Considerations in Testing for Residual Solvents
In the dietary supplement and ingredient industry, guaranteeing the safety and quality of products is essential. One important part of quality control is the testing for residual solvents—volatile chemicals used during manufacturing that can pose health risks if not adequately removed.
These solvents, including acetone, ethanol, methanol, and toluene, can have toxicological effects depending on their concentration and type. Some are even known carcinogens, hepatotoxins, or neurotoxins, underscoring the importance of meticulous testing.
The importance of residual solvent testing
Residual solvent testing has two primary goals:
- Consumer Safety – Identifying and mitigating toxic solvents ensure products are safe for consumption
- Regulatory Compliance – Manufacturers must meet guidelines set by regulatory bodies and non-profit organizations such as FDA, USP, and EFSA to uphold industry standards.
Regulatory bodies and non-profit organizations such as the U.S. Food and Drug Administration (FDA), the United States Pharmacopeia (USP), and the European Food Safety Authority (EFSA) have strict guidelines on limits for residual solvents in certain dietary ingredients, drugs, and food products for the purpose of consumer safety.
Through testing, manufacturers demonstrate the safety of their product by meeting safety standards and maintaining product integrity.
Classification of Residual Solvents
There are approximately 60 - 70 different compounds outlined in USP Chapter <467> that are classified into three categories based on their toxicology. These categories include:
- Class 1 solvents: These are the most dangerous solvents with known or suspected along w carcinogens or have ozone depleting characteristics. They must be avoided in pharmaceutical and dietary products.
- Class 2 solvents: Solvents with toxic effects that should be limited.
- Class 3 solvents: The least concerning of the group, these solvents have low toxic potential but should still be controlled.
By adhering to these classifications, dietary supplement manufacturers comply with global regulatory expectations. These testing services help businesses mitigate risks and help guarantee a final product's safety and efficacy.
When residual solvents should be tested
Testing should ideally occur before packaging—but conducting checks earlier in the production cycle can be beneficial. If a particular ingredient may impact the final product, preemptive testing can help manufacturers catch potential issues sooner.
Having an understanding of which solvents are likely present in products can help ensure the appropriate residual solvent screening is conducted to ensure regulatory and consumer safety requirements. This information can often be sourced from vendors or ingredient suppliers to refine testing protocols.
Preparing samples for residual solvent testing
Residual solvents are volatile, meaning they evaporate quickly. To ensure accurate results, proper sample handling is critical:
- Use airtight containers – Prevent evaporation before testing.
- Ship with ice packs – Helps preserve sample integrity during transport.
- Prepare additional samples – Retesting should be performed under identical conditions to avoid discrepancies.
Following these best practices ensures reliable and reproducible test results.
The Eurofins Advantage
With decades of analytical expertise, Eurofins remains a trusted partner in safeguarding product quality. Our rigorous testing methods, industry-leading knowledge, and adherence to global regulatory frameworks provide manufacturers with confidence in their product safety.
By partnering with Eurofins, dietary supplement brands can ensure compliance, mitigate risk, and deliver high-quality products to consumers.
Additional Resources
Prop 65 and Contaminants in Dietary Supplements FAQ
Webinar: Testing of Contaminants and Adulterants in Dietary Supplements
