user8107: During my college humanities class, I learned some things about Buddhism, which I had not had exposure to before. My teacher would sometimes tell us stories about field trips he would take with the class to a local Buddhist temple. In one such story, he said that he asked the cute Buddhist that worked at the temple if Buddhists were allowed to use antibacterial soap. 
From his story, she apparently didn't find that very funny, but he was left without an answer. 
I understand that Buddhist's are not allowed to kill. Does this include microscopic living organisms that would be alive on your hands? In other words, what is the answer to his question, "Can Buddhists use anti-bacterial soap?"

user8586: The bodhisattva precepts forbid the killing of "sentient beings". Bacteria is not sentient so I see no problem with using antibacterial soap. It is also rather difficult to avoid killing bacteria through daily living. So, it would be extreme, if not impossible, to try to kill all bacteria around you.

user10304: 
I understand that Buddhist's are not allowed to kill.

This is a general misunderstanding, or lack of correct understanding in this Buddhist notion. It contains at least two aspects: a) due to compassion, killing should be forsaken which is against compassion. b) killing will produce bad effect, it won't solve the problem, for a harmful action won't produce good result, as a poisonous tree can't produce eatable fruit. 
So,

Can a Buddhist use antibacterial soap?

It's not really the big deal, or the main issue. The issue is antibacterial soap won't help in eliminating contamination, or benefit health (consider notion b). because the bacterial will evolve and become anti-antibacterial, we see this in medical reports. Likely antibacterial soap is also a marketing gimmick too, like toothpaste for man, toothpaste for woman, for kids, baby girls... etc. 
If one wants to be healthy and not infected, it's not to use antibacterial soap, it's to build up one's physical strength, health condition, becomes immune to any disease or infections. During the Black Death, many died, but some survive, why? During SARS, a patch died, but some were immune instead some even carriers of the virus, why? Buddha has the answer but it would be too off (too advance?) for modern men they can only label it: superstitions.     

user289: In Mahayana, the key distinction is sentient beings vs non-sentient beings. So plants and bacteria would be non-sentient beings and there would not be a violation of the first precept. And eating bacteria wouldn't be a violation of the 3rd minor precept. I'd note that in the linked translation, the 1st precept also is qualified by "sentient beings".
It is also worth nothing that Buddhism is not a homogeneous thing with homogeneous followers, so over time people and Buddhists have learned more about science and had to react to it. Sometimes this means ancient science got incorporated into the religion, such as beliefs/theories about the biological mechanisms of reproduction, or theories about circulation in the body. As a modern Buddhist, I'd dispense with the ancient, incorrect science and think about what ancient Buddhist would have said about biology if they were better informed with modern science. (And I'm not talking about science vs religion here, I'm talking about, what if ancient thinkers knew about bacteria and the cognitive capacities of bacteria)  I think they would deem bacteria insentient and incapable of suffering.
I don't know why the lady at the temple didn't like the question. If it was a Mahayana temple, reasonable chance they felt they were being mocked for following a silly rule. The person asking the question was a half step away from asking "To what extremes would you go to practice your silly religion?" or another common subtext when the topic is nitpicky rules "Gee, you must think you're so much better than us people who use anti-bacterial soap"
If this was a Shin temple, strict following precepts is a waste of time, only faith in the power of Amida will show results. In that case, the lady was just annoyed that the guy did the equivalent of going to a Christian Church and asking what Christians have against eating pork and why Christians wear 
Burkas and why they worship cows.
UPDATE. This is an American/Vietnamese temple, which appears to be a mix of immigrant and non-immigrant Buddhism, crossing Zen, Vajrayana, Mahayana, but mostly Mahayana. In this context, bringing up bacterial soap means you want to either agree with someone about vegetarianism or fight with them about it. So if you aren't confrontational, you don't fight with them about it. The stats on vegetarianism among American Buddhists is dodgy, but is ballpark of ~25% which is ten times higher than the general population (give me a specific sect and that can be adjusted higher or down to nearly 0-- non-Japanese East Asian Buddhism is pro-vegetarian, the rest are anti-vegetarian). By the way, if this whole question is about vegetarianism, refer to the pre-existing questions & answers. 
Speaking of pre-existing answers, this question about the status of bacteria has been asked before.

user295: There istance a monk with psychic ability looked into the water and saw there were microbes and asked the Buddha if drinking will harm them. Buddha said don't look and drink.
One intention of Buddhist morality is the stabilize the mind so it is free from remorse and so it can develop concentration and wisdom. 
So if you use antibacterial soap without much thought there are microbs and intention of killing microbes then there will be not issue.

