A major fire at an Auckland chemical storage facility has been contained.

The Fire Service said 19 fire trucks were battling the blaze at Waste Management Technical Services in East Tamaki at about 1.30pm on Wednesday.

By 2pm the fire, burning in a 20-cubic-metre polyurethane pit, had been brought under control with around 40 firefighters still on site, the Fire Service said.

Fire crews being stood down from the fire were undergoing emergency decontamination with a hazardous materials team also on site.

The 400-square-metre building is used to store chemicals.Fire crews have contained a large industrial fire in East Tamaki.