II. Technique

  1. Use Sunscreen with SPF of 15 or higher
    1. SPF 15-30 is typically sufficient protection
    2. SPF above 50 is unlikely to provide additional benefit
      1. No added protection or prolonged duration of activity
  2. Use Sunscreen that blocks UVA and UVB
    1. Most current Sunscreens block UVB
    2. SPF rating does not apply to UVA
    3. "Broad spectrum" denotes protection for both UVA and UVB
      1. Zinc Oxide
      2. Titanium dioxide
      3. Mexoryl
  3. Shake Sunscreen well before using
  4. Avoid spraying Sunscreen on face
    1. Risk of inhalation
    2. Spray Sunscreen onto hands and then apply to face
  5. Wear Sunscreen on all outdoor daylight exposures
    1. Cloudy days: 80% UV radiation penetrates clouds
    2. Swimming: 50% UV radiation penetrates water
    3. High altitude (UVB increases 8-10% per 1000 feet)
    4. Exposure to snow or water (reflective surface)
  6. Apply 2-3 tablespoons (1 ounce) of Sunscreen for whole body
    1. Do not forget around eyes, ears and mouth
    2. Apply to scalp if bald or hair thinning
  7. Apply Sunscreen 15 minutes before exposure and then every 2 hours (regardless of SPF)
    1. Reapply Sunscreen every 1 hour when sweaty or wet
    2. Water resistant (or water proof) sun screens require the same frequent replacement when wet
  8. Protect babies and children well from Sun Exposure
    1. Keep infants under 6 months in shade or covered
    2. If unable to keep out of sunlight, use zinc oxide or titanium dioxide containing Sunscreen for maximal protection

III. Physiology

  1. Sun Protection Factor (SPF) ratio
    1. Time to produce slight erythema on suncreened skin to
    2. Time to produce same erythema without Sunscreen
  2. SPF Interpretation
    1. "Broad spectrum" denotes protection for both UVA and UVB
    2. SPF gives no information on Ultraviolet A protection
    3. SPF reflects protection from UVB Light
      1. SPF 15 blocks 93% of UVB
      2. SPF 30 blocks 97% of UVB
      3. SPF 50 blocks 98% of UVB

IV. Preparations: Chemical or Organic Sunscreens

  1. Avobenzone (Parsol 1789)
    1. Absorbs both short and long wavelength Ultraviolet A
    2. Does not absorb Ultraviolet B (UVB)
    3. May be degraded by sunlight exposure
  2. Menthyl anthranilate
    1. Absorbs shorter wave length Ultraviolet A
  3. Oxybenzone
    1. Absorbs shorter wave length Ultraviolet A
    2. Banned in Hawaii as of 2021 due to adverse effects to ocean wildlife (coral bleaching, reproduction)
  4. Octinoxate
    1. Absorbs UVB
    2. Banned in Hawaii as of 2021 due to adverse effects to ocean wildlife (coral bleaching, reproduction)

V. Preparations: Physical, Mineral or Inorganic opaque compounds (scatter light)

  1. Types
    1. Titanium dioxide
    2. Zinc oxide
  2. Nanoparticles
    1. All physical Sunscreens are classified as nanoparticle, even if they are advertised as "non-nano"
    2. None of the physical Sunscreens are absorbed through the skin regardless of size (nano or "non-nano")
    3. Nanoparticle Sunscreens are typically easier to apply
    4. Nanoparticle size may have environmental impact, but the effects are not currently known

VI. Efficacy

  1. Reduced with wind, heat, humidity, and altitude
  2. Reduced with poor or inadequate application
    1. Most persons do not apply enough Sunscreen
    2. Multiple layers required to reach listed SPF
  3. Reduces Incidence of Actinic Keratoses
    1. Thompson (1993) N Engl J Med 329:1147 [PubMed]
    2. Naylor (1995) Arch Dermatol 131:170 [PubMed]
  4. Decreases photoaging

VII. Safety

  1. Regular use does not result in Vitamin D Deficiency
  2. Oxybenzone, zinc oxide and titanium dioxide are safe on skin

VIII. Resources

IX. References

  1. (2018) Presc Lett 25(7):39
  2. (2013) Presc Lett 20(7):41-2
  3. Potera (1997) Physician and Sports Med 25(5):117-20
  4. (1999) Med Lett Drugs Ther, 41(1052): 43-4 [PubMed]
  5. Wentzell (1996) Am Fam Physician 53(5):1713-19 [PubMed]

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Ontology: Sunscreening Agents (C0038818)

Definition (NCI_NCI-GLOSS) A substance that helps protect the skin from the sun's harmful rays. Sunscreens reflect, absorb, and scatter both ultraviolet A and B radiation to provide protection against both types of radiation. Using lotions, creams, or gels that contain sunscreens can help protect the skin from premature aging and damage that may lead to skin cancer.
Definition (MSH) Chemical or physical agents that protect the skin from sunburn and erythema by absorbing or blocking ultraviolet radiation.
Definition (CSP) substance applied to the skin to protect it from the effects of sunlight; sunscreens act by absorbing ultraviolet radiation or by reflecting the incident light.
Concepts Substance (T167)
MSH D013473
SnomedCT 256169000, 49663007, 373498003
English Agents, Sunscreening, Sunscreens, Sunscreen agents, sun screens (medication), sun screens, sunscreen agents, sunscreen, Sunscreening Agents, Sunscreen agents (substance), Sunscreen, Sunscreening preparations, Sunscreen agent (product), Sunscreen agent (substance), Sunscreen agent, Sunscreen agent, NOS, Sunscreen, NOS, Sunblock, sunscreens
French Écrans solaires, Protecteurs solaires, Produits antisolaires
Swedish Solskyddsmedel
Czech krémy na opalování, přípravky chránící proti slunci
Finnish Aurinkosuojavoiteet
Polish Środki przeciwsłoneczne, Ekrany przeciwsłoneczne, Substancje chroniące przed słońcem, Środki fotoprotekcyjne, Filtry przeciwsłoneczne
Japanese サンスクリーン, 日焼け止め, 日やけ止め, 日焼け止めクリーム, 遮光剤, サンスクリーン剤, 遮光化粧料
Portuguese Protetores Solares, Agentes Protetores de Raios Solares, Protetores de Raios Solares
Spanish Protectores Solares, pantallas solares (sustancia), pantallas solares, Protectores de Rayos Solares, Agentes Protectores de Rayos Solares, pantalla solar (producto), pantalla solar (sustancia), pantalla solar, sustancia (sustancia), pantalla solar, sustancia, pantalla solar
German Sonnenschutzmittel
Italian Protettivi solari