Step 13 is a crucial step and attempts to account for reaction conditions in filtering away unrealistic impurities. All impurity reactions (including main product) are assessed, with respect to the three metrics: i) max relevance, which indicates the highest relevance score across all analogue reactions that suggest the reaction, ii) number of hits, which indicates the number of analogue reactions that suggest the reaction, replicated across the temperature range indicated for each reaction record (if present) and iii) temperature range, which is identified by the 5 th -95 th percentile of the top 10 % most relevant analogue reactions that suggested the reaction.