Biocompatibility & Toxicology — Evaluation Within ISO 10993

Biological evaluation of a medical device is a risk-based programme under ISO 10993-1, not a fixed menu of tests. Chemistry, existing data and the device's contact type and duration determine what testing — if any — is actually needed.

Plan the evaluation before ordering tests

The biological evaluation plan reviews materials, manufacturing, chemical characterization and prior data to identify gaps. Cytotoxicity, sensitization and irritation are common endpoints, but the contact category and duration drive the selection. Ordering a standard battery without the plan can waste animals and budget while still leaving regulatory gaps.

Integrate chemistry and toxicology

ISO 10993-18 chemical data and a toxicological risk assessment can address some endpoints without further testing. Agree with the laboratory and assessor which endpoints require in-vitro or in-vivo work and which can be argued from data. Confirm the current editions — for example, irritation is now addressed in ISO 10993-23, separate from sensitization in ISO 10993-10.

Keep responsibilities clear

The laboratory generates study data under its quality system; the manufacturer's evaluator integrates the evidence into the biological evaluation report. Ask how deviations, positive results and equivocal findings are reported, and confirm GLP or other quality expectations where a submission requires them. Laboratory Vortex coordinates requests; it does not evaluate devices.

Start with the biological evaluation plan

Identify direct and indirect body contact, tissue category, duration, finished materials, manufacturing and sterilization residues, and changes from existing evidence. A qualified evaluator decides which endpoints need evidence and whether existing data, chemical characterization or targeted testing can address them. No-contact products and some supported material histories may need different evidence; every device does not need every endpoint.

FDA recognition and guidance status

ISO 10993-1:2025 has partial FDA recognition with exceptions. Declarations to the 2018 edition are accepted for premarket submissions until July 1, 2029; this is a transition, not automatic retesting of all legacy devices. FDA's September 2023 risk-based guidance remains final. Confirm the recognized provisions and evidence needed for the specific submission.

What to include in your buyer brief

Start with the decision the work must support. Unknown details can be clarified after the initial inquiry.

Product, materials/formulation, patient or drug contact, contact duration, intended use and target market; identify changed materials, suppliers or processes.
Finished configuration, sample count and lots, sterilization modality/cycles, aging and storage history; justify worst-case variants and destructive allocations.
Existing evaluation plan, drawings, specifications, methods/editions, previous reports and acceptance criteria; send confidential files only through the private intake.
Required report, quality/accreditation scope, budget range, location, shipping constraints and decision deadline; ask the provider to explain exclusions and subcontracted work.

Reference versus candidate medical plastics and colorants

Compare the reference and candidate finished components, documented resin identity when available, pigment/dye or additive changes, manufacturing and cleaning/sterilization histories, and actual exposure. Unknown composition, sample allocation and test panels remain questions to resolve—not inferred facts. Material identification and color comparison do not establish biological safety.

Propose methods around the evidence gap

Ask the provider whether FTIR, DSC or other material identification, targeted chemistry, extraction studies and toxicological interpretation can answer the comparison question. These are possible proposals, not prescribed tests. Biological compatibility, chemical/material resistance and product interactions are different scopes. A qualified evaluator should justify existing evidence, chemical characterization and any targeted biological testing after a material or colorant change.

Plan, evaluate and test: separate the deliverables

A biological evaluation plan (BEP) identifies contact, duration, existing evidence and gaps; a biological evaluation report (BER) integrates the evidence and rationale. An endpoint laboratory report answers a scoped test question, not the entire biological evaluation. A qualified evaluator should justify endpoint selection and use of prior evidence; not every material change requires every test.

Chemistry versus toxicological interpretation

ISO 10993-18 chemical characterization addresses what substances may be present or released and the analytical coverage/limitations. ISO 10993-17 toxicological risk assessment interprets constituent exposure, toxicological evidence and uncertainty in the device-use context. A chemical list alone is not a safety conclusion, and a TRA cannot cure poorly justified extraction or uncharacterized analytical gaps.

Extractables, leachables and residuals

Forced extractables explore potential release under justified exaggerated conditions; actual or simulated-use leachables address release under relevant contact conditions. Neither automatically substitutes for the other. Distinguish manufacturing residuals such as monomers, solvents and processing aids from sterilization residuals such as ethylene oxide and relevant reaction products. Define analytical targets, exposure assumptions, recovery, reporting thresholds and uncertainties with the provider; no universal panel.

Sample considerations

Provide device description, materials, contact type and duration, and existing test or chemical data.
State the regulatory markets and the stage of the biological evaluation.
Agree endpoints, study designs, sample preparation/extraction conditions and reporting format.

Questions to ask a laboratory

Which endpoints does our evaluation plan still require, and which can chemistry address?
Which ISO 10993 editions will the studies follow?
What quality system applies, and how are deviations and positive results reported?

Laboratories with relevant capabilities

Medical Engineering Technologies (MET) (Dover, Kent) — Biocompatibility Testing
BIOSERV Diagnostics (Rostock, Mecklenburg-Vorpommern) — Biocompatibility Testing
Eurofins Medical Device Testing Munich (Planegg, Bavaria) — Biocompatibility
NAMSA (Northwood, OH) — Biocompatibility
Charles River Laboratories (Mattawan, MI) — Biocompatibility
WuXi AppTec Medical Device Testing (Suzhou, Jiangsu) — Biocompatibility

Frequently asked questions

Which ISO 10993 tests does my device need?: The endpoints follow from the nature and duration of body contact and a documented biological evaluation plan; a laboratory or toxicologist can help scope it before testing.
Can chemical characterisation replace some animal testing?: Chemical characterisation with toxicological risk assessment is widely used to address certain endpoints, and is the approach ISO 10993-18 supports.