MBC has been involved in both laboratory and field bioassay work since 1978. Materials evaluated have included potentially hazardous wastes, cooling water effluents, complex sanitation effluents, production water, inland surface waters, underground tank wastes and rust inhibitors, dredge spoils, drill cuttings and muds, heavy metals, and various petroleum products.

MBC is certified by the Department of Public Health Environmental Laboratory Accreditation Program (ELAP, Certification Number 2762) to perform both acute and chronic effluent testing. Continued registration involves annual participation in the USEPA's annual Discharge Monitoring Report-Quality Assurance (USEPA-DMR-QA) studies for laboratory performance evaluations. As a participant in these studies, MBC provides toxicity data to the USEPA, State Water Resources Control Board, and the NPDES permittees.

Bioassay procedures follow those recommended by USEPA, California Department of Public Health, and Standard Methods. In addition, MBC has assisted in the development of bioassay protocols and conducted a workshop on the impacts of drilling muds and cuttings.

MBC bioassay facilities include 1,500 square feet of environmentally-controlled laboratory, with sub-systems for maintaining appropriate experimental environments. MBC routinely performs various acute and chronic aquatic bioassays and has conducted over 7,000 bioassay studies including 96-hour acute aquatic toxicity, 20-day bioaccumulation and 120-day chronic exposure tests.

Test organisms utilized have included: fathead minnows, topsmelt, inland silversides, three-spined sticklebacks, rainbow trout, purple sea urchins, sand dollars, giant kelp, red abalone, California halibut, speckled sanddabs, shrimp, mysids, amphipods, copepods, polychaetes, clams, mussels, freshwater fleas, and freshwater algae.