Octocrylene(in 2,499 products)Banned by Gov or classified as a carcinogen by IARC
Banned by Gov or classified as a carcinogen by IARC
1. Sunscreen - Physical sunscreens work by deflecting or scattering UV rays. Chemical sunscreens work by absorbing and dissipating the UV rays as heat.
Octocrylene is predominantly used as a chemical sunscreen ingredient.
Chemical sunscreens typically work by absorbing the UV rays from the sun and then dissipating it as heat.
Octocrylene prevents the chemical degradation of other substances and contains emollient properties. 
Octocrylene is an ingredient commonly found in sunscreens due to its versatility, it covers "mostly UV-B but also short UV-A wavelengths. It is often used in combination with other UV absorbers, especially cinnamates and butydibenzoylemethane, to achieve a higher sun protection factor (SPF) and to also add to their overall stability and water resistance.”   
"At present, in the United States and European countries, the majority (in some countries, > 80%) of sunscreens may contain octocrylene". 
However, as a chemical sunscreen, “These very chemically reactive UV filters are well known for inducing allergic contact dermatitis as well as photoallergic contact dermatitis (PACD)” , "Octocrylene appears to be a strong allergen leading to contact dermatitis in children and mostly photoallergic contact dermatitis in adults". 
Those who have had a history of photoallergic contact dermatitis should refrain from using octocrylene.
After using ketoprofen, a nonsteroidal anti-inflammatory drug (NSAID), do not use octocrylene. There seems to be an adverse drug-chemical interaction between ketoprofen and octocrylene. "photoallergic contact dermatitis in adults with an often associated history of photoallergy from ketoprofen" , "He [the patient] had a history of cutaneous allergic reactions after topical use of ketoprofen".  Ketoprofen can therefore tentatively be used as an indicator for octocrylene sensitivity though the mechanism of interaction remains unknown.  "Photosensitization to ketoprofen leads, in many cases, to photocontact allergy to octocrylene; the mechanism of this reaction is unknown." 
1. PubChem: https://pubchem.ncbi.nlm.nih.gov/compound/22571
2. Octocrylene, an emerging photoallergen (Arch Dermatol. 2010 Jul;146(7):753-7. doi: 10.1001/archdermatol.2010.132.)
3. Delplace, D., & Blondeel, A. (2006). Octocrylene: really non-allergenic? (Contact Derm., 54(5), 295–295. doi:10.1111/j.0105-1873.2006.0698a.x)
4. Contact and photocontact allergy to octocrylene: a review (Contact Derm. 2014 Apr;70(4):193-204. doi: 10.1111/cod.12205.)
5. Investigation of the sunscreen octocrylene's interaction with amino acid analogs in the presence of UV radiation (Photochem Photobiol. 2012 Jul-Aug;88(4):904-12. doi: 10.1111/j.1751-1097.2012.01142.x. Epub 2012 Apr 12)
1. Palau Sunscreen Ban (Senate Bill No. 10-135, SD1, HD1), https://www.icriforum.org/the-republic-of-palau-bans-sunscreen-chemicals-to-protect-its-coral-reefs-and-unesco-world-heritage-site/ - Octocrylene
2. EU CosIng Annex VI, LIST OF UV FILTERS ALLOWED IN COSMETIC PRODUCTS 
- Ref: VI/10
Safety and Hazards (UN GHS):
1. May cause long lasting harmful effects to aquatic life (H413)