消防泡沫，又稱為水成膜泡沫（Aqueous Film-Forming Foam, AFFF），以覆蓋火焰、阻絕氧氣的方式滅火。AFFF中含有全氟烷基和多氟烷基物質（Per/Poly fluoro alkyl substances, PFAS），一種用於製造不沾鍋和防污地毯等產品的有毒化學物質。
燃燒「新興污染物」PFAS安全嗎？ 學界未有定論
今年10月，美國環保署（Environmental Protection Agency, EPA）甫將PFAS歸類為可能對人類健康造成危險的「新興污染物」。隨後竟發現全美各地的工業設施，皆在無意間燃燒了含有PFAS的消防泡沫。
美國國防部正在收集和銷毀來自世界各地美軍基地未使用的消防泡沫，其中含有危險化學品 全氟辛烷磺酸（Perfluorooctanesulfonic acid, PFOS）和全氟辛酸（Perfluorooctanoic acid, PFOA）。雖然軍方選擇的處置方式是燃燒，但關於燃燒這些泡沫的安全性研究卻很少。
美國疾病控制與預防中心（Centers for Disease Control and Prevention, CDC）、美國癌症協會以及美國環保署皆報告，PFAS與消防員和急救人員的癌症有關。
含PFAS的AFFF能夠有效滅火，也使其難以銷毀。沒有證據顯示PFAS在典型的工業燃燒方式下能完全分解。
PFAS化學品不易分解，且可以在人體和環境中持續存在數十年。根據美國CDC的資料，超過95%的美國人體內含有PFAS。
PFAS化學品未被美國歸類為「有害廢棄物」
研究發現，多達1/4的PFAS消防泡沫（2016年至2020年約為570萬磅）被送往燃料混合設施再處理，而不是直接送進焚化爐。
其中，大約320萬磅AFFF最終進入有混合燃料（包括有害廢棄物）許可的燃料混合設施。但是另外有250萬磅被送到沒有美國環保署燃料混合許可的設施中。
部分乾淨空氣倡議者質疑，AFFF是否被混入不被視為有害廢棄物的燃料中，或者這些設施是否正在儲存AFFF，並準備將其轉移到其他燃料混合設施，以及這些被轉移的燃料究竟在哪裡燃燒。
根據美國聯邦廢物處理法，PFAS化學品未被歸類為「有害廢棄物」，因此一直是由國防部而不是環保署決定，既有AFFF是否應視同有害廢棄物來處理。
PFAS在人體中的半衰期差異很大，從幾天到超過15年不等，取決於PFAS的種類。目前已知長鏈PFAS是最持久的。根據非營利應用科學和技術開發公司Battelle去年的白皮書，更長的半衰期使生物累積效應更強，潛在的相關健康影響更大。
州政府正設法保障人民免受PFAS侵害
非營利公共利益律師事務所Earthjustice稱，州政府正在設法保障人們免受PFAS的侵害。威斯康辛州通過了一項法律，限制使用含有全氟和多氟烷基物質的消防泡沫，其他幾個州也採取了類似的措施。
紐約、緬因州和威斯康辛州已通過相關法律，禁止州政府機構購買含有PFAS的食品容器。
在聯邦層級，美國環保署的規劃是2023年針對PFOA和PFOS這兩種最知名的PFAS類別，設定可執行的飲用水限制。美國環保署計畫根據美國超級基金法案（Superfund Law），將PFAS指定為有害物質，並提出一項規則，要求製造商全面報告其產品釋出情況。
2020財年國防授權法包括與PFAS相關的條款，限制國防部使用這些化學品，即工業規模PFAS污染的主要來源。
Just a month after the U.S. Environmental Protection Agency issued a new plan to cope with the wide spread of PFAS, a group of toxic chemicals used to make products like nonstick cookware and stain-resistant carpeting, warnings are emerging that industrial facilities across the country are unwittingly burning a firefighting foam containing PFAS chemicals.
The firefighting foam, known as Aqueous Film-Forming Foam, AFFF, puts out fires by creating a blanket that cuts off the oxygen the fuel needs to burn. AFFF contains chemicals known as perfluoroalkyl and polyfluoroalkyl substances, PFAS, that the U.S. Environmental Protection Agency has classified as “emerging contaminants” that are likely dangerous to human health.
The U.S. Department of Defense is collecting and destroying unused firefighting foam from U.S. military bases around the world that contains the hazardous chemicals PFOS and PFOA. Although incineration is the military’s selected disposal method, there has been little research on the safety of burning the foam.
The Centers for Disease Control and Prevention, CDC, and the American Cancer Society as well as the EPA have reported that PFAS are linked to cancer in firefighters and first responders.
The same qualities that make PFAS-based AFFF efficient at extinguishing jet fuel fires also make it difficult to destroy. There is no evidence that PFAS completely break down under typical industrial incineration practices.
PFAS chemicals do not break down, and they can persist in the human body and in the environment for decades. As a result, more than 95 percent of the U.S. population has PFAS in their bodies, according to the Centers for Disease Control and Prevention, CDC.
Bond’s analysis found that up to a quarter of the PFAS-based foam – roughly 5.7 million pounds from 2016 to 2020 – was sent to fuel blending facilities instead of being sent directly to incinerators.
Of that amount, about 3.2 million pounds of AFFF ended up at fuel blending facilities that have permits for blending fuels, including hazardous waste.
But another 2.5 million pounds of AFFF ended up at facilities that advertise themselves as fuel blending facilities but do not have EPA permits for fuel blending.
Some clean air advocates question whether AFFF is being blended into fuel that would not be considered as hazardous waste or whether those facilities are storing AFFF and transferring it to other fuel blending facilities, and where that transferred fuel is being burned.
PFAS chemicals are not classified as “hazardous waste” under U.S. federal waste disposal laws, so historically the Department of Defense, not the Environmental Protection Agency has been able to decide whether legacy AFFF should be treated as hazardous waste.
The half-life of PFAS in humans varies widely, from several days to more than 15 years, depending on which PFAS. Longer chain chemicals have been found to be the most persistent. Longer half-lives can impact bioaccumulation and potentially related health effects, according to a 2020 White Paper by the nonprofit applied science and technology development company Battelle, which manages eight government laboratories for the U.S. Department of Energy and Department of Homeland Security.
State governments are taking the lead on protecting people from PFAS, according to the nonprofit public interest law firm Earthjustice. Wisconsin has passed a law restricting the use of firefighting foam containing PFAS, and similar measures have been adopted in several states.
New York, Maine and Wisconsin have passed laws banning state agencies from purchasing food containers that include PFAS.
At the federal level, the EPA’s roadmap aims to set enforceable drinking water limits on the two best-known classes of PFAS – PFOA and PFOS – by 2023. The agency plans to designate PFAS as hazardous substances under the U.S. Superfund law and propose a rule that will require manufacturers to fully report on its release.
The National Defense Authorization Act for Fiscal Year 2020 included PFAS-related provisions that restrict the use of these chemicals by the Department of Defense, a major source of industrial-scale PFAS contamination.
※ 全文及圖片詳見：ENS
