The ACT's work safety watchdog is launching a blitz on Canberra building sites amid concerns about the potentially "catastrophic consequences" of the inappropriate use of precast concrete.
The site audits, which start from Tuesday, come in response to incidents earlier this year. In January, a 3.7-tonne concrete slab fell 17 metres from a Braddon building site, crushing the toilet block of a nearby business and damaging cars.

WorkSafe ACT inspectors will visit commercial and residential construction sites in the next three to four weeks, checking compliance with safety practices and providing education to workers.
Inspectors will scrutinise documentation relating to precast panels, as well as check on the concrete material, during the site audits.
ACT Work Safety Commissioner Greg Jones said the use of precast concrete posed a safety risk to construction workers when not "handled correctly".
"Precast concrete panels are becoming more popular in the construction of both commercial and residential buildings due to the speed and efficiency of their installation," Mr Jones said.
"The most common issue associated with the use of precast panels is the collapse of the panel during or after their installation.
"This is usually as a result of workers not being suitably qualified or licensed to undertake the work or failure to follow site specific Safe Work Method Statements."
Mr Jones said the scale of the audit beyond the next month would depend on the findings of the first "15 or so" site audits.
Employment and Workplace Safety Minister Rachel Stephen-Smith said a report would be publicly released following the blitz, which would help industry improve work site safety practices.
"We want to ensure that those working in the construction industry have access to a safe working environment, especially when using precast concrete panels," Ms Stephen-Smith.