The decision follows recalls related to lettuce and the spinach linked E. coli outbreak that killed three people and sickened more than 200 in September 2006.
The Grocery Manufacturers Association (GMA), the trade association for global food and beverage companies, first petitioned the FDA nine years ago to extend the number of products that could be irradiated.
Irradiation exposes foods to ionizing radiation that kills insects, moulds and bacterium.
The technology, which can kill up to 99 per cent of pathogens, is seen by the industry as a means of ensuring food safety and extending shelf life and it claims that newer techniques eradicate the problem of leafy greens being left limp by the radiation process.
The US regulator has already determined that meat, poultry, molluscan shellfish and dried spices can be irradiated for safety in the US.
The FDA said the safety of irradiation of other types of lettuce remains under review, while fresh iceberg lettuce and fresh spinach that has undergone irradiation must bear the radura logo along with the statement ‘treated with radiation’ or ‘treated by irradiation’.
According to the agency, bagged iceberg lettuce and spinach can be irradiated if the packaging material has been approved for such use.
Science Policy Analyst at the Centre for Food Safety, Bill Freese, argues that irradiation will rob fresh spinach of some of its essential nutrients and he claims the technology avoids tackling the problem at its source.
"Irradiation is not the solution to food-borne illness,"said Freese. "In fact, it serves to distract attention from the unsanitary conditions of industrial agriculture that create the problem in the first place."
While irradiation is slowly gaining consumer acceptance in the US and several other countries, the technology has been slow to get support within many parts of Europe.
To date, about 50 countries have approved about 60 products to be irradiated, with the US, South Africa, the Netherlands, Thailand and France among the leaders in adopting the technology.
However, regulations on food irradiation in the European Union are currently not fully harmonised.
Directive 1999/2/EC establishes a framework for controlling irradiated foods, their labelling and importation, while Directive 1999/3 establishes an initial positive list of foods which may be irradiated and traded freely between member states.
So far the positive list has only one food category - dried aromatic herbs, spices and vegetable seasonings. Some countries, such as Belgium, France, the Netherlands and the UK, allow other foods to be irradiated.
A World Health Organisation (WHO) scientific report in 1992 found that irradiation posed no risk to human health:
"On the basis of the extensive scientific evidence reviewed, the report concludes that food irradiated to any dose appropriate to achieve the intended technological objective is both safe to consume and nutritionally adequate.
"The experts further conclude that no upper dose limit need be imposed, and that irradiated foods are deemed wholesome throughout the technologically useful dose range from below 10 kGy (gamma ray) to envisioned doses above 10 kGy,” the report stated.