The blast was reported just after 1 a.m. at Penn A Kem, The (Memphis) Commercial Appeal reported.
The explosion involved furfurylamine and methyl alcohol -- flammable chemicals that are harmful if inhaled and can burn skin.
The injured employees were taken to the Regional Medical Center in Memphis.
Police had the area cordoned off for about 4 hours.
Wisconsin business offering 'therapeutic cuddling' forced to close
Costly malfunction causes beer flood at Boston-area brewery