Different chemicals can have different levels of purity, and these levels of purity are called “grades”. There are a number of different grades of chemicals which we’ll look at it more detail below, as it’s important to know and understand how these grades differ so that you’ll get the chemical you need for your requirements.
All of these chemical grades are based on accepted measurements, so they are standardised the world over. What you’ll be using the chemical for determines what grade you will need.
The 6 most common grades of chemicals and reagents
This list includes the six grades of chemicals and reagents you’re most likely to come across, ranked from least pure to most pure. Note that just because a chemical is one of the least pure, it doesn’t necessarily mean it’s of low quality.
- Technical grade – used both commercially and industrially, but is not pure enough for food, pharmaceutical, or medical use.
- Purified grade – good quality chemicals that don’t meet an official standard, purified grade is also known as pure or practical grade. Again, it is not pure enough for food, pharmaceutical, or medical use.
- Laboratory grade – often used in labs at educational institutions for teaching purposes, specific impurity levels are unknown in laboratory-grade chemicals. They aren’t pure enough for food, pharmaceutical, or medical use as they contain impurities that would adversely affect these applications. Example: laboratory-grade water
- USP grade – USP-grade chemicals meet or exceed the requirements of the United States Pharmacopeia. The USP covers chemicals used in medicines, food ingredients, and dietary supplements, such as USP purified water which can be used in the manufacture of medical devices.
- Reagent grade – reagent grade chemicals are around 96-98% pure, almost equal in purity to ACS grade (see below). They are used to manufacture food and medicines and are suitable for use in numerous high-purity laboratory and analytical applications.
- ACS grade – ACS-grade chemicals meet or exceed the purity standards as outlined by the American Chemical Society (ACS). These standards are exceptionally high, and ACS-grade chemicals are, like reagent grade chemicals, used to manufacture food and medicines and are suitable for use in numerous high-purity laboratory and analytical applications.
