Use the product-family hierarchy
Unsaturated Polyester Resin, or UPR, is the broad resin family. The current ISO Fire Retardant Resin TDS places this product within that family and describes an isophthalic-based fire-retardant grade.
This is not a comparison between unrelated materials. The useful question is whether the finished component and project requirement call for this specialised ISO FR product route rather than another published UPR grade.
Do not invent a missing general-isophthalic comparison
The repository does not list a separate ordinary isophthalic resin product. It would therefore be misleading to publish a performance comparison or imply how an unlisted grade behaves. Isophthalic terminology alone does not establish fire performance, project compliance or service suitability.
If a specification names isophthalic chemistry, keep that wording in the enquiry and review the current ISO FR TDS alongside the complete project requirement.
Select a published grade for the actual purpose
Use the UPR family page for broad resin-grade orientation, standard Fire Retardant Resin for the separately published FR route, and Vinyl Ester for its separately published product category. Product names do not replace grade-specific documentation or a finished-system requirement.