OFAC produces several lists which contain people, organisations, vessels and aircraft with whom trade is sanctioned.  The reach of OFAC is such that if any aspect of the transaction interacts with the US, then it falls under the purview of OFAC.  Given the global use of the US Dollar, technical infrastructure and size of the market, most global organisations will consider the OFAC list as critical to comply with. 

All the lists are publicly and freely available (https://www.treasury.gov/resource-center/sanctions/Pages/default.aspx) however most organisations will consume this data as part of a larger screening programme, which normally consumes this list, other sanctions list and Politically Exposed Person (PEP) lists to ensure that data is consumed in the most efficient method.