The ACTU is close to finalising alcohol and other drug guidelines that support oral testing rather than the urine sampling regime favoured by some employers.
Overall union membership might have fallen to as low as 10% if density had not stabilised across Australia's service and public sectors, new research has shown.
Unions lost almost 93,000 members in the 12 months to August last year and density plunged to new lows of 17% overall and 12% in the private sector, according to the ABS.
Unions gained 6,000 members in the 12 months to August last year, but growth failed to keep pace with the size of the workforce, so density fell from 18.4% to 18.2% overall and from 13.2% to 13% in the private sector, according to the ABS.