Sunscreens

Question 1

under ideal conditions an SPF of 10 means that a person who normally burns in 20 min will burn in
____ min following the application of the sunscreen

Answer 1

200 min. According to:
SPF = burn time with cream/burn time
without cream

Question 2

topical chemical sunscreens. Action

Answer 2

absorbs UV light

Question 3

the topical chemical sunscreens ■ require application at least ____ min prior to exposure, should be reapplied every ____ h (more often
if _____, _____)

Answer 3

■ requires application at least 15-30 min prior to exposure, should be reapplied every 2 h (more often
if sweating, swimming)

Question 4

UVB absorbers:

Answer 4

PABA, salicylates, cinnamates, benzylidene camphor derivatives

Question 5

UVA absorbers

Answer 5

benzophenones, anthranilates, dibenzoylmethanes, benzylidene camphor
derivatives

Question 6

topical physical sunscreens. Action

Answer 6

l: reflects and scatters UV light

Question 7

topical physical sunscreens. Mention them

Answer 7

titanium dioxide, zinc oxide, kaolin, talc, ferric chloride, and melanin

Question 8

topical physical sunscreens. Effectiveness

Answer 8

all are effective against the UVA and UVB spectrum

Question 9

topical physical sunscreens. Pros and cons

Answer 9

less risk of sensitization than chemical sunscreens and waterproof, but may cause folliculitis or
miliaria

Question 10

reactions of sunscreens.

Answer 10

some sunscreen ingredients may cause contact or photocontact allergic reactions, but are uncommon