The fire was reported at 1:54 p.m. in two 40-foot shipping containers connected by a roof at 1460 Goodyear Road, near Fairfield.
The address is home to Organic Solutions, a private company that recycles green waste, turning it into mulch and soil.
About 23 firefighters responded to the blaze, which was declared under control at about 3:12 p.m.
No injuries were reported, Huyssoon said.