The paper discusses the development and field-testing of the Marine Incineration Biological Assessment Sampler (MIBAS), used to assess potential effects of incinerating hazardous wastes at sea. In 1985, the U.S. EPA developed a strategy for the research necessary for measuring environmental and public health effects of incinerating hazardous wastes at sea. One area of this strategy addressed developing a way to sample incinerator emissions and introduce them into seawater for use as test media in toxicity tests. Responding to the strategy, EPA developed the MIBAS system, a system that samples incineration flue gas, cools the emissions, and collects them in seawater-filled impingers. Particulate matter and both semivolatile and nonvolatile organic species are collected by the train. The sample for use in toxicity tests includes the contents of the impingers, the probe, a flexible Teflon line, and a condenser coil. MIBAS tests have included spike-recovery, using a gas-phase spiking system to spike compounds into the emissions and then measuring them in the components of the MIBAS train.