Fire officials say someone mixed an acid into tanks of bleach stored inside industrial drums at the Sea Crest Linen Supply company, leading to an explosion just before noon.
Bleach is a commonly used ingredient in the manufacturing of linens.
Several workers were given oxygen at the scene, but no serious injuries were reported.
Some of the roughly 200 employees working at the business, which supplies linens to restaurants and hotels, described a loud explosion before they left the building.
"We heard a whole 'boom' and we went out. We got scared, we all got scared. We didn't know what happened," said an employee.
"We heard a big explosion, so it was time to get out of there," said another. "And then it started getting strong, smelling strong. It was time to go."
"Everybody got outside safe, but thank god, you know, nothing happened. Thank god everybody was protected," said a third.
Following the explosion, management aired out the building to get rid of strong chemical smells and dangerous levels of vapor, and workers were able to return to the building by the end of the day.