Australian mother Melissa McCaull is furious her nine-year-old son Damien was badly burnt after covering him 'head-to-toe' in Banana Boat sunscreen.

During a recent trip to the beach Melissa McCaull says she made sure her nine-year-old son was protected from the sun: hat, sunglasses, rashie, SunSmart shorts and Banana Boat sports sunscreen SPF 30.

But within a day, "bubble" and "wart"-like blisters began forming on Australian boy Damien's McCaull's skin, which had turned into the colour of an "overripe tomato".

"[I'm] furious that I put my trust in a product, your product, that for years has been marketed as a reliable sunscreen. This is not at all right or acceptable and Banana Boat needs to be held accountable," Melissa McCaull wrote in a post to Banana Boat's Facebook page.

SUPPLIED Melissa McCall's complaint against Banana Boat on social media is being shared rapidly.

Have you ever had any issues with your sunscreen? Email newstips@stuff.co.nz

READ MORE:

* Expensive sunglasses offer no more protection than cheapies

* Parents claim Jessica Alba's Honest Company sunscreen doesn't work

"He was crying from the pain and I was ready to walk into every shop that sold your product and dispose of it."

In the past 24 hours, the post has been shared nearly 3500 times and attracted comments from strangers with similar complaints and photos.

"Myself and my friend's baby had third degree burns on our face and arms and we applied every hour due to not wanting to be burnt," wrote Facebook user Kylie Kewin.

McCaull is adamant she followed the instructions on the tube, waiting for the product to sink in to her son's fair skin and re-applying it after he played in the waves.

She said Banana Boat had only sent her a generic reply until parent company Edgewell Personal Care was contacted.

"I want to know why this is happening, why it's causing second- and third-degree burns and not protecting us," she said.

Rachel Pullicino, Edgewell's marketing director, said the company was not aware of any specific issues with the Banana Boat Sport Performance SPF 30 product.

She said the product, like every sunscreen sold in Australia, met tough standards and complied with Therapeutic Goods Administration regulations.

"During summer we sometimes receive complaints from consumers who have experienced sunburn," she said.

"We want to reassure our consumers that we are confident that all Banana Boat sunscreen products labelled with an SPF offer the stated level of SPF if stored and applied as directed on the label."

Consumer advocacy group Choice tested six sunscreens last year and found four did not deliver on its SPF 50 claims.

Two of the four that failed were Banana Boat Baby Finger Spray and Banana Boat Sport tube, which only offered SPF 42.

But a quick search on social media uncovered numerous complaints regarding seemingly ineffective sunscreens along with photos of serious sunburns against popular brands.

These included complaints against the two brands that performed well in Choice's sunscreen research: Cancer Council and Nivea.

Associate Professor Rosemary Nixon, vice-president of the Skin and Cancer Foundation Inc, said that, in general, consumers could trust sunscreens to work and protect as stated if applied correctly.

She said common application errors at the beach included missing areas of skin, not applying a thick enough layer, and not re-applying after a swim or towelling.

"[In regards to the McCaulls' situation] I think it is very unusual. There are other causes of blisters though. There's phytophotodermatitis, which can cause an exaggerated sunburn reaction," she said. Phytophotodermatitis is a skin condition linked to sensitivity to some plants and fruits.

Australia's Database of Adverse Events Notifications, run by the Therapeutic Goods Administration, shows there were 37 adverse drug reactions to sunscreen products in 2014-15.

Seven of these reactions, including sunburns and blisters, were associated with Banana Boat products.

"In Australia, unlike in Europe, sunscreens with an SPF over SPF4 are classified as medicines and are required to be included in the Australian Register of Therapeutic Goods before they can legally be marketed in Australia," a TGA spokesperson said.

"These sunscreens are required to be manufactured in accordance with the principles of Good Manufacturing Practice and must comply with the requirements specified in the Australian and New Zealand Sunscreen Standard."