Potentially deadly Infinity cables may degrade in hot summer months, causing fires and electrocution, the Australian Competition and Consumer Commission warns.

The product, imported from China, was recalled more than a year ago after tests showed its poor-quality plastic insulation breaks down over time.

The cables were first installed in NSW homes in 2010, where they may start to crumble before the end of this summer. More than 2400km of the product – 62% of the total – remains unremediated nationwide, with just 35km fixed since the last update in October.

Commission Deputy Chairman Delia Rickard says homeowners with cables installed since 2010 in NSW and 2011 elsewhere should book an inspection without delay.

“In some circumstances suppliers, installers and property owners may be liable for any personal injury or property damage caused by Infinity cable installed in buildings,” she said.

“Suppliers and installers who are not actively notifying customers of the risk also potentially expose themselves to regulatory action.”