Purity describes how much of a material consists of the intended compound rather than other substances or components. For cannabinoid raw materials, purity is often one of the most important indicators of material quality.
Higher purity generally means a larger proportion of the material is the cannabinoid you intended to purchase. However, purity should always be interpreted in context because the remaining fraction is not necessarily unwanted or harmful.
What purity means
Target compound
The purity percentage indicates how much of the material is made up of the intended cannabinoid or other target compound.
Remaining fraction
The remainder can consist of other cannabinoids, related compounds, processing residues, water, solvents or other material depending on the product.
Compare like with like
Purity is most useful when comparing the same type of material. A 90% cannabinoid distillate can meaningfully be compared with a 50% distillate of the same cannabinoid.
Isolates and distillates
Isolate
An isolate is intended to contain almost entirely one compound. For this reason, good cannabinoid isolates commonly have purity values close to 100%.
Distillate
Distillates can contain a much larger remaining fraction. This may include other cannabinoids or related compounds and means purity can vary considerably between products.
Comparing distillate purity
Higher purity distillate
Most of the material consists of the intended cannabinoid, leaving a relatively small remaining fraction.
Lower purity distillate
Only half of the material is the target cannabinoid, so a much larger proportion consists of other components.
When comparing the same cannabinoid and the same type of raw material, a 90% distillate will generally be considered a higher-purity material than a 50% distillate. However, the identity of the remaining fraction still matters.
What makes up the remaining fraction?
Other cannabinoids
A distillate may intentionally contain several cannabinoids. In this case, the remainder is part of the cannabinoid profile rather than unwanted contamination.
Related compounds
Closely related reaction products, isomers or other compounds formed during production may also contribute to the remaining fraction.
Processing residues
Depending on the material and production method, small amounts of solvents, water or other processing-related substances may remain.
The missing percentage should not automatically be described as contamination. A material reported as 70% CBD may, for example, intentionally contain substantial amounts of other cannabinoids.
Purity is not the whole picture
Epimers and stereoisomers
Some cannabinoids can exist in different molecular forms. Two materials can therefore have similar total purity while containing different ratios of those forms.
High purity does not guarantee safety
Even a small remaining fraction can matter if it contains an unwanted or harmful substance. Purity and contaminant testing therefore answer different questions.
Lower purity can be intentional
Full-spectrum, broad-spectrum and anti-crystal distillates are often designed to contain a wider mixture of cannabinoids or other components. A lower percentage of one target cannabinoid can therefore be intentional rather than a sign of poor quality.
HHC is a useful example of why total purity does not tell the entire story. HHC can contain different 9R and 9S forms, and the ratio between these forms can vary even when total HHC purity is similar.
Why purity matters
Material quality
When comparing similar raw materials, higher purity generally indicates that a larger proportion consists of the intended compound.
Concentration
Higher-purity material provides more of the target cannabinoid in the same amount of raw material.
Formulation accuracy
Knowing the actual purity makes it possible to calculate how much target compound is introduced into a formulation.
Batch consistency
Consistent purity between batches helps keep formulations and analytical results more predictable.
Value assessment
Price alone can be misleading. A cheaper low-purity distillate may contain substantially less target cannabinoid per gram than a more concentrated material.
Product specification
Purity provides a measurable specification that can be checked between suppliers, batches and laboratory reports.
Assessing purity in practice
Check the COA
Use a laboratory report to confirm the measured concentration of the target cannabinoid rather than relying only on the product description.
Identify what is being measured
Confirm whether the reported percentage refers to one specific cannabinoid, total cannabinoids or another combined measurement.
Compare the same material type
Compare isolate with isolate and similar distillates with each other. A broad-spectrum or anti-crystal product should not be judged using the same expectations as a single-compound isolate.
Look at the remaining composition
Check whether the COA identifies other cannabinoids or compounds that explain part of the remaining percentage.
Check specific forms when relevant
For compounds where epimer or stereoisomer ratios matter, total purity alone may not provide enough information to compare two materials properly.
As a practical rule, higher purity is usually preferable when comparing equivalent single-compound raw materials. The product type, intended composition and identity of the remaining fraction should always be considered before deciding which material is higher quality.