Sunscreens indicated to prevent skin cancer can actually cause skin cancer, according to a report from Friends of the Earth.

The report states "Consumers need to know that manufactured nanoscale zinc and titanium oxides are not the only choice and are not necessarily the most effective or safest choice for sun protection."

Nanoparticles, which can be some form of titanium oxides used in food products and cosmetic products, have been found to raise cancer risk in previous studies, as they enter all human cells and disrupt normal physiology.

Many sunscreens contain nanoscale particles of titanium dioxide or zinc oxide, which can be as small as a few molecules combined, according to an expert in nanotechnology. Use of nanoscale titanium or zinc oxides is believed to make the oily product less oily and easier to be adsorbed on to the skin.

According to the report, as many as six recent studies have shown zinc oxide nanoparticles can penetrate human skin to reach the blood and urine, kill brain stem cells in mice and destroy colon cells in very low concentrations.

Likewise, titanium oxide nanoparticle have also been found able to modify genes in pregnant mice and has been associated with Alzheimer's disease, autism and epilepsy.

Even worse, many cosmetic products that manufacturers claim have no nanoparticles actually contain certain nanoparticles, Consumer Reports were cited as reporting.

A health observer suggests using common sense and simple life necessity to minimize exposure to unnecessary risk from nanoparticles.

By David Liu and editing by Rachel Stockton