原文：

This post is part of a series by guest writer Jennifer Chait.

Essential oils are a fairly in depth topic. Basically they’re oils extracted from flowers, plants, grasses, roots, fruits, and leaves. To learn more about the extraction and distilling process visit The International Organization for Standardization.
You can buy essential oils almost anywhere, but your best bet is a specific essential oil shop, a natural food store, or co-op. You want organic 100% pure essential oils. There are tons of synthetics out there. Synthetic oils are ok for scent alone, but don’t hold any real health benefits. The absolute best way to know that you’re buying a brand of pure essential oil is by price. If you see a shelf of essential oils and they’re all the same cost – they aren’t pure. Some essential oils are very expensive to make while others, even pure ones, you can find at a relatively low cost. In any case, if each bottle of oil is $10, move on.
You should also look for dark bottles. Light can ruin the therapeutic benefits of essential oils. Reputable companies almost always bottle their oils in dark glass. Another way to avoid fake oils is to shop with blotting paper. Real oils, contrary to what you may think, are not all that oily. If you drop a few drops of real oil onto your blotting paper it will evaporate and leave no mark. Lastly, once you work with essential oils enough, you’ll be able to tell if an oil is fake by scent alone. Until then you can always buy from a known reputable company like Quinessence Aromatherapy.
Aromatherapy Safety
Whenever you use essential oils you need to dilute them first. In aromatherapy texts, you’ll often see the term, “Carrier oil” or “Base oil” this is the diluter. For example, if you’re going to use lavender to treat a headache, the recipe may say, “Add 2 drops lavender to your carrier oil.” I almost always use sweet almond oil as my carrier. It’s not too expensive, it’s light, but not too light, and has a good scent. You can also try apricot or ask at a natural health store about other options.
One note: if you’re allergic to nuts you cannot use carrier oil made from nuts. This may seem obvious, but I’ve seen a couple people actually use nut oils when they’re allergic. Instead, use a fruit oil, safflower, or sunflower oil instead.
Here are some other key safety tips:
Before you use a new essential oil you should always do a skin test. Dab a drop on your arm, wait a day, and see what happens. Hopefully nothing happens. If you break out, itch, develop a rash, or something else out of the ordinary happens, don’t use that oil. More is not better with essential oils. Essential oils are very powerful and super concentrated. If I see that a recipe calls for 2-3 drops of peppermint, I may try 4 drops but never 10 drops. You never want to overuse oil. The National Association for Holistic Aromatherapy (NAHA) recommends not ingesting oils when you might be able to get the same benefits from massage. There are some treatments that require ingestion or gargling of essential oils, but they’re rare. Unless you know your oils very well, I suggest not ingesting any. Many are toxic when ingested. If you’re pregnant never use oils without the direct advice of a care provider who is well-versed in oils. While many essential oils are good for treating pregnancy issues, some can bring on early labor, and other negative side effects. I always used essential oils with my son, even when he was a baby. However, I always did a skin test first, talked with his pediatrician, and I have experience with oils. In any case it’s good to use smaller amounts of oil for baby treatments, and never leave a bottle out where your young children can reach it. You should call poison control if your child ingests oil. Check back tomorrow for some aromatherapy recipes!
Among other places, you can visit Jennifer Chait at Offbeat Homes, Slices of Green, 7 Babes A Blogging, and Tree Hugging Family.

Miu译文：

精油可算是个有深度的主题。从基本角度来说，它们就是从花卉、植物、草、根、水果及叶子中提取的油。想要了解更多提炼及蒸馏的过程，请登陆网站The International Organization for Standardization（国际标准机构)。
      现在你在哪儿都可以买到精油，但要买上等的还要去专门销售精油的小店，自然食品商店或合作社。你要的是100%的纯精油，可现在到处都是合成的人工制造。就香味而言，人工的是可以了，但它们不具备任何真正的健康价值。最佳的鉴别方法还是看价钱。如果你在店里看到一整排精油都一个价格，那肯定不是纯的。有些精油的制造费相当昂贵，可有些即便是纯的，你也会发现，它们的造价相对要便宜。不管怎么说，要是每一瓶都是10美元，直接走人吧。
      还有就是要选择深色瓶子的。光照射可能破坏精油的治疗效果。可信赖的厂家所生产的产品基本上一贯都是装深色瓶的。还有个避免买假油的方法就是利用吸墨纸。可能你还不知道，大多数精油并不像你想象的那样，其实它们不全都是很油腻的。如果你滴几滴真正的精油在吸墨纸上，他们会立刻挥发，不留痕迹。最后，一旦你接触精油时间长了，你就可以单凭气味分辨真假了。到那个时候，你就可以一直购买到信誉厂家的产品了，比如Quinessence Aromatherapy（克妮赛斯芳疗公司）。
芳疗安全事宜
      每次用精油都记得要先冲淡。在有关芳疗的文章中经常出现“基底油”或“原油”，这个专业术语说的就是稀释剂。举个例子，利用薰衣草芳香治疗头疼时，说明上就可能会说：“在基底油中加入两滴薰衣草精油。”我一般都用甜杏仁做基底油。因为不是很贵，而且浓淡适中，味道也挺好闻的。你也可以试试杏子或让从事自然健康的小店帮你看看别的选择。
      有一点要注意：对坚果过敏的人不能用坚果精油作基底油。虽然听起来是再明显不过的事情，但我确实碰到过有些人在自己过敏的情况下使用坚果精油。可以用水果精油，红花精油或者葵花精油代替。
      以下是其它几点重要安全事宜：
·   每次尝试新的精油前，都要做个皮测。在手臂上滴上一滴，一天后看看有没有一样。最好是没有任何状况。如果突感不适，痒，起疹子或其它非正常反应出现，那就不要用这款精油。
·   精油可不是多多益善的。它们威力很强，而且具有高浓缩度。要是说明上写每天用2-3滴薄荷，我可能用4滴，但绝不会用10滴。使用精油千万不能过量。
·   根据美国国家全身芳疗协会（NAHA)，在可以通过按摩达到治疗效果的情况下，不建议直接服用。有些疗法可能涉及到服用或含漱，但这种情况相当少。除非你非常了解自己的精油，建议绝对不要直接服用。许多精油可在服用后产生毒素。
·   孕妇食用精油必须有明确的指导，指导人对精油十分了解。虽然许多精油有缓解孕期不适的作用，有些可能导致早产以及其它不良反应。
·   从我儿子很小开始，我就给他用精油了。但我总是先做个皮测并且咨询医师。我在精油方面是有经验的。无论怎么说，小孩子用一点精油是有好处的，但绝对不要把整瓶放置在幼儿可触及的地方。
      明天再来看看别的芳疗说明吧！
更多Jennifer Chait的文章，请见Offbeat Homes, Slices of Green, 7 Babes A Blogging, and Tree Hugging Family。