A Sydney boy has been hospitalised after swallowing part of a fidget spinner.

Fidget spinners can be dangerous for small children attracted to their bright colours and lights, with the consumer watchdog warning that cheaper models and those containing batteries are particularly worrisome.

The ACCC is always on the lookout for new fads that may present a safety hazard, and a variety of fidget spinners are currently being assessed.

A young Sydney boy was rushed to hospital on the weekend after swallowing part of a fidget spinner – the latest toy craze sweeping Australian playgrounds.

“Products containing button batteries or that have star- or blade-like spinners that may cause cuts and punctures are of particular concern,” an ACCC spokesman told AAP on Monday.

“Button batteries are very hazardous and can kill a child if ingested.

“The reports of cheaper products breaking easily and releasing small parts are (also) concerning.”

Fidget spinners range in price from a few dollars to over $100 and the quality varies accordingly.

The consumer watchdog says although spinners aren’t marketed at very young children their bright colours, lights, small size and popularity with friends and siblings means toddlers will be attracted to them.

“Any small parts released from a toy can pose a choking hazard for a child under three,” the spokesman said.

The Sydney boy’s mother on Friday night shared an X-ray of her son showing a small part of a spinner lodged in his stomach.

"Our son swallowed the disc of a fidget spinner last night & ended up at RNSH Emergency," she told the North Shore Mums Facebook group.

The toy, which contains ball bearings, had cracked and broken apart before her son swallowed part of it, she said.

"Ours are now in the bin & just want to make you all aware of what can happen with these things.

"He has to pass it within 2 days or we're looking at alternative methods of extraction."

A Royal North Shore Hospital spokesman said the boy has been released.

The ACCC in mid-May issued a recall for a specific fidget spinner that didn't have a secure battery compartment.

Queensland's Office of Fair Trading is leading a safety assessment of a variety of spinner products following reports of injuries associated with the toys.

"To date, several models have been tested ... and have passed safety tests," a spokesman for said on Monday.

"However, it should be noted that potentially thousands of different models are available on the market, and testing all would be difficult."

The spokesman said cheaper products are generally of a lower quality, more likely to break and become a danger to children.

Fidget spinners are one of the most popular toys for children this year and are marketed as a way to help kids release stress.