Ngowama-2019, i-US FDA yabhengeza isindululo esitsha esithi phakathi kwezithako ezili-16 ezisebenzayo ze-sunscreen ezikwimarike yase-US, i-zinc oxide kunye ne-titanium dioxide zongezwa kwiimveliso ze-sunscreen njenge-"GRASE" (Ngokubanzi ziyaziwa njengezikhuselekileyo nezisebenzayo). I-PABA kunye ne-Trolamine Salicylate azikho "GRASE" zokusetyenziswa kwi-sunscreen ngenxa yemiba yokhuseleko. Nangona kunjalo, oku kuqulethweyo akucaci, kwaye kuyaqondakala ukuba kuphela ii-arhente ze-sunscreen ezibonakalayo-i-nano zinc oxide kunye ne-titanium dioxide-ezikhuselekileyo nezisebenzayo kwizithako ezisebenzayo ze-sunscreen, ezinye ii-arhente ze-sunscreen zekhemikhali azikhuselekanga kwaye azisebenzi. Enyanisweni, ukuqonda okuchanekileyo kukuba nangona i-US FDA ibona i-nano-zinc oxide kunye ne-titanium dioxide njenge-"GRASE", akuthethi ukuba ezinye ii-arhente ze-sunscreen zekhemikhali ezili-12 azikho i-GRASE, kodwa azinazo idatha eyaneleyo yokhuseleko yokubonisa. Kwangaxeshanye, i-FDA ikwacela iinkampani ezifanelekileyo ukuba zibonelele ngedatha engaphezulu yenkxaso yokhuseleko.
Ukongeza, i-FDA ikwaqhube uvavanyo lweklinikhi malunga "nokufunxwa kwe-sunscreen ngesikhumba ukuya egazini" kwaye yafumanisa ukuba ezinye izithako ezisebenzayo ze-sunscreen kwi-sunscreen, ukuba zifunxwa ngumzimba kwinqanaba eliphezulu, zinokubangela iingxaki zempilo. Kwakamsinya nje emva kokuba iziphumo zovavanyo zipapashiwe, zavusa ingxoxo ebanzi kwihlabathi liphela, kwaye kancinci kancinci zabangela ukungaqondani ngabathengi abaqhelekileyo ababengayazi inyaniso. Babekholelwa ngokuthe ngqo ukuba i-sunscreens inokungena egazini kwaye ayikhuselekanga emzimbeni womntu, kwaye bade bakholelwa ukuba i-sunscreens iyingozi empilweni kwaye ayinakusetyenziswa.
Kuxelwe ukuba i-FDA iqeshe abantu abazithandelayo abangama-24, bahlulahlulwe baba ngamaqela ama-4, baza bavavanya ii-sunscreens ezine-sunscreens ezine ezahlukeneyo ezi-4 kule fomyula. Okokuqala, abantu abazithandelayo banikele nge-75% yolusu lomzimba wonke, ngokwemilinganiselo eqhelekileyo ye-2mg/cm2, amaxesha ama-4 ngemini kangangeentsuku ezi-4 ezilandelelanayo ukuze basebenzise i-sunscreen. Emva koko, kwaqokelelwa iisampuli zegazi zabantu abazithandelayo iintsuku ezi-7 ezilandelelanayo kwaye umxholo we-sunscreen egazini wavavanywa. Izifundo zibonise ukuba indawo yolusu lomntu omdala imalunga ne-1.5-2 ㎡. Ukuba ixabiso eliphakathi le-1.8 ㎡, ukuba libalwa ngokwesixa esiqhelekileyo, ukusetyenziswa kwe-sunscreen ngabantu abazithandelayo kumalunga ne-2 × 1.8 × 10000/1000 = 36g kuvavanyo, kwaye isixa se-4 ngemini yi-36 × 4 = 144g. Ngokwesiqhelo, indawo yolusu lobuso imalunga ne-300-350cm², ukusetyenziswa kwe-sunscreen kube kanye kwanele ukukhusela usuku lonke. Ngale ndlela, isixa esisetyenzisiweyo esibaliweyo yi-2×350/1000=0.7g, nokuba upende kwakhona ufakiwe, malunga ne-1 .0 ~1.5g. Ukuba uthatha isixa esiphezulu se-1.5 grams, ubalo luyi-144/1.5=96 amaxesha. Kwaye isixa se-sunscreen esisetyenziswa ngamavolontiya iintsuku ezi-4 ezilandelelanayo yi-144×4=576g, ngelixa isixa se-sunscreen semihla ngemihla esisetyenziswa ngabantu abaqhelekileyo iintsuku ezi-4 yi-1.5×4=6g. Ke ngoko, umahluko phakathi komthamo we-576 grams kunye ne-6 grams ye-sunscreen mkhulu kakhulu kwaye impembelelo icacile.
Ii-sunscreens ezivavanywe yi-FDA kolu vavanyo yayiyi-benzophenone-3, i-octoclilin, i-avobenzone, kunye ne-TDSA. Phakathi kwazo, yidatha yokufumanisa ye-benzophenone-3 kuphela edlula kakhulu into ebizwa ngokuba yi-"safety value", malunga namaxesha angama-400 adlula umgangatho, i-octocrylene kunye ne-avobenzone zombini zingaphakathi kwezihlandlo ezili-10, kwaye i-p-xylylenedicamphorsulfonic acid ayifunyanwa.
Ngokwethiyori, ukusetyenziswa rhoqo kwe-sunscreen ngamandla kuya kubangela isiphumo esidibeneyo. Akumangalisi ukuba ne-sunscreens zifunyanwa egazini phantsi kweemeko ezinzima kangaka zovavanyo. I-sunscreens zivunyiwe kwaye zisetyenziswa kangangeminyaka engaphezu kwamashumi eminyaka, amazwe amaninzi alawula i-sunscreens njengamayeza, kwaye okwangoku akukho datha yophando eyaneleyo yokungqina ukuba ineziphumo ebezingalindelekanga emzimbeni womntu.
Ixesha lokuthumela: Septemba-09-2022
