Men's Regular Fit Non-Iron Oxford Dress Shirt vs Men's Farrier's Work Shirt: which is safer?

Where these two actually differ

• We flag Formaldehyde or formaldehyde releasers in durable-press finish, Azo dyes in polyester or dye bleed on white/light colors, Finishing resin degradation over repeated wash cycles and Antimony in polyester fiber itself on the Brooks Brothers and not on the Patagonia.
• We flag Formaldehyde releasers in durable-press resins and Chemical off-gassing or skin irritation from finish residues on the Patagonia and not on the Brooks Brothers.
• The Brooks Brothers is Cotton/polyester blend with non-iron (durable-press) finish where the Patagonia is Organic cotton, standard construction, which is most of the difference in these two grades.
• The gap is 70 points, wide enough that this is not a close call, and the Patagonia is the one to buy.