When this test applies
Chemical characterisation is how endpoints get addressed with data rather than with animals under ISO 10993-1:2025. This particular arm is one cell of a grid — volatility on one axis, solvent polarity on the other. It targets the total mass of non-volatile material the solvent removes, rather than the identity of any single compound, and in isopropyl alcohol (IPA) specifically it is moderately polar organics — many plasticisers, alcohol-soluble antioxidants and their breakdown products, and low-molecular-weight oligomers that come out. IPA covers the middle of the polarity range, and it is the arm that most often turns up the additive package — the compounds a formulator actually put there on purpose.
When to run it
Early, and commissioned as a solvent set rather than one arm at a time — the same extraction campaign supports all of them, and a partial profile usually has to be repeated. Before any of it, get the protocol and the analytical evaluation threshold agreed (GRK-2005): an AET set too high means the study missed things it should have found, and that is a finding a reviewer makes, not you.
What the result gives you
A GLP report giving a single gravimetric figure with the extraction conditions documented, with the extraction conditions documented. NVR is also the readout ISO 10993-18 uses for the exhaustive-extraction stopping rule — successive extractions until the residue falls below threshold — so this figure is what demonstrates the extraction went far enough, one of the first things a reviewer checks.
What it does not settle
A mass tells you how much came off, never what it was. NVR cannot be assessed against a tolerable exposure, because tolerable exposure is per constituent. IPA sits between the extremes and is therefore strongest in the middle: strongly ionic species stay in the water arm and the most lipophilic stay in hexane. IPA also swells some polymers, which raises recovery but means the result is not a simple surface measurement. And chemical characterisation has no independent pass or fail at all: a residue figure carries no safety judgment, and the identification arms are what turn it into something assessable.
Method
Testing per ISO 10993-18:2020/Amd 1:2022. A single extract is prepared in isopropyl alcohol (IPA) at 10 mL, with the extraction ratio per ISO 10993-12: 6 cm²/mL for material under 0.5 mm thick, 3 cm²/mL at 0.5 mm or thicker, or 0.1 to 0.2 g/mL where surface area is indeterminate. The extract is analysed by gravimetric determination.
Where it runs
This analysis is subcontracted to an ISO/IEC 17025 accredited, GLP certified laboratory, and the report is issued under Groenakker cover, in Groenakker’s report template or in your document template on request at no extra cost. Turnaround is 3 to 6 weeks.
Usually ordered alongside
The identification arms in IPA, and the water and hexane residue determinations, which together show how the recoverable mass distributes across the polarity range. And — critically — an ISO 10993-17 toxicological risk assessment to interpret the numbers. Chemistry without the assessment is data without a conclusion; ChemTox bundles the two.
