Unlike many other barium compounds, barium sulfate is not very poisonous due to its low solubility in water. Indeed it is ingested in significant quantity regularly as a part of some medical procedures.
Barium sulfate is used as a high-temperature oxidizer in some green and white compositions, as well as being the oxidizer in the flash phase of some strobe compositions. It is also used as an additive in many firefly star compositions. Barium nitrate is more common in green pyrotechnic formulas, as it is a more amiable oxidizer and produces a superior color.