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 water specifically it is salts, acids, residual monomers carrying polar functionality, water-soluble process aids such as surfactants and polyethylene glycols, and hydrolysis degradants that come out. Water is the polar extreme and the closest analogue to the aqueous physiological environment, so a finding here is the one most directly relevant to a patient-contacting surface.
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. Water barely touches the lipophilic end of the profile. Slip agents, hydrocarbon oils and phthalate-type plasticisers can be present in quantity and still not appear here, which is why the hexane arm exists. 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 water 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 water — semi-volatile and non-volatile — because a residue figure only becomes assessable once the compounds behind it are named. Total organic carbon (GRK-2018) is the closely related aqueous bulk measure. 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.
