Based on the designator (24H8) and the name, it is a proprietary manufacturer that is long out of business. I have run into this type of problem before on remodels. The best advice I can offer is to look up the designation 24H8 in the historical manual put out by the Steel Joist Institute to determine what the original design load capacities were. Each manufacturer (and there were several) was permitted to utilize their own proprietary designs / material sizes as long as they met the standard load capacity tables. If you are in a pinch and don't have the historical manual, sometimes the SJI will assist in providing that information, it really depends on who assists in answering your question.
If you need to look at an updated, specific loading for the joist, you will need to take detailed measurements of the entire joist and build a model using the appropriate steel capacities under the original and revised loading scenario. IIRC, all the steel needs to be set to 36ksi strengths.