Ingabe i-PTFE iphephile?

I-PTFE, eyaqanjwa umdondoshiya wamakhemikhali omhlaba i-DuPont ngeminyaka yawo-1930s, yaba wuphawu lokunethezeka kwekhishi njengokugoqa okunamathelayo kanye nephrosesa yokudla.

Kodwa i-PTFE ingase ifinyelele esiphethweni esinamathelayo - ngoba inqubo yokukhiqiza isebenzisa ikhemikhali engase ibangele umdlavuza, futhi i-US Environmental Protection Agency (EPA) ifuna kuqedwe ukusetshenziswa kwaleli khemikhali.

Ikhemikhali - ebizwa nge-perfluorooctanoic acid, noma i-PFOA - isetshenziselwa ukwenza amakhompiyutha abizwa ngokuthi ama-fluoropolymers, asetshenziswa ngokushintshana ukwenza i-polymer neminye imikhiqizo efana nowoyela kanye nezingubo zokuvikela amanzi kukhaphethi, izindwangu, isikhumba nephepha.

Kuyaziwa ukuthi i-PFOA isabalele egazini labantu abaningi (yize isezingeni eliphansi), lapho ihlala khona iminyaka eyi-10 ngaphambi kokuthi iqedwe.Ezilwaneni zaselabhorethri, i-PFOA ikhonjiswe ukuthi ibangela umdlavuza, ukulimala kwesibindi, ukukhubazeka kokukhula, ukulimala kwamasosha omzimba nokufa.Abukho ubufakazi obuqondile bokuthi iyingozi kubantu.

I-EPA icele iDuPont, nezinye izinkampani eziyisikhombisa ezisebenzisa i-PFOA ezinqubweni zokukhiqiza, ukuthi ziqede ukusetshenziswa kwayo.I-DuPont ivumile ukuthatha izinyathelo zokuqinisekisa ukuthi ngonyaka ka-2015, ikhemikhali ngeke idedelwe endaweni ezungezile isuka ezikhungweni zayo ezikhiqizayo, nakuba ingavumanga ukuyeka ukuyisebenzisa, noma ukuyeka ukwenza i-polymer.Inkinga ye-Dupont ukuthi, njengoba imile manje, ayikwazi ukwenza i-polymer ngaphandle kwaleli khemikhali, nakuba ithi ifuna enye indawo.

Impela, kunezinkomba zokuthi inkampani isinesikhathi eside yazi ukuthi i-PFOA iyingozi, kodwa yaqhubeka nokuyisebenzisa.

Ngo-2004, iDuPont yakhokha amaRandi ayizigidi ezingama-300 njengesixazululo esingaphandle kwenkantolo kubahlali ababalelwa ku-50,000 ababehlala eduze kwesikhungo sayo saseWest Virginia futhi abathatha isinyathelo seqembu ngokumelene nenkampani, bethi iyona enecala lokungcolisa amanzi endawo ngePFOA, okubangele. ukukhubazeka kokuzalwa nezinye izingozi zempilo.Inkampani yazinza ngaphandle kokuvuma icala.

Ngemva kwalokhu, ngo-2005, i-EPA yahlawulisa iDuPont isamba sezigidi ezingu-16.5 zamaRandi ngemva kokuthola inkampani yayazi iminyaka engaphezu kwamashumi amabili ukuthi i-PFOA iyingozi, futhi yathula ngayo.

Ingabe kufanele ngilahle ipani lami lokuthosa elingenanduku?

Uma kukhulunywa ngemikhiqizo enganamatheli uqobo, iDuPont ithi abukho ubungozi kubathengi.I-PFOA, ithi inkampani, isetshenziswa ohlelweni lokukhiqiza kodwa ikhishwa ngaleso sikhathi.Ayikho i-PFOA esele endaweni engabambeki emkhiqizweni wokugcina.

I-EPA iyavuma.'Okwamanje, i-EPA ayikholwa ukuthi sikhona isizathu sokuthi abathengi bayeke ukusebenzisa noma yimiphi imikhiqizo ehlobene nabathengi noma yezimboni equkethe i-PFOA', kusho iwebhusayithi ye-EPA.

