Shareholders of Dolomatrix have approved the $58 million sale of four east coast hazardous waste businesses to Tox Free Solutions.

The purchase of Chemsal, BCD Technologies, Entech Industries and Waste Audit is scheduled to be completed next Wednesday.

The WA-based Tox Free in December conducted a $27 million capital raising to help finance the acquisition.

"These businesses will add significantly to our existing hazardous waste platform and will position Tox Free as the industry leader in this segment of the market," managing director Steve Gostlow said.

"We look forward to completing this transaction and focusing our attention on offering a broader range of services to our expanded client base."