SPF100 sunblock prompts warning

The first sunscreen rated SPF100 has arrived in New Zealand but the best sun-smart advice is to stay covered up and out of the sun, a Tauranga skin cancer survivor says.
The Neutrogena SPF100 product meets American testing standards accepted here. Neutrogena says its SPF100+ filters out 99 per cent of harmful UV rays and that SPFs above 100 are possible.
However, the company also says it advocates a "holistic sunsafe policy", which includes reapplying every two hours and staying out of the sun during peak times.
Ellen Orr, who established the Tauranga Melanoma Friends' group, was first diagnosed with melanoma in November 2008 and underwent three operations and four weeks of radiotherapy.
And though she did not know much about the new sunscreen, her advice was to reapply any sunscreen regularly.
"People are relying on sunscreen [too much] - they've got to keep out of the sun and keep covered up if they are in the sun. "I've been to seminars, and they emphasise that you need to keep out of the sun or keep covered up."
According to research, the Bay of Plenty region has the third-highest melanoma incidence rate in the country.
Melanoma is the fourth most common cancer in New Zealand, with about 2000 cases a year. It is reasonably common in younger age groups. Significant numbers of men and women between the ages of 25 and 39 get melanoma.
The Cancer Society said it was concerned that the use of such a high sun-protection factor, which in theory provides enough oomph for day-long cover, will give a false sense of security, with people skipping necessary reapplications.
Fiona Mawley, spokeswoman for the Cancer Society, advises that sunblock should be reapplied every two hours - regardless of SPF ranking.
"There has been discussion that SPF30+ is all that's necessary and by using a higher SPF there is concern that the people will think they have a shield or armour on."
Johnson & Johnson's senior international director of technology, Dr Curtis Cole, said most people apply only a third to half the sunscreen they need, reducing the coverage they think they're getting.
"High SPF helps compensate for under-application," he said.
Dr Cole said while higher SPFs may only be filtering out a few per cent more of UV rays, it is "the amount that is getting through the filter that matters", so increased filtering could significantly reduce exposure to damage.
Vienna Richards, spokeswoman for the Auckland Regional Health Service, agrees wearing sunblock as your only protection is unwise.
New Zealand's skin cancer rate is high with nearly 400 deaths a year - two-thirds from melanoma.
There are about 67,000 skin cancers reported each year compared with about 16,000 other cancers.
The high rates are in part caused by the skies above New Zealand which have up to 50 per cent more UV light than some northern places.