SUN PROTECTION

What is SPF?

'Sun Protection Factor' Grades the ability of a sunscreen to filter UV - guide to relative potency. Ratio of UV radiation dose required to produce minimum erythema (MED) on skin that has been protected with the product to the dose required to produce erythema on unprotected skin under same conditions.

Sunscreens - Selection

- A broad-spectrum sunscreen with SPF of 30+ - If water exposure likely, use water-resistant sunscreen - Select formulation that best suits skin type, type of activity etc. - Alcohol-based less sticky, dry faster; may sting sensitive skin - For sensitive skin, use specifically formulated and labelled product

Water resistance testing

- Application of product as for SPF testing. - Immersion in pool - indoors; protected from direct sunlight; pH 6.8-7.2 - Test for protection factor post-immersion - Swimming pool immersion - 23-280c; 20 mins. moderate swimming activity alternating with 5 min. rest period (no towelling-off of test sites) - Spa pool immersion - 330C; subject seated away from direct jets; in each 20 mins., water circulated 16 mins., air-agitated 4 mins.

Sunscreens - Availability

- Listing on the TGA Register of Therapeutic Goods (ARTG) - Approval of active ingredients and maximum permitted concentrations are the responsibility of the TGA. - Compliance with Australian Standard for sunscreen products is a condition of listing - e.g. SPF, waterresistance, labelling

What is meant by 'broad spectrum'?

All sunscreens with an SPF number will filter out UVB - Long known that UVB causes skin cancer Those labelled 'broad-spectrum' also filter UVA. - More recent evidence shows UVA also contributes Broad-spectrum sunscreens usually contain both a physical blocker and a UVB- & UVA-absorbing agent

Sunscreen and babies

Best to keep babies and toddlers out of the sun or well-protected using clothing, hats and shade Only use sunscreen on skin that can't be covered by other methods Some products have 'sensitive skin' versions, which are useful for babies - Test the sunscreen on a small area of the child's skin to make sure there is no reaction

Sun protection strategies - SLIP (1/2)

Clothing protects skin by creating a barrier: - UPF rating indicates the percentage of UV radiation transmitted through unstretched, dry material. - UPF 30 provides good protection; 50+ recommended (absorbs 98% of UV radiation) - Specially designed protective clothing will have UPF rating on tags

Timing and duration of exposure

Danger times for sunburn: - UV radiation most intense 10 am - 2 pm (11 am - 3pm daylight saving time) - In Australia, sunburn can occur in less than 15 minutes on a fine summer day - UV radiation is not related to temperature - people often get burnt on days <300C

Sun protection strategies - SLAP

Hats help protect common sites of skin damage and skin cancer: neck, ears, temples, lips, face and nose Recommended hats (shade whole face, neck, ears and head) - Broad-brimmed hat - brim at least 7.5 cm - Legionnaire hat - side flap and front peak should meet to protect side of face; brim at least 5 cm for pre-school children; 6 cm for primary school and older children - Bucket hat - brim as above

Sun protection strategies - SLIP (2/2)

Materials such as cotton, polyester and nylon have natural UV absorbing properties Weave density - close weave fabric higher UV protection Colour - Darker colours (black, navy, dark red) absorb more strongly than lighter colours and therefore have higher UPF rating Tension - Stretching will decrease UV radiation protection Moisture content - Many fabrics offer lower protection when wet UV absorbers - Clothing can be treated to absorb more UV

Sunscreens - Application

Must be applied liberally (and evenly) to achieve SPF protection claimed on label: - Recommended amount for average adult: - half to one tsp. for the face, neck and ears; - one tsp. for each arm and leg, front of body & back of body • i.e. around 35mL for full body application Apply ~20 minutes before exposure Reapply regularly - at least every 2 hours (sunscreen can be easily wiped or perspired off )

Sunscreens - risks

Regular daily sunscreen use advocated Short-term risks - sensitivity to ingredients - usually local irritation rather than allergy or photosensitivity - allergy to sunscreen agents less common that to other ingredients e.g. perfumes, preservatives - photoallergy has been reported with aminobenzoates Long-term effect of using sunscreens every day not yet known

Sun protection strategies - SLIDE - importance

Repeated exposure to UV radiation can damage the eyes: - Short-term problems: excessive blinking; swelling; difficulty looking at strong light; acute photokeratopathy (sunburn of the cornea or snowblindness) - Long-term damage: cataracts (cloudiness of the lens); pterygium (overgrowth of the conjunctiva onto cornea); solar keratopathy (cloudiness of cornea); cancer of the conjunctiva; skin cancer of eyelids and around eyes

Sun protection strategies?

SLIP Clothing - SLOP Sunscreen - SLAP Hat - SEEK Shade - SLIDE Sunglasses - timing of exposure - duration of exposure 5 s + 2

Implications of SPF

SPF 15 means 15 times as much UVB is needed to produce minimal erythema on skin protected by the product compared to unprotected skin for the same length of exposure - Higher SPF sunscreen does NOT mean users can safely increase their duration of exposure to the sun i.e. cannot stay out twice as long with 30+ as 15

Sun protection strategies - SEEK

Shade can reduce overall exposure about 75% - trees or built structures (permanent or temporary) 1. Natural shade - Best shade trees have a dense canopy and dense foliage, with room for easy access beneath the canopy. 2. Built shade structures include: Rooves - Shade clothe - Shade sails - Portable structures e.g. tents, marquees; beach shelters, beach umbrellas

Sun protection strategies - SLIDE - sunglasses

Sunglasses: Sunglasses + a broad-brimmed hat can reduce amount of UV radiation reaching the eyes by up to 98% - Wrap-around, close-fitting, large sunglasses help to reduce reflected UV radiation & glare - Choose sunglasses which meet Australian Standard AS1067:2003 (Sunglasses: Category 2, 3 or 4) - Choose sunglasses with eye protection factor (EPF) 10 NOTE: The colour and/or darkness of the lenses do not indicate the level of UV protection

Sun protection strategies - SLOP

To filter out UV radiation - It is important not to rely on sunscreen alone - Use sunscreen on any skin that can't be covered by clothing

What is meant by 'water resistant' sunscreen?

Usually achieved with polymers which assist the sunscreen to bind to the skin