attended large community and state-wide events, fairs, trade shows, and festivals. During the school year, The Sun Bus worked with Colorado public and private schools to provide sun safety education to children at every grade level. The Sun Bus also worked with municipalities and businesses to deliver an inexpensive method to provide free skin cancer screenings to a population of residents or employees. In the age of COVID-19, we have had to change our approach in order to continue providing important sun-safety education and screening to residents in Colorado and beyond. With this in mind, The Sun Bus will begin the 2021 season with a tour of each Epiphany Dermatology location in Arizona, Colorado, New Mexico, and Texas. Check out our Calendar of Events to find the location most convenient for you.

How do I get The Sun Bus to attend my event?

If you are interested in having The Sun Bus attend your event, please complete the Event Suggestion form located on the Calendar of Events page. You can also send a message with your request directly to Our attendance is based on our availability and the Calendar for 2021 is filling up fast! Reach out to see if The Sun Bus is available for your event today!

How do I become a Volunteer Public Educator with The Sun Bus?

If you are interested in joining team Sun Bus by becoming a Volunteer Public Educator, please complete the Volunteer Public Educator Sign-Up.

How do I become a Volunteer Physician with The Sun Bus?

If you are interested in joining team Sun Bus by becoming a Volunteer Physician, please complete the Volunteer Physician Sign-Up.

What are the most common skin cancers?

The three most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma (both are often grouped in nonmelanoma skin cancers) and melanoma. To Learn about each type, click HERE.

What are the warning signs of skin cancer?

Because skin cancers are caused by the uncontrolled growth of skin cells, the first warning sign is usually a visible change in a person's skin. Consult a trained physician immediately if you observe any of the warning signs associated with skin cancer. Click HERE to view the warning signs for basal cell carcinoma, squamous cell carcinoma, and melanoma.

What are the treatments for skin cancer?

Nonmelanoma skin cancers are some of the most easily treatable cancers. When melanoma is caught and treated early (before spreading to the lymph nodes), it is also highly curable. The goal of treatment for skin cancer is to remove all of the cancer. Typically, the first line therapies are surgical; however, non-surgical treatments may be an option in some cases. The type of surgical treatment used depends on the type, size, depth and location of the cancer. In most cases, the procedure is done on an outpatient basis. The most common surgical procedures to remove cancerous areas of the skin are: Mohs micrographic surgery: A "stepwise" excision performed by a dermatologist with special training in the procedure. Thin layers of skin are removed in stages and examined under a microscope for the presence of cancer cells. The process is repeated until no cancer cells remain. Mohs is used for certain types of skin cancer on the head, neck, feet and genitalia. It offers the highest cure rates (up to 99 percent for certain skin cancers) and leads to the best possible cosmetic result. Standard excision: The skin cancer is excised along with a standard amount of normal-appearing skin. This may be used for melanoma and small nonmelanoma skin cancers on the torso and extremities. Curettage and electrodessication: Involves the scraping the cancerous growth with a curette and cauterizing the area to destroy residual tumor and to control bleeding. This may be effective for a subtype of basal cell carcinoma and very early squamous cell carcinoma. Radiation, chemotherapy or immunotherapy may be necessary for advanced cases of skin cancer or when patients are unable to have surgery. Learn about other treatment options and strategies HERE.

Is skin cancer becoming more common? What are some of the risk factors?

According to the American Academy of Dermatology, skin cancer is the most common cancer in the United States with 1 in 5 Americans likely to develop the disease during their lifetime. The most common risk factor for developing skin cancer is exposure to harmful UV radiation from the sun. To learn about the other risk factors for skin cancer, Click Here.

What can we do to protect ourselves from the sun?

Sun exposure can damage your skin during every season. Protect yourself from premature aging and skin cancer by following these Sun Safety Tips.

Myth or Fact? The higher the SPF the better.