8107: <p>During my college humanities class, I learned some things about Buddhism, which I had not had exposure to before. My teacher would sometimes tell us stories about field trips he would take with the class to a local Buddhist temple. In one such story, he said that he asked the cute Buddhist that worked at the temple if Buddhists were allowed to use antibacterial soap. </p>

<p>From his story, she apparently didn't find that very funny, but he was left without an answer. </p>

<p>I understand that Buddhist's are not allowed to kill. Does this include microscopic living organisms that would be alive on your hands? In other words, what is the answer to his question, "Can Buddhists use anti-bacterial soap?"</p>
 8586: <p>The bodhisattva precepts forbid the killing of "sentient beings". Bacteria is not sentient so I see no problem with using antibacterial soap. It is also rather difficult to avoid killing bacteria through daily living. So, it would be extreme, if not impossible, to try to kill all bacteria around you.</p>
 10304: <blockquote>
  <p>I understand that Buddhist's are not allowed to kill.</p>
</blockquote>

<p>This is a general misunderstanding, or lack of correct understanding in this Buddhist notion. It contains at least two aspects: a) due to compassion, killing should be forsaken which is against compassion. b) killing will produce bad effect, it won't solve the problem, for a harmful action won't produce good result, as a poisonous tree can't produce eatable fruit. </p>

<p>So,</p>

<blockquote>
  <p>Can a Buddhist use antibacterial soap?</p>
</blockquote>

<p>It's not really the big deal, or the main issue. The issue is antibacterial soap won't help in eliminating contamination, or benefit health (consider notion b). because the bacterial will evolve and become anti-antibacterial, we see this in medical reports. Likely antibacterial soap is also a marketing gimmick too, like toothpaste for man, toothpaste for woman, for kids, baby girls... etc. </p>

<p>If one wants to be healthy and not infected, it's not to use antibacterial soap, it's to build up one's physical strength, health condition, becomes immune to any disease or infections. During the Black Death, many died, but some survive, why? During SARS, a patch died, but some were immune instead some even carriers of the virus, why? Buddha has the answer but it would be too off (too advance?) for modern men they can only label it: <em>superstitions</em>.     </p>
 289: <p>In Mahayana, the key distinction is sentient beings vs non-sentient beings. So plants and bacteria would be non-sentient beings and there would not be a violation of the first precept. And eating bacteria wouldn't be a violation of the <a href="http://www.fodian.net/world/1484.html" rel="nofollow">3rd minor precept</a>. I'd note that in the linked translation, the 1st precept also is qualified by "sentient beings".</p>

<p>It is also worth nothing that Buddhism is not a homogeneous thing with homogeneous followers, so over time people and Buddhists have learned more about science and had to react to it. Sometimes this means ancient science got incorporated into the religion, such as beliefs/theories about the biological mechanisms of reproduction, or theories about circulation in the body. As a modern Buddhist, I'd dispense with the ancient, incorrect science and think about what ancient Buddhist would have said about biology if they were better informed with modern science. (And I'm not talking about science vs religion here, I'm talking about, what if ancient thinkers knew about bacteria and the cognitive capacities of bacteria)  I think they would deem bacteria insentient and incapable of suffering.</p>

<p>I don't know why the lady at the temple didn't like the question. If it was a Mahayana temple, reasonable chance they felt they were being mocked for following a silly rule. The person asking the question was a half step away from asking "To what extremes would you go to practice your silly religion?" or another common subtext when the topic is nitpicky rules "Gee, you must think you're so much better than us people who use anti-bacterial soap"</p>

<p>If this was a Shin temple, strict following precepts is a waste of time, only faith in the power of Amida will show results. In that case, the lady was just annoyed that the guy did the equivalent of going to a Christian Church and asking what Christians have against eating pork and why Christians wear 
Burkas and why they worship cows.</p>

<p><strong>UPDATE</strong>. This is an American/Vietnamese temple, which appears to be a mix of immigrant and non-immigrant Buddhism, crossing Zen, Vajrayana, Mahayana, but mostly Mahayana. In this context, bringing up bacterial soap means you want to either agree with someone about vegetarianism or fight with them about it. So if you aren't confrontational, you don't fight with them about it. The stats on vegetarianism among American Buddhists is dodgy, but is ballpark of ~25% which is ten times higher than the general population (give me a specific sect and that can be adjusted higher or down to nearly 0-- non-Japanese East Asian Buddhism is pro-vegetarian, the rest are anti-vegetarian). By the way, if this whole question is about vegetarianism, refer to the pre-existing questions &amp; answers. </p>

<p>Speaking of <a href="https://buddhism.stackexchange.com/questions/1397/buddhism-and-bacteria">pre-existing answers, this question about the status of bacteria has been asked before</a>.</p>
 295: <p>There istance a monk with psychic ability looked into the water and saw there were microbes and asked the Buddha if drinking will harm them. Buddha said don't look and drink.</p>

<p>One intention of Buddhist morality is the stabilize the mind so it is free from remorse and so it can develop concentration and wisdom. </p>

<p>So if you use antibacterial soap without much thought there are microbs and intention of killing microbes then there will be not issue.</p>
