Researched
Sources:

EWG Responds to General Mills and Quaker Oats:
‘Legal Is Not the Same as Safe’
https://www.ewg.org/news-insights/news-release/ewg-responds-general-mills-and-quaker-oats-legal-not-same-safe

EWG investigation:
Dangerous agricultural chemical
chlormequat found in popular oat-based products
https://www.ewg.org/research/ewg-investigation-dangerous-agricultural-chemical-chlormequat-found-popular-oat-based

Molecular and Immunological Characterization of Gluten Proteins
Isolated from Oat Cultivars
That Differ in Toxicity for Celiac Disease
https://pmc.ncbi.nlm.nih.gov/articles/PMC3524229/

Celiac disease, gluten-free diet, and oats
https://pubmed.ncbi.nlm.nih.gov/21294744/

Glyphosate Contamination in Food Goes Far Beyond Oat Products
https://www.ewg.org/news-insights/news/2019/02/glyphosate-contamination-food-goes-far-beyond-oat-products