Business Insider recently asked more than two dozen bartenders to “weigh in on what they’d love to tell customers but can’t.” Their response: Think twice about ice because it may be unclean.

Of course, this is just anecdotal advice from a handful of mixologists. While some bars and restaurants may not rigorously clean their ice machines, others may do so.

Here’s what you should keep in mind:

Yes, in some cases ice has been found to be contaminated:

Some studies and news stories over the past decade lend credibility to these bartenders’ warning about ice machines. In 2014, HuffPost spoke to two experts on ice and ice machine contamination. Three main issues were discussed in the piece: mold, bacteria, and whatever is found on peoples’ hands.

These contaminants can come from a variety of places. Mold can build up in ice machines—especially if they’re not cleaned or are turned off for a period of time.

And despite the Safe Drinking Water Act in 1974 and EPA standards for clean water, water can become contaminated with bacteria while being frozen and stored from ice making machines or from contact with other contaminated food.

A 2011 study by researchers at the University of Nevada, Las Vegas examined the prevalence of bacteria in ice and soda dispensed at Las Vegas restaurants. The study found that 33.3% of ice samples contained heterotrophic bacteria—higher than EPA standards. It also found that “72.2% were positive for presumptive coliform bacteria presence.” (The soda samples fared far worse in both categories.)

And of course, there’s human negligence. Bartenders who work while sick, don’t wash their hands before scooping ice, and use their hands to touch ice can contaminate ice from their hands. (Norovirus can be spread this way.)

“Most people don’t realize that not washing their hands could cause death,” Debra Huffman, a microbiologist at the University of South Florida, explained to NBC News in 2006. “They just don’t see the risk. It’s not going to smell funny. It’s not going to look funny. These are microscopic, and so you’re not going to see it. You wouldn’t known it happened.”

How restaurants can avoid ice and ice machine contamination:

Restaurants and bars can take steps to avoid contamination, and a big part of that is treating ice with the same safety precautions that they would treat food, Martin Bucknavage, senior food safety extension associate at the Department of Food Science at Pennsylvania State University, explained to HuffPost.

This is also codified by the Food and Drug Administration. Ice is defined as food by the U.S. Food and Drug Administration Food Code, according to Food Safety Magazine.

Cleaning and sanitizing ice machines can also help prevent contamination, and it’s mandated by law.

“Ice machine cleaning is governed by Food Law 2009 Chapter 4 part 602.11 section (E) item (4a and b), which states that the machines must be cleaned “at a frequency specified by the manufacturer,” which in most instances ranges from two to four times per year, or ‘at a frequency necessary to preclude accumulation of soil or mold,'” Food Safety Magazine notes. “Ice machine sanitizing is governed by Chapter 4 part 702.11, which states that the ice contact surfaces must be sanitized after each cleaning.”

Restaurants that don’t comply can be levied hefty fines.

Food Safety Magazine offers tips to combat human error, including washing hands, proper ice scoop handling, and not handling ice with hands.

The takeaway:

There are cases in which ice contamination has caused serious illness or death. However, your immune system can probably handle some contact with contaminated ice, experts told HuffPost.

As with any foodborne illness, there are certain groups who are more at risk of getting sick, including the very young, the very old, those with HIV/AIDS, those with diabetes or autoimmune disorders, or pregnant women, according to FoodSafety.gov.

Some customer tips for avoiding contaminated ice include paying attention to the cleanliness and health ratings of restaurants and bars you visit. And if you’re really concerned, skip the cocktail and stick with beer, wine, cider, or a shot.

Business Insider最近采访了二十多位调酒师，问他们“哪些事情是他们乐于告诉顾客却不能说的”。他们的回答是：在加冰前仔细考虑一下，冰块可能不干净。

当然，这只是调酒师的坊间建议。尽管一些酒吧和餐厅可能不会严格清洁制冰机，但另一些或许会这么做。

以下是你需要注意的一些事项：

没错，有时冰块被污染了

过去十年里的一些研究和新闻故事，让这些调酒师关于制冰机的警告增添了不少可信度。2014年，赫芬顿邮报（HuffPost）就冰块和制冰机污染的问题与两位专家进行了探讨。文中讨论了三大问题：霉菌、细菌和人类手上的附着物。

这些污染物可能来自各种地方。霉菌可能滋生于制冰机里——尤其是如果制冰机没有得到清洁，或是有一段时间没用过。

尽管1974年美国推出了《安全饮用水法案》（Safe Drinking Water Act），美国环保局（EPA）对于清洁水也有标准，但在制冰机制冰和储藏的过程中，或是与其他被污染的食物接触的过程中，水也可能受到细菌的污染。

位于拉斯维加斯的内华达大学（University of Nevada）的研究人员在2011年进行了一项研究，检查了拉斯维加斯餐厅里的冰块和苏打水中细菌的分布情况。研究发现，有33%的冰块样本都含有异养细菌，这个值超出了环保局规定的标准。此外，“在大肠菌群的检测中，有72.2%的样本呈阳性。”（苏打水的样本在这两项检测中情况更加糟糕。）

当然，人类的玩忽职守也是原因之一。带病工作的调酒师在捞取冰块之前如果不洗手，并直接用手接触冰块，就会污染冰块。（诺瓦克病毒就能通过这种方式传播。）

南佛罗里达大学（University of South Florida）的微生物学家黛布拉·霍夫曼在2006年对美国全国广播公司新闻频道（NBC News）解释道：“大部分人没有意识到不洗手会导致死亡。他们不知道这种风险。闻起来不会有什么特别，看起来也没什么特别。这都是微观的变化，所以你看不到。你不知道它已经发生了。”

餐厅如何避免冰块和制冰机被污染

宾夕法尼亚州立大学（Pennsylvania State University）食品科学系的食品安全宣传高级副主管马丁·巴克纳瓦吉对《赫芬顿邮报》解释道，餐厅和酒吧可以采取措施避免污染，其中重要的一点在于对冰块使用等同于食品的安全保护措施。

美国食品和药物管理局（Food and Drug Administration）对此也做出了规定。《食品安全杂志》（Food Safety Magazine）表示，在《美国食品和药物管理局食品法典》（U.S. Food and Drug Administration Food Code）中，冰块被定义为食品。

对制冰机进行清洁和消毒也有助于防止污染，法律对此有强制规定。

《食品安全杂志》指出：“2009年《食品法》第4章602.11部分第E条（4a和b）对制冰机的清洁做出了规定，其中要求机器必须按照‘制造商指定的频率’进行清洁，其频率大多为每年二至四次，或以‘足以阻止灰尘积聚或霉菌滋生的频率’进行清洁。第4章702.11部分则对制冰机的消毒做出了规定，要求与冰块接触的表面必须在每次清洁之后进行消毒。”

不按照要求操作的餐厅将被处以巨额罚款。

《食品安全杂志》还提供了消灭人为疏忽的建议，包括洗手、采用冰勺取冰，不要用手直接接触冰块等。

外卖

食品专家对《赫芬顿邮报》表示，有时候冰块污染会导致严重的疾病甚至死亡。不过，你的免疫系统也能很好地解决接触不洁冰块的情况。

FoodSafety.gov网站指出，就食物传染疾病而言，某些特定群体患病的概率都会更高，例如幼儿或老人、艾滋病患者或艾滋病病毒携带者、糖尿病或免疫疾病患者，或是孕妇。

想要避免被污染的冰块，消费者可以关注餐厅和酒吧的清洁度和健康评级。如果你非常在意这点，就别点鸡尾酒，只喝啤酒、红酒、苹果酒，或是只喝一点点。（财富中文网）

译者：严匡正