Construction companies are being urged to check their rebar stocks following the latest warning over the quality of Chinese imports.

Trade body UK Steel claims there could be problems with imported rebar containing small amounts of other elements added in order to qualify the steel as “alloy” and thus benefit from an export tax rebate.

UK Steel said a “significant” proportion of the Chinese rebar sold in the UK contains boron in excess of 8 parts per million with some samples tested containing boron at 30 ppm.

Experts at the Welding Institute have issued guidance that rebar containing boron in excess of 5 ppm requires changes from the normal welding techniques used.

The only way of telling which Chinese rebar contains boron would be to test each bar.

Ian Rodgers Director, UK Steel, said: “Our advice to any fabricator with stocks of Chinese rebar is that they should urgently identify any bars containing more than 5 ppm of boron and segregate them.

“These bars should not be used in structures requiring welding until staff have been trained in the specific welding techniques required.

“Coming on top of the quality problems affecting some Chinese bars last year, this latest development does raise questions about the cost effectiveness and safety of sourcing outside of Europe.”