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. Drometrizole trisiloxane (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 a physical Sunscreen
      1. Apply Zinc Oxide or Titanium Dioxide containing Sunscreen for maximal protection
  9. Replace old Sunscreens
    1. Changed colors
    2. Significantly past their expiration dates (esp. if exposed to Temperature extremes)
  10. Protective Clothing
    1. Covering skin with Ultraviolet Protection Factor (UPF) Clothing also offers sun 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
  3. Absorption
    1. None of the physical Sunscreens are absorbed through the skin
    2. Some of the chemical Sunscreens may be absorbed through the skin
      1. No known related safety concerns, but further research is ongoing (see link below)
      2. Known risk of Sunburn and skin cancer outweighs the potential risk of Sunscreen aborption

VIII. Drug Interactions

  1. Apply Sunscreen at least 15 to 30 minutes after applying Topical Medications

IX. Resources

  1. FDA Consumer update on Sunscreens and possible absorption
    1. https://www.fda.gov/news-events/fda-voices/shedding-more-light-sunscreen-absorption

X. References

  1. (2020) Presc Lett 27(7): 41
  2. (2018) Presc Lett 25(7): 39
  3. (2013) Presc Lett 20(7): 41-2
  4. Potera (1997) Physician and Sports Med 25(5):117-20
  5. (1999) Med Lett Drugs Ther, 41(1052): 43-4 [PubMed]
  6. Wentzell (1996) Am Fam Physician 53(5):1713-19 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies

Cost: Medications

zinc oxide (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing)
ZINC OXIDE 20% OINTMENT Generic OTC $0.06 per gram

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

Ontology: Zinc Oxide (C0043491)

Definition (NCI_NCI-GLOSS) A compound that may enhance immune function, especially when administered by inhalation.
Definition (MSH) A mild astringent and topical protectant with some antiseptic action. It is also used in bandages, pastes, ointments, dental cements, and as a sunblock.
Concepts Pharmacologic Substance (T121) , Inorganic Chemical (T197)
MSH D015034
SnomedCT 332177006, 398971002, 42841002
English Lassar Paste, Lassar's Paste, Lassars Paste, Oxide, Zinc, Paste, Lassar's, Zinc Oxide, Zinc oxide (ZnO), C.I. Pigment White 4, Lassar's paste, zinc oxide, mineral supplements zinc oxide, zinc oxide (medication), sun screens zinc oxide, sunscreen with zinc oxide (medication), sunscreen with zinc oxide, ZINC OXIDE, Zinc Oxide [Chemical/Ingredient], lassar's paste, oxide zinc, as zinc oxide, ZINC Oxide, Zinc oxide, Zinc oxide (product), Zinc oxide (substance), ZnO, ZINC (AS OXIDE)
French Oxyde de zinc
Swedish Zinkoxid
Czech oxid zinečnatý
Finnish Sinkkioksidi
Spanish Óxido de Zinc, Óxido de Cinc, óxido de cinc (producto), óxido de cinc (sustancia), óxido de cinc, óxido de zinc
Italian Pasta di Lassar, Ossido di zinco
Polish Biel cynkowa, Tlenek cynkowy
Japanese 酸化亜鉛, 亜鉛華
Norwegian Sinkoksyd
German Zinkoxid
Portuguese Óxido de Zinco

Ontology: Octinoxate (C0046100)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C118580
SnomedCT 12695000, 256173002
English 2-Ethylhexyl-p-methoxycinnamat, octyl-methoxycinnamate, Octinoxate, octylmethoxycinnamate, octylmethoxycinnamate [Chemical/Ingredient], OCTINOXATE, octinoxate, octyl methoxycinnamate, Octyl methoxycinnamate (substance), Octyl methoxycinnamate, 2-Ethylhexyl-p-methoxycinnamate, 2-Ethylhexyl-p-methoxycinnamate (substance), OMC cinnamate, OCTYL METHOXYCINNAMATE, 2-ethylhexyl-4-methoxycinnamate, 2-ethylhexyl-p-methoxycinnamate
Spanish octilmetoxicinamato, octilmetoxicinamato (sustancia), 2-etilhexil-p-metoxicinamato (sustancia), 2-etilhexil-p-metoxicinamato

Ontology: oxybenzone (C0069803)

