The fire was 50 percent contained as of 8 p.m., according to fire officials, who said structures were no longer threatened and no evacuations were required.
Earlier in the evening, officials said the fire posed a small threat to the city of Duarte and the MTA Gold Line track.
Winds up to 10 mph pushed the fire toward the nearby MillerCoors brewery, where a structure defense was established, officials said.
At least five water-dropping helicopters were assisting firefighters on the ground.
There has been one civilian injury reported due to smoke inhalation.
Update: A fire burning in Irwindale is now 30 acres, 50% contained and there was 1 injury to a civilian for smoke inhalation, per @LACOFD.— Veronica Miracle (@ABC7Veronica) July 6, 2018
This photo was taken by @IrwindalePolice during the peak of the fire. pic.twitter.com/j3DCOVu3g9
The fire was first reported at around 5:40 p.m.