ALEXANDRIA, Va.—Dollar General could pay up to $3.4 million in fines from the Occupational Safety and Health Administration (OSHA) for workplace hazards at nine locations across Maine, North Dakota, Ohio and Wisconsin, reports Business Insurance.

The hazards included blocked aisles, emergency exits, fire extinguishers and electrical panels, many of which were obscured by store merchandise and other materials. During OSHA’s North Dakota investigation, OSHA found that at least six employees had been exposed to toxic vapors after several chemical containers ruptured.

“Dollar General continues to expose its employees to unsafe conditions at its stores across the nation,” OSHA Assistant Secretary Doug Parker said in a statement.

Dollar General was already facing more than $21 million in proposed fines since 2017 after OSHA inspectors visited 240 stores nationwide.