A Manchester lab that tests soil, water and other materials faces possible federal fines of more than $900,000 over allegations that workers were exposed to a hazardous chemical.

The U.S. Occupational Safety and Health Administration said an unspecified number of employees of Phoenix Environmental Laboratories Inc. complained to management about faulty ventilation and reported dizziness, light-headedness, headaches and unsteady walking. OSHA said the conditions can be caused by exposure to methylene chloride, a hazardous chemical and workplace carcinogen.

It proposed fines of $907,253, citing the company for six “willful violations,” 10 “serious violations” and one other than serious violation. Phoenix Environmental Laboratories may request an informal conference with OSHA, challenge the agency or comply with OSHA’s findings.

Phoenix Environmental Laboratories said on its website the “alleged violations” did not relate to the accuracy of results or integrity of analytical methods and it is correcting the problem.

It tests soils, water, sludge, solids and air for customers ranging from small business to large engineering firms and state and federal agencies.

Due to inadequate ventilation and recurring leaks from equipment in work areas and the use of methylene chloride in analyzing environmental samples, employees were allegedly exposed to methylene chloride, OSHA said. The permissible exposure limit was allegedly occasionally exceeded, the agency said.

OSHA alleged that despite its knowledge of the complaints, management at Phoenix Environmental Laboratories “took few effective measures to monitor and address the exposures and provide effective safeguards for its employees.”

“Phoenix Environmental Laboratories knew of its employees’ exposure to a highly hazardous and carcinogenic chemical, yet chose to ignore their complaints and failed to take effective corrective action,” said Dale Varney, Hartford area director for OSHA.

The agency said it also found exposure to flammable vapors, improper storage, unsafe handling and transfer of flammable chemicals, lack of suitable quick-drenching eye facilities where corrosives were used and electrical violations.

OSHA said Phoenix Environmental Laboratories allegedly failed to ensure employees were not overexposed to methylene chloride, perform initial exposure monitoring and inform employees of monitoring results and determine employees’ exposure levels when the control methods were known to be inadequate.

The company must ensure adequate ventilation; establish procedures to detect, contain and dispose of leaking methylene chloride; provide employees with protection of their skin, eyes and face from methylene chloride and other solvents; and make medical surveillance available and provide medical exams to exposed employees, OSHA said.

Stephen Singer can be reached at ssinger@courant.com.