When this test applies
ISO 10993-1:2025 makes chemical characterisation to ISO 10993-18 the starting point of a biological evaluation for prolonged and long-term contact devices, and the preferred route to the systemic, genotoxicity and carcinogenicity endpoints wherever good extractables data can replace an animal study. Non-volatile residue is the mass-balance check on the extraction: it says how much came out in water, independent of what the compounds are, and it is the quantity the exhaustive-extraction stopping rule in ISO 10993-18 is written against.
When to run it
At the start of an exhaustive-extraction programme, and alongside the compound-specific screens in the same solvent. A high NVR with a short compound list is the signal that the screens are missing something and the method needs attention.
What the result tells you
The mass of residue left after the water extract is evaporated, reported per device or per unit area. Under the ISO 10993-18 stopping rule, extraction continues until a step yields no more than 10% of the residue recovered in the first. There is no independent pass or fail.
What it does not tell you
Nothing about what the residue is — identification and quantification are the job of the VOC, SVOC and NVOC screens — and nothing about volatiles, which are lost on evaporation. Chemical characterisation has no independent pass or fail: the data mean nothing until a toxicologist reads them against exposure under ISO 10993-17, and the screen cannot see compounds the solvent did not extract or the technique cannot detect.
Method
Testing per ISO 10993-18:2020/Amd 1:2022. The sample is extracted in water, the extract is evaporated to dryness under controlled conditions and the residue is weighed on an analytical balance against a solvent blank. Extraction ratio follows 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.
Where it runs
Testing is performed to Groenakker protocols at an ISO/IEC 17025 accredited laboratory in Groenakker’s network, and the report is issued under Groenakker’s ISO 13485:2016 certified quality system, in Groenakker’s report template or in your document template on request at no extra cost.
Usually ordered alongside
The other screens that make up a complete extractables profile — VOC, SVOC, NVOC and heavy metals across the three solvents — then the toxicological risk assessment (GRK-2001) that turns the compound list into a conclusion. The ChemTox packages bundle all of this for one price.
