ISO 22947:2019

Overview

ISO 22947:2019 specifies a laboratory method for measuring carbon monoxide (CO) in the vapour phase of cigarette smoke obtained under an intense smoking regime, using a non‑dispersive infrared (NDIR) analyser. The standard defines apparatus, calibration, sampling, measurement procedures and result expression so that CO yields can be reported as volume or mass per cigarette.

Key topics and technical requirements

• Scope and principle: Collection of vapour phase from cigarettes smoked on a routine analytical smoking machine (intense regime) and quantification of CO by NDIR.
• Apparatus: conditioning enclosure (ISO 3402), routine analytical cigarette‑smoking machine (ISO 20778), vapour‑phase collection system (bags or containers), NDIR analyser, ignition device, barometer and thermometer.
• Collection system: impermeability check (4–6% CO test gas) with maximum drift of 0.2% CO after 2 hours; bag volumes sized so final pressure ≈ ambient (practical: ~3 L for 3 cigarettes, ~10 L for 10 cigarettes).
• NDIR analyser performance: preferred working range 0–10% CO; sampling rate 0.5–5 L/min; precision ~1% full scale; linearity ~1% full scale; repeatability ~0.2% full scale; minimal cross‑response to water vapour.
• Calibration and gases: use nitrogen make‑up gas of high purity. Calibrate with at least three certified CO-in-nitrogen mixtures (typical ~1%, 3%, 5%) within a relative error of 2%. Recalibrate at least weekly and verify before measurements.
• Procedure: conditioning of test cigarettes, warm‑up and zeroing of analyser, evacuation/flushing of collection device, smoking per ISO 20779/ISO 20778 intense regime, sampling through NDIR analyser, and calculation of average CO per cigarette (volume and mass).
• Reporting and quality: includes repeatability/reproducibility data and required test report content (sample identification, sampling, measurement conditions, results).

Applications and who uses it

• Analytical laