[{"data":1,"prerenderedAt":73},["ShallowReactive",2],{"q-fire-114-1-fire-science-005":3},{"subject":4,"subjectSlug":5,"subjectKicker":6,"subjectShort":7,"question":8,"related":27,"sameNumber":52,"hasEssay":26},"火災學概要","fire-science","火災學 · Fire Science","火災學",{"id":9,"webId":10,"year":11,"session":12,"subject":4,"number":13,"stem":14,"options":15,"answer":20,"answerNote":21,"images":22,"imagesPending":23,"lawTimestamp":11,"explanation":24,"explanationDeep":25,"freq":12,"indexable":26},"fire-114-1-火災學概要-005","fire-114-1-fire-science-005",114,1,5,"火災煙毒氣體之危害主要是下列何種氣體？",{"A":16,"B":17,"C":18,"D":19},"CO","CO2","O2","N2","A",null,[],false,"本題考點：火災濃煙中各種氣體的毒理危害比較，考的是造成人員死傷的主要毒性氣體為何。\n【正解理由】一氧化碳是可燃物在氧氣不足下不完全燃燒的產物，火場濃煙中含量高；它與血液中血紅素的結合力遠大於氧氣（一般文獻列為二百倍以上），吸入後形成碳氧血紅素，使血紅素失去攜氧能力，並使剩餘的氧不易在組織端釋出，造成組織缺氧、判斷力下降以至意識喪失而無法完成避難。火災中因吸入濃煙致死者，多與一氧化碳中毒有關，故選 A。\n【逐項排除】\n(A) 一氧化碳為不完全燃燒的主要毒性產物，是煙毒氣體危害的主角，敘述正確。\n(B) 二氧化碳是完全燃燒的產物，本身毒性低，高濃度時的作用是排擠氧氣並使呼吸加深加快，屬窒息性氣體而非主要毒性氣體。\n(C) 氧氣是助燃氣體，火場的問題在於它被燃燒消耗而濃度下降，本身並非毒性氣體。\n(D) 氮氣為惰性氣體，既不助燃也不具毒性，並非煙毒危害的來源。\n【記憶點】火場真正奪命的多半不是火焰，而是不完全燃燒生成的一氧化碳。","火場中對人命威脅最大的並不是火焰本身，而是煙。煙的危害可分為三類：毒性氣體造成中毒、氧濃度下降造成缺氧、高溫氣體造成呼吸道灼傷，此外還有遮蔽視線使避難遲滯的間接危害。\n一氧化碳之所以是主角，關鍵在生成條件與毒理機制兩端。生成端：室內火災進入通風控制型燃燒後，可燃物在氧氣不足的條件下裂解，碳無法完全氧化成二氧化碳，一氧化碳的產率因而大幅提高；悶燒與衰退期的殘火同樣屬於高產率條件。毒理端：一氧化碳與血紅素結合成碳氧血紅素，其結合力遠高於氧氣，且會使剩餘的氧合血紅素更不易在組織端釋出氧氣，形成雙重缺氧。中毒程度與濃度及暴露時間的乘積相關，因此高濃度短時間與低濃度長時間都可能致命。\n其他常考的煙毒氣體要一起記：氰化氫來自聚氨酯、尼龍、羊毛、絲等含氮高分子的燃燒，毒性強、作用快；氯化氫來自聚氯乙烯等含氯材料，具強烈刺激性並具腐蝕性；二氧化硫來自含硫物質；醛類則來自木材與纖維素類的不完全燃燒。二氧化碳雖非主要毒性氣體，但它會使呼吸的速率與深度增加，等於加快其他毒氣被吸入的速度，這一點常被設計成陷阱選項。\n氧濃度也要並列著記：常態空氣中氧約占百分之二十一，火場中隨燃燒消耗而下降，濃度愈低愈影響肌肉協調與判斷力，最終使人無法自主避難。\n延伸考點：本科常把煙毒氣體與煙的流動特性（浮力驅動、煙囪效應、中性帶）合併命題。避難逃生設備、排煙設備與住宅用火災警報器的設置理由，都可以回到同一條主線來理解：在煙毒危害使人失去行動能力之前，先讓人察覺並完成避難。",true,[28,32,36,40,44,48],{"webId":29,"stem":30,"number":31,"year":11,"session":12},"fire-114-1-fire-science-004","下列有關隧道火災之敘述何者錯誤？",4,{"webId":33,"stem":34,"number":35,"year":11,"session":12},"fire-114-1-fire-science-006","依據我國公共危險物品之分類，下列有關可燃液體與易燃液體之敘述，何者正確？",6,{"webId":37,"stem":38,"number":39,"year":11,"session":12},"fire-114-1-fire-science-003","下列有關儲槽火災之敘述何者錯誤？",3,{"webId":41,"stem":42,"number":43,"year":11,"session":12},"fire-114-1-fire-science-007","油類火災沸溢（Boilover）與濺溢（Spilover）現象之發生區別，下列何者錯誤？",7,{"webId":45,"stem":46,"number":47,"year":11,"session":12},"fire-114-1-fire-science-002","建築物火災成長過程中有關衰退期的敘述何者錯誤？",2,{"webId":49,"stem":50,"number":51,"year":11,"session":12},"fire-114-1-fire-science-008","有關災害搶救標準作業程序之敘述，何者正確？",8,[53,57,61,65,69],{"webId":54,"year":55,"stem":56,"number":13},"fire-113-1-fire-science-005",113,"大樓火災常伴隨煙囪效應。所謂煙囪效應是指建築物內部受熱後熱氣流上升，冷空氣由下方填補，使得火災產生的煙霧會快速瀰漫整個建築物的現象。針對以上敘述，下列何者錯誤？",{"webId":58,"year":59,"stem":60,"number":13},"fire-112-1-fire-science-005",112,"鄰二甲苯的閃火點為 157℃，若鄰二甲苯於 157℃時的飽和蒸氣壓為 2.0 mmHg，試求其燃燒下限為何？",{"webId":62,"year":63,"stem":64,"number":13},"fire-111-1-fire-science-005",111,"在苯中置入油酸鎂等金屬鹼，係採取下列何種防止靜電發生的方法？",{"webId":66,"year":67,"stem":68,"number":13},"fire-110-1-fire-science-005",110,"已知乙烷、乙烯、乙炔的發火能量分別為 a、b、c，則 a、b、c 的大小關係為：",{"webId":70,"year":71,"stem":72,"number":13},"fire-109-1-fire-science-005",109,"下列有關二氧化碳（CO2）滅火劑之敘述，何者錯誤？",1785129965948]