冰箱除冰悲劇警示：為何尖銳物除冰會引發爆炸？

河南信陽發生一起本可避免的悲劇。一家雪糕店的店主王某（化名）在營業前，用菜刀試圖清除冷凍櫃內的積冰。沒想到，這個簡單的動作引發劇烈的爆炸。事故中，王某被飛濺的金屬碎片擊中要害，送醫後不治；他的妻子張某則全身多處燒傷，面積達60%。整間店鋪也在瞬間被摧毀。事後經消防單位鑑定，王某所使用的刀具刺穿冷凍櫃內的蒸發器管路，造成內部R600a（異丁烷）制冷劑大量釋放，並於接觸到廚房的明火後爆燃，引發這場嚴重意外。

要了解這起事件的根本原因，得從冰箱的內部結構說起。現代冰箱冷凍室的蒸發器管線，通常是由厚度僅有0.5到1毫米的鋁管或銅管製成，這些管線直接嵌入冷凍室的內壁，距表面僅約2至3公分。在冰箱運轉時，管內制冷劑壓力可達0.55-0.6MPa。一旦尖銳物體如刀尖、螺絲起子或金屬鏟接觸並破壞這些管路，極有可能造成氣體洩漏與爆炸風險。例如，實驗顯示使用水果刀鋒利的一端去剷冰時，壓力甚至能超過200MPa，足以刺穿鋼板。即使當下未造成損壞，鋁管也可能因金屬疲勞在數週後裂開，形成延時爆炸的隱患。

R600a作為現今家用冰箱最普遍使用的制冷劑，雖然冷效高、環保，但本質上卻是一種高度易燃的氣體——異丁烷。這類氣體的爆炸極限在空氣中僅需濃度達到1.8%至8.4%之間即可引燃。一台冰箱內所含的R600a量約為50至80克，其中每克完全燃燒能釋放約50千焦耳能量，相當於12根火柴的燃燒量。若80克制冷劑在密閉空間內釋放，遇明火產生的爆炸威力幾乎等同於400克TNT炸藥。信陽事故中，鋁管被破壞後，制冷劑以每秒3公尺的速度高速噴出，低溫狀態下更造成管線金屬脆化。當制冷劑碰上冰箱內照明電路產生的微小火花，短短0.3秒內即引發爆燃，現場瞬間成為火海，溫度一度飆升至1200℃。

為避免這樣的災難再次發生，專家建議應遵循五個安全除冰步驟。首先，在除冰前應先拔掉電源並清空冷凍室內食物，靜置至少30分鐘以上，讓溫度自然回升。接著可放入裝有60℃熱水的金屬盆並關閉冰箱門，利用熱氣加速積冰融化。冰融之後，立即用乾毛巾將水分擦乾，防止水分滲入電路導致短路或觸電。完成除冰後應開門通風至少兩小時，自然乾燥內部空間。為預防日後再結冰，建議每月用甘油擦拭冰箱門封條，並以A4紙檢測密封性是否完好。

反之，一些常見的除冰誤區應絕對避免，例如直接用刀具劈砍積冰、用鹽巴腐蝕冰面、使用電吹風高溫吹冰、甚至用重物敲打冷凍室內壁。這些方法不僅可能破壞內部管路，更可能引發火災或爆炸。2019年在中國瀋陽就曾因為用刀除冰導致兩人雙目失明；2021年杭州一場火災則是因為電吹風高溫熔化電線絕緣層所引起；而在珠海，更有超市員工因除冰失誤釀成事故被判負有重大責任。

為此，從2024年起，大陸要求所有新出廠的冰箱必須加裝防護鋼板於蒸發器管路上，同時在冷凍室明顯處張貼「禁止使用尖銳工具除冰」的安全標示。各大品牌如海爾，也相繼推出自動除霜冰箱，透過智慧化技術減少人工除冰的需求。最後，信陽冰箱爆炸事故的監控畫面令人痛心，從王某開始動手除冰，到冰箱發生爆炸，僅僅用47秒。這短短一分鐘的省事之舉，卻讓一個家庭陷入終生遺憾。相較之下，用熱水除冰不過15分鐘，卻能保護家人與自己免於災難。請牢記——冰箱不是冰雕，暴力除冰等於親手引爆定時炸彈。轉發這篇科普文章，或許能在未來救下一個家庭。

