International chemistry relies on a universal understanding of quality, quantities and usages. Groups like the American Chemical Society (ACS) have invested considerable time and energy over several decades to establish standardized chemical grades. Behind the acronyms and definitions lies important categorization that positions laboratory professionals and chemical industry leaders to make exceptional products and informed decisions.
That’s because understanding the purity grades of chemicals is critical to sourcing the correct ingredients for specific applications.
Even experienced professionals discover cost-saving substitutions based on different ACS grades and uses, allowing them to source the perfect specialty chemical ingredients to suit their needs.
Chemical Grade Definitions and Organizing Bodies
The list below is organized from the highest purity grades to the lowest based on the American Chemical Society Committee’s Reagent Chemicals Tenth Edition, commonly called the Online Edition.
ACS (Meets ACS standards)
- Applications: Food, pharmaceuticals. Any high-quality application.
USP (Meets United States Pharmacopeia standards)
- Applications: Pharmaceutical manufacturing, personal care and broad medical use.
NF (Meets National Formulary standards)
- Applications: Pharmaceutical and medical.
Pharmaceutical grade: Approved for pharmaceutical manufacturing and medicinal applications.
Analytical grade: Purity of 95% or more, but the exact standard purity is stated on the product documentation. Typically considered a higher grade than food or laboratory-grade.
Food grade: Approved for use in food, beverage and food-adjacent cleaning applications.
Laboratory grade: High purity, approved for educational or research applications.
Technical grade: Must be checked for laboratory use, typically approved for industrial and manufacturing applications.
Extraction grade: Suitable as a solvent for extraction purposes, primarily in medicinal and botanical applications.
Gradient grade: Suitable for gradient analysis.
It’s important to note that lab, technical or ungraded chemicals are often much less expensive than high-grade chemicals that meet ACS, NF or USP-grade standards. We work with our specialty chemical customers to establish the ideal chemical grade for research or final application use to deliver cost savings without negatively impacting results.
ACS Grade (Reagent Grade)
All ACS-grade chemicals must have purity levels above 95% and technically include pharmaceutical-grade and analytical-grade chemicals, though not all qualifying chemicals are specifically ACS-certified. ACS-grade chemicals have a specific purity standard and testing methodology to ensure quality.
While more expensive, the benefits of using ACS-grade chemicals more than justify the expense in some cases.
These benefits include:
- More accurate results in testing applications.
- Higher-quality products in manufacturing applications.
- Increased reproducibility or more consistent results.
In addition to analytical research and formulation, ACS-grade chemicals are primarily used in pharmaceutical manufacturing and food applications.
USP-Grade Chemicals
Like ACS chemicals, USP grade encompasses all qualifying substances with 95% or higher purity levels. The primary difference between ACS and USP-grade chemicals is their target audience. ACS categorization is preferred in laboratory environments, while USP standards are primarily used in manufacturing environments.
USP-grade chemicals are used in three primary categories:
- Pharmaceutical manufacturing. USP chemicals are the industry standard for drugs, medication and other pharmaceutical products.
- Food additives. Some food additives and dietary supplements require USP-grade ingredients – but not all.
- Quality and safety. USP ingredients are also used to benchmark batched chemical ingredients, serving as reference standards during quality control procedures.
NF-Grade Chemicals
NF-grade chemicals meet National Formulary standards, a certifying body with considerable overlap with the USP. The organizations often release joint advisory papers and classifications, but only some substances covered by the USP are also covered by the NF, and vice versa.
Interestingly, the barriers between NF and USP are largely arbitrary. The entities merged in the 1970s, and there is momentum to eliminate all NF-specific ratings in the future.
As such, NF-rated products are of equal quality as USP and used in pharmaceutical and food applications.
Pharmaceutical-Grade Chemicals
It includes all ACS, USP and NF substances, meaning any pharmaceutical-grade chemical is high quality. Due to overlap between certifying bodies, pharmaceutical substances may also qualify as food grade.
Food Grade vs. Pharmaceutical Grade: What’s the Difference
Both types of chemicals are exceptionally high quality, but the certification process is focused entirely on the end-use application. A chemical earning dual certification has been specifically tested in food and pharmaceutical usages with different criteria.
Food-Grade Chemicals
Food grade denotes any compound designed for safe use in food products during formulation or processing. This includes direct (added to food) and indirect (used in packaging, cleaning or sanitation) additives. Most, but not all, food-grade chemicals meet USP standards.
| Examples of Food-grade Direct Additives | Examples of Food-grade Indirect Additives |
| Acids | Plasticizers |
| Bases | Lubricants |
| Salts | Sanitizers |
| Sugars | |
| Flavorings | |
| Preservatives |
Laboratory-Grade Chemicals
Lab-grade chemicals refer to a wider spectrum of analytical-grade chemicals without strict adherence to the 95% purity level used to categorize the latter. Lab-grade standards vary by manufacturer and application; in some cases, its purity level may not be clearly stated.
Technical-Grade Chemicals
With purity levels below laboratory, food or pharmaceutical grade, technical grade is considered appropriate only for industrial and manufacturing use. Technical grades are less expensive and are typically formulated for specific, high-volume applications such as:
- Textile, plastic, paper and cleaning product manufacturing
- Water treatment facilities
- Mining
- Agriculture
- Oil extraction and refinement
Technical-grade chemicals usually have purity levels between 80% and 90%, although exact standards may vary by manufacturer or end-use application.
Extraction-Grade Chemicals
Extraction chemicals are used as solvents and engineered to improve the performance in safely and efficiently removing the desired substances. The effectiveness of an extraction chemical depends on its molecular composition. Purity is less of a factor in extraction than in other applications, making them less expensive than ACS, USP and NF chemicals.
The New Category: Environmental Grade
This is an ambiguous term in today’s chemical industry. While USP and other bodies provide some information on the environmental impact of chemicals, none officially provide environmental certification or qualification.
Environmental-grade chemicals may refer to any number of manufacturer claims, including:
- Biodegradability
- Recycled content
- Lower toxicity levels
- Reduced emission levels
Any environmental claims should include substantiated evidence and, ideally, third-party verification. To learn more, consult a Tilley Distribution technical representative.
Why Chemical Grade Matters
Chemical categorization helps standardize testing, research and products to ensure safety and quality. For manufacturers, chemical grades offer different price points, flexibility between suppliers and a degree of universality to accelerate new formulations. The inherent overlap between ACS, USP, and NF is important to keep certifying bodies accountable.
Engineer Success … with Tilley Distribution
Tilley Distribution is deeply committed to educating and empowering our suppliers and manufacturing partners. As a leading distributor of specialty chemical ingredients, we are uniquely positioned to supplement your internal efforts and ensure regulatory compliance. Long-term success starts with a conversation. Speak with a Tilley representative today to get started.
