New consumer products based on nanotechnology, including cosmetics, cooking oil, golf clubs and toothpaste, are reaching the market at the rate of three or four a week, according to new research.

The latest update to the nanotechnology inventory maintained by the Project on Emerging Nanotechnologies (Pen) noted that the number of consumer products using nanotechnology has grown from 212 in March 2006 to 609 today.

Health and fitness items, which include cosmetics and sunscreens, represent 60 per cent of inventory products.

The list of nanotechnology merchandise contains everything from diamonds and cooking oil to golf clubs and iPhones.

One of the new items is Swissdent Nanowhitening Toothpaste with "calcium peroxides in the form of nano-particles".

In a testimony before the Senate Commerce Committee, Pen project director David Rejeski cited Ace Silver Plus, one of the nine nano-toothpastes in the inventory, as an example of the upsurge in nanotechnology consumer products in stores.

The hearing marked the start of US Senate debate on the future direction of the annual $1.5m federal investment in nanotechnology research and development.

Nanoscale silver is the most cited nanomaterial, found in 143 products or over 20 per cent of the inventory.

Carbon, including carbon nanotubes and fullerenes, is the second highest nanoscale material cited.

Other nanoscale materials explicitly referenced in products are zinc (including zinc oxide) and titanium (including titanium dioxide), silica and gold.

Surveys show that most Americans know little or nothing about nanotechnology, but nanotechnology was incorporated into more than $50bn worth of manufactured goods in 2006.

Lux Research estimates that $2.6tn worth of manufactured goods will incorporate nanotechnology by 2014, or about 15 per cent of total global output.

Despite a 2006 worldwide investment of $12.4bn in nanotech R&D, comparatively little was spent on examining its potential environmental, health and safety risks.

"Public trust is the 'dark horse' in nanotechnology's future," said Rejeski in his testimony.

"If government and industry do not work to build public confidence in nanotechnology, consumers may reach for the 'No-Nano' label in the future and investors will put their money elsewhere."

Rejeski added that the use of nanotechnology in consumer products and industrial applications is growing rapidly, and that the products listed in the Pen inventory are just the "tip of the iceberg".

Public perception about the real and perceived risks can have large economic consequences, he believes.

"How consumers respond to these early products in food, electronics, health care, clothing and cars is a litmus test for broader market acceptance of nanotechnologies in the future," said Rejeski.