Total Hydrocarbon (THC) Residue Determination on Medical Devices

Pre-Treatment: Solvent Extraction • Determination: Gravimetric Method
According to TS EN ISO 9377-2 Annex C

1. What is THC Residue?

Total Hydrocarbon (THC) refers to residual oil, grease, lubricants or organic hydrocarbon contaminants that remain on the surface of medical devices during production, assembly or cleaning.

These residues may:

• Interfere with sterilization,

• Cause cytotoxicity or inflammation (ISO 10993-1),

• Lead to regulatory non-compliance.

2. Applicable Standard: TS EN ISO 9377-2 Annex C

This standard defines the determination of extractable petroleum hydrocarbons. Annex C allows gravimetric determination, which is suitable for medical device cleanliness validation.

3. Sample Preparation – Extraction

4. Gravimetric Determination Procedure

1. Weigh a clean evaporation dish (m₀)

2. Transfer the extract

3. Evaporate solvent at 105 °C

4. Weigh remaining hydrocarbons (m₁)

5. Calculate:

$$THC\\,(mg/device) = \\frac{(m₁ - m₀)}{number\\, of\\, devices}$$

5. Acceptance Criteria

6. TTS Laboratory Services Support

✔ Residual hydrocarbon testing per ISO 9377-2 Annex C
✔ Gravimetric + GC-FID/GC-MS confirmation
✔ ISO 10993-17 toxicological evaluation
✔ ISO 13485, CE, FDA compliant reporting
✔ Cleaning validation and contamination control