An annotated bibliography of SBF publications was prepared. All the relevant information was synthesized and interpreted in a technical review and in the form of an ecological risk assessment for SBF discharges to deep offshore waters of the Gulf of Mexico. Bulk SBFs are not permitted for discharge to waters of the Gulf of Mexico, but SBF cuttings are. The SBF cuttings form clumps in the receiving waters and quickly settle to the bottom following discharge to the ocean. SBF base fluids are biodegradable.
Esters degrade most rapidly.
Biodegradation often causes depletion of oxygen in sediments. SBFs and SBF base fluids have a low toxicity to water column and sediment-dwelling marine organisms. However, high concentrations of SBF in sediments produce adverse effects in benthic communities. The usual response is the loss or decrease in abundance of several species of benthic fauna and an increase in the abundance of a few opportunistic species, leading to an overall decrease in species diversity. This effect probably is caused by organic enrichment of the sediments with biodegradable SBF base fluid, leading to sediment hypoxia.