What are the risks of reusing plastic food containers

If you're trying to use less single-use plastic, you might have started taking your own containers to the shops or your local takeaway.

Movements such as Plastic Free July and ABC TV's War On Waste encourage people to make better use of their home-brought containers.

But should you be worried about food cross-contamination?

Tom Ross, an associate professor in food microbiology at the University of Tasmania, said if good food-handling practices were observed, the risk was small.

"As long as the container is pretty well clean and dry, the risk of any kind of cross-contamination is very low," he told Helen Shield on ABC Radio Hobart.

"If they're clean and they're dry, that's really quite safe."

Dr Ross said the biggest risk with home-brought containers was transferring contamination to other people's food.

But again he stressed the chances of that happening were very low.

"The only other way I can think of is if the person doing the service somehow got something on their hands and that then became transferred around the café or the shop," he said.

"But most of the food handlers know about hygiene, so really the same rules that we would use to protect the food that is already being served would be used to protect someone bringing in their own container."

Dr Ross said the risk of food poisoning from a dirty container was similar to the risk from using a dirty plate at home.

"Really it's up to the individual to say, 'I trust my own container. If I don't clean it it's my fault'," he said.

"Just as you would clean your own pots and pans and cups and plates at home, what would be the difference?"

And while the risk of cross-contamination is low, there are other reasons a shop might refuse to use a container that you've brought from home.

There are requirements for labelling of some meat products before they are presented for sale and removing the label or packaging at point of sale is not allowed.

But meat not already packaged, for example at a butcher, can be placed into containers provided by the buyer.

Reusing egg cartons by egg sellers is not allowed, but a buyer can request to have eggs put into a reused carton they have with them at a market.

And while a restaurant might not have containers to give you to take home your leftovers, you can pack it and take it yourself in your own container.

Local councils are usually responsible for enforcing food safety standards and can be contacted if you believe a food outlet is breaching them.

You can find more information on the food safety standards for Australia and New Zealand at foodstandards.gov.au.