SPF (Sun Protection Factor) refers to the ability of sunscreen to protect against UVB radiation. The numbers, however, are not logical and the relationship is not linear (i.e. SPF 30 is not double the protection of SPF 15). SPF 15 protects against 93% of the UVB radiation that hits your skin, SPF 30 protects against 97% of UVB, and SPF 50 blocks out 98% of UVB. If you use products with an SPF greater than 50, you will get a negligible increase in protection from UVB radiation. The Colorado Melanoma Foundation recommends that you use a sunscreen that is at least SPF 30. Don't spend extra money on SPF 50+, because there is not much added protection. It’s also important to make sure that your sunscreen protects against both UVA and UVB radiation. Look on the bottle to make sure it says “broad spectrum” protection against UVA and UVB.

Myth or Fact? You don’t need that much sunscreen to be protected.

Myth! The amount of sunscreen researchers use when studying the product is 2mg of sunscreen for each square centimeter of exposed skin. Think about that for a second… that’s a lot of sunscreen! Most people apply only 25-50% of the recommended amount of sunscreen. A good rule of thumb is the shotglass rule. The amount of sunscreen that fills a shotglass (one ounce, or 30mL) is how much you need to cover the exposed areas of an adult body. Since most bottles of sunscreen are 90-150mL, they should be used up after 3-5 applications of sunscreen. If you put on less sunscreen, you will still get some protection, but you won’t get the full SPF protection that is labeled on the bottle. Sunscreens should last for at least three years – however, if you are using it properly, you shouldn’t have to worry about the expiration date because you will have consumed your bottle before then.

Myth or Fact? I don’t need sunscreen on cloudy days.

Myth! Harmful UV is present on cloudy days and winter days. In fact, up to 80% of harmful UV can still penetrate the skin when it’s cloudy. A better indication of whether or not you need sun protection is to look at the UV index on your local weather report or app. The UV index looks at how much radiation we are actually receiving from the sun. A UV index greater than 3 indicates a moderate risk of harm from unprotected sun exposure. If it is 3 or greater, make sure to put on sunscreen and stay out of the sun between 10am to 4pm, when the UV rays are strongest. If possible, try to plan your outdoor activities before 10am and after 4pm.

Myth or Fact? If I put on sunscreen, I can safely sit in the sunshine.

Myth! Sunscreen is meant to provide protection during periods of exposure to harmful UV. It shouldn’t be used as a way to increase the amount of time you can spend in the sun. Even if you are wearing sunscreen, you should still wear a hat, stay in the shade, wear protective clothing, and take breaks from the sun. Apply sunscreen at least 15 minutes before sun exposure to allow the product to form a protective film on your skin. Reapply every 2 hours and after swimming or sweating – even if iyour sunscreen is labelled water resistant! There are two ways that sunscreens work – by absorbing or reflecting harmful UV. UV reflecting sunscreens (aka physical sunscreens) work by reflecting or blocking UV rays before they reach your skin. UV absorbing sunscreens (aka chemical sunscreens) work by absorbing UV rays so that they can’t damage your cells.

Myth or Fact? Spray on sunscreens are the same as regular sunscreens.

Myth! There are two main concerns with spray on sunscreens: accidentally inhaling or ingesting the products and adequate protection. When we spray sunscreen, the particles are aerosolized and become more likely to be inhaled. There is currently not enough data on whether or not these particles are safe, especially in children. It is possible that they could trigger asthma attacks or allergic reactions and some organizations even recommend avoiding spray on sunscreen in children (unless no other product is available) due to the lack of safety data. The other concern about spray on sunscreens is that it is difficult to tell if you’ve put on enough, possibly resulting in less protection compared to cream sunscreens. How you spray on the sunscreen and environmental factors like the wind can also affect how much sunscreen actually reaches your skin. If you decide to use spray on sunscreen, avoid inhaling it as much as possible. Don’t spray it in enclosed areas, and be aware around open flames because some sprays are flammable. It is best to spray the product onto your hands and then rub it onto your skin, particularly when applying to your face. This reduces inhalation and provides better coverage. Apply a lot because it’s harder to assess coverage with sprays.

Myth or Fact? Some sun is good for me.

Myth! The most significant risk factor for developing skin cancer is exposure to harmful UV radiation from the sun and artificial sources. There is no safe way to tan. Every time you tan, you damage your skin. UV radiation from the sun and artificial sources causes skin cancer and premature aging. It is a known carcinogen, comparable to tobbaco use and exposure to asbestos, so protect yourself!