Definition (NCI) A benzophenone derivative used as a sunscreen agent. Oxybenzone absorbs UVB and UVA II rays, resulting in a photochemical excitation and absorption of energy. Upon return to ground state, the absorbed energy results in emission of longer wavelength radiation and decreased skin penetration of radiation which reduces the risk of DNA damage.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C005290
SnomedCT 256175009, 256181001, 255934009, 255882004, 72179002
English 2-hydroxy-4-methoxybenzophenone, oxybenzone, benzophenone-3, 2-Hydroxy-4-methoxy-benzophenone, 2-Hydroxy-4-methoxybenzophenon, 2-OH-4-methoxy-benzophenone, Anuvex, Benzophenone-3, 2-Hydroxy-4-methoxybenzophenone,[2-Hydroxy-4-methoxyphenyl]phenylmethanone, HMBP cpd, oxybenzone [Chemical/Ingredient], OXYBENZONE, benzophenone 3, Oxybenzone, 2-Hydroxy-4-methoxybenzophenone, Oxybenzone (substance), Oxybenzone [dup] (substance), BENZOPHENONE-3
Spanish oxibenzona (sustancia), oxibenzona

Ontology: titanium dioxide (C0076733)

Concepts Pharmacologic Substance (T121) , Inorganic Chemical (T197)
MSH C009495
SnomedCT 432929006, 62036000
English titanium dioxide, titanium oxide, Titanium dioxide (product), Pigment White 6, Titanium White, Titanium(IV) Oxide, titanium dioxide [Chemical/Ingredient], TITANIUM DIOXIDE, Titanium Dioxide, dioxide titanium, titanium dioxde, TITANIUM dioxide, Titanium dioxide, Titanium dioxide (substance)
Spanish dióxido de titanio (producto), dióxido de titanio (sustancia), dióxido de titanio

Ontology: avobenzone (C0097513)

Definition (NCI) A sunscreen blocker. Avobenzone is a topical, broad range UV protector and blocks UVA I, UVA II, and UVB wavelengths, thereby limiting the impact of UV rays on skin. (NCI05)
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C049935
SnomedCT 256171000, 422621002
English 4-tert-butyl-4'-methoxydibenzoylmethane, avobenzone, 4-tert-But-4'-meth-dibenzlmete, Avobenzone (Obsolete), 1-(4-(1,1-Dimethylethyl)phenyl)-3-(4-methoxyphenyl)-1,3-propanedione, 1-(p-tert-Butylphenyl)-3-(p-methoxyphenyl)-1,3-propanedione, Avobenzone, Avobenzone (product), 4-tert-butyl-4'-methoxydibenzoylmethane [Chemical/Ingredient], AVOBENZONE, Butyl methoxydibenzoylmethane, 4-tertiary-Butyl-4'-methoxy-dibenzoylmethane, 4-tertiary-Butyl-4'-methoxy-dibenzoylmethane (substance)
Spanish avobenzona (producto), avobenzona, 4-terbutil-4-metoxi-dibenzoilmetano (sustancia), 4-terbutil-4-metoxi-dibenzoilmetano

Ontology: meradimate (C0304629)

Concepts Organic Chemical (T109)
MSH C413549
SnomedCT 46491005
English meradimate, MERADIMATE, Meradimate, Cyclohexanol, 5-Methyl-2-(1-Methylethyl)-, 2-Aminobenzoate, Menthyl Anthranilate, Anthranilic Acid, P-Menth-3-yl Ester, menthyl anthranilate, Menthyl anthranilate, Menthyl anthranilate (substance)
Spanish mentilantranilato (sustancia), mentilantranilato

Ontology: Sun protection factor (C0796617)

Definition (MSH) A measure of relative protection provided by SUNSCREENING AGENTS against burns due to ultraviolet (UV) radiation from a light source.
Definition (NCI_NCI-GLOSS) A scale for rating the level of sunburn protection in sunscreen products. The higher the sun protection factor, the more sunburn protection it gives. Sunscreens with a value of 2 through 11 give minimal protection against sunburns. Sunscreens with a value of 12 through 29 give moderate protection. Sun protection factors of 30 or higher give high protection against sunburn.
Concepts Quantitative Concept (T081)
MSH D059405
English Sun protection factor, spf, sun protection factor (SPF), Factors, Sun Protection, Sun Protection Factor, Sun Protection Factors, Factor, Sun Protection, Protection Factor, Sun, Protection Factors, Sun, sun protection factor, SPF
French Facteur de protection solaire, Indice de protection solaire
Portuguese Fator de Proteção Solar
Spanish Factor de Protección Solar
Czech ochranný sluneční faktor, SPF
Polish Czynnik ochrony przeciwsłonecznej, Czynnik SPF
Italian Fattore di protezione solare, Indice di protezione solare
German Lichtschutzfaktor
Norwegian Solbeskyttelsesfaktor, Solfaktor

Ontology: drometrizole (C0910661)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH C401764
English drometrizole, Drometrizole, DROMETRIZOLE