BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene) are synthetic antioxidants used as preservatives in almost every kind of personal care product and many food items.
You can find BHA/BHT preservatives in almost any type of cosmetic/skincare products. It’s been linked to hormonal disruption, skin issues, and cancers.
The US Government restricts BHA and BHT to .2% or below within food and cosmetics. Canada and Japan have even tighter restrictions of .1% or below. BHA is a known carcinogen and endocrine disruptor to the U.S. state of California (Known Carcinogens and Reproductive Toxicants, California Proposition 65) . The European Chemicals Agency has also scheduled BHA for further research due to its endocrine disrupting properties .
 NIH, NCBI. Effects of butylated hydroxyanisole on the development and functions of reproductive system Jeong SH1, Kim BY, Kang HG, Ku HO, Cho JH. (2005). https://www.ncbi.nlm.nih.gov/pubmed/15664432
 CDPB (California Department of Public Health). Cosmetics Containing Ingredients Linked to Cancer or Reproductive Harm. Page 9. (2009-2015). https://www.cdph.ca.gov/Programs/CCDPHP/DEODC/OHB/CSCP/CDPH%20Document%20Library/DataReport.pdf
 OHHA (California Office of Environmental Health Hazard Assessment). Known Carcinogens and Reproductive Toxicants, California Proposition 65. Page 6. https://oehha.ca.gov/proposition-65/proposition-65-list
 Ministry of Environment and Food. Exposure of children and unborn children to selected chemical substances. Page 82. (2017). https://www2.mst.dk/Udgiv/publications/2017/04/978-87-93529-84-7.pdf
 ECCHA (European Chemicals Agency). Justification Document For The Selection Of A CoRAP Substance. Page 8. (2015). https://echa.europa.eu/documents/10162/13628/corap_justification_246-563-8_fr_15256_en.pdf/ab031c03-6e40-c32f-4e3f-f5ef6b1c7dad