Noma kunjalo, amapani okuthosa angagxili angakhulula ubuthi.Emazingeni okushisa aphezulu i-polymer yaziwa ngokunikeza i-cocktail yezinhlobo ezingu-15 zezinhlayiya ezinobuthi namagesi, okuhlanganisa i-trifluoroacetic acid (TFA) ne-phosgene.Lawa makhemikhali kwaziwa ukuthi anoshevu ezinyonini.Futhi kubantu baphathwa yikhanda elibuhlungu, ukugodola, ukuqaqamba kweqolo, nomkhuhlane - isimo esaziwa ngele-'polymer flu'.

I-DuPont iyakuvuma lokhu, kodwa ithi kubantu lesi simo siyalungiseka, futhi kunoma yikuphi kwenzeka kuphela emazingeni aphezulu okushisa, hhayi phakathi nokupheka okuvamile.

Nalokhu kuwukuhlakanipha okwamukelekayo phakathi kwamaqembu abathengi;e-Australia, ngokwesibonelo, 'ekuhlolweni komgwaqo' kaNovemba 2004 kwama-non-stick frypan, i-Australian Consumers' Association yathi:

'Kuyiqiniso ukuthi amakhemikhali afana ne-trifluoroacetic acid (TFA) angakhishwa ngezinye izinto zokumboza emazingeni okushisa aphezulu kakhulu.Kodwa ngeke kwenzeke ngesikhathi sokupheka okuvamile...Ucwaningo aluzange lubonise imiphumela eyingozi yesikhathi eside ye-TFA kubantu.Okwamanje abukho ubufakazi bokuthi ukupheka ngaphandle kwenduku kubangela ukuphepha.'

Cishe amaphesenti angama-80 wezitsha zasekhishini ezinganamatheli ezithengiswayo e-Australia zisebenzisa i-polymer - ezinye zenziwa ezinye izinkampani zamakhemikhali zisebenzisa inqubo efanayo ebandakanya i-PFOA.Azikho izitshalo ezikhiqiza i-polymer e-Australia.

Kodwa i-Environmental Working Group (EWG), iqembu elizimele labathengi base-US elingenzi nzuzo, liyaphikisana nalokhu.Ithi i-polymer iqala ukonakala ngemva kokuba izinga lokushisa lezinto zokupheka lifinyelele cishe ku-260°C (500°F), futhi liqala ukubola kakhulu ngaphezu kuka-350°C (660°F).Amafutha okupheka, amafutha kanye nebhotela kuzoqala ukuhangula nokubhema cishe ku-200°C (392°F), kanti inyama ivamise ukuthoswa phakathi kuka-200-230°C (400-450°F), kodwa izindawo ezishisayo epanini zingaba lula. yeqa leli zinga lokushisa.

I-off-gassing ingenzeka lapho i-polymer pan ishiywe ingagadiwe.I-polymer pan ingafinyelela ku-383°C (721°F) ngemizuzu emihlanu nje ishisiswe esitofini esivamile, sikagesi, kusho i-EWG.

Abathengi okufanele banqume?

Kubalulekile ukuqaphela ukuthi awukho umkhiqizo we-polymer oye wakhunjulwa e-US, Australia noma kwenye indawo.Mayelana nezinhlaka ezilawulayo, ziphephile – inqobo nje uma ungazivumeli zishise ngokweqile.

Kodwa ukuthola ukuthi ikhemikhali ohlelweni lokukhiqiza ikhonjwe njengebangela umdlavuza, okuvunywe yinkampani - kanye 'nobunzima' benkampani ne-EPA esikhathini esidlule - kungenzeka kube nomthelela.

Inkinga yezinkampani ezinjengeDuPont ukuthi, abathengi baya ngokuya bejezisa imikhiqizo ezimakethe ebonakala inophawu lombuzo mayelana nokuphepha kwayo, naphezu kokuqinisekiswa kwenkampani ukuthi iphephile, noma ngabe yayiyizinto eziyisisekelo zabathengi.Cabanga ngogwayi, ukudla okusheshayo, nezinhlamvu zasekuseni ezithuthukisiwe zikashukela.