Fridge Defrosting Tragedy Warning: Why Sharp Tools Can Cause Explosions

A preventable tragedy recently occurred in Xinyang, Henan. The owner of an ice cream shop, Mr. Wang (alias), attempted to remove frost from a freezer before opening for business by using a kitchen knife. Unexpectedly, this simple action caused a powerful explosion. Mr. Wang was fatally injured by flying metal fragments and later died in the hospital, while his wife, Ms. Zhang, suffered severe burns over 60% of her body. The entire shop was also destroyed in an instant. According to the fire department’s investigation, the knife punctured the evaporator tubing inside the freezer, causing a large release of R600a (isobutane) refrigerant, which ignited upon contact with open flames in the kitchen, resulting in a devastating blast.

To understand the root cause of this accident, it’s important to know how a fridge is built. Modern freezers have evaporator tubes made of aluminum or copper with a thickness of only 0.5 to 1 millimeter, embedded just 2 to 3 centimeters beneath the inner surface of the freezer wall. While in operation, the refrigerant inside these tubes is under pressure (typically 0.55 to 0.6 MPa). When a sharp object like a knife tip, screwdriver, or metal spatula damages the tubing, it can cause a gas leak with explosive consequences. Experiments show that using the sharp edge of a fruit knife to chip at ice can exert pressure exceeding 200 MPa—enough to puncture steel. Even if damage isn't immediately visible, the aluminum tubing can suffer metal fatigue and rupture weeks later, resulting in delayed explosions.

R600a is the most commonly used refrigerant in modern household refrigerators. Though it is efficient and environmentally friendly, it is also a highly flammable gas—specifically isobutane. The explosive concentration range in air is between 1.8% and 8.4%. A typical fridge contains about 50 to 80 grams of R600a, and each gram can release around 50 kilojoules of energy when ignited—equivalent to the energy of 12 burning matchsticks. If 80 grams of R600a were released into an enclosed space and ignited, the resulting explosion would be comparable to 400 grams of TNT. In the Xinyang incident, the aluminum tube was punctured and the refrigerant sprayed out at 3 meters per second. The extreme cold caused the metal to become brittle. When the gas encountered a spark—possibly from the fridge light circuit—it ignited in just 0.3 seconds. The store was instantly engulfed in flames, with temperatures surging up to 1200°C.

To prevent such disasters, experts recommend five key safety steps for manual defrosting. First, unplug the fridge and remove all contents from the freezer. Let it sit for at least 30 minutes so the temperature naturally rises. Then place a metal basin filled with 60°C hot water inside and close the door to let the steam melt the ice. Once the frost melts, immediately wipe the interior dry with a towel to avoid short circuits from moisture. After defrosting, leave the door open for at least two hours for ventilation. To reduce future frost buildup, apply glycerin to the door seal monthly and test seal integrity with an A4 sheet of paper.

Conversely, several common but dangerous methods must be avoided at all costs—such as hacking at frost with knives, applying salt to the ice, using high-heat hairdryers, or pounding the freezer walls with heavy tools. These approaches can seriously damage internal tubing or cause fires and explosions. For instance, in 2019, a defrosting accident in Shenyang caused blindness in two individuals. In 2021, a fire in Hangzhou was caused by a hairdryer melting the insulation on internal wiring. In Zhuhai, a supermarket worker was held responsible for a similar accident due to defrosting errors.

In response, starting in 2024, China mandated that all newly manufactured refrigerators be equipped with protective steel plating over evaporator tubing and required clear warning labels in freezer compartments stating, “Do not use sharp tools for defrosting.” Major brands like Haier have also launched automatic defrosting models using smart technology to reduce manual intervention.

The surveillance footage from the Xinyang explosion is heart-wrenching. It shows that from the moment Mr. Wang began defrosting to the point of the explosion, only 47 seconds passed. This single minute of trying to save time resulted in a lifelong tragedy for his family. In contrast, using hot water for defrosting takes just 15 minutes and could have prevented the disaster entirely. Let this serve as a reminder: a fridge is not an ice sculpture. Using force to remove ice is akin to lighting a time bomb with your own hands. Share this safety message—doing so might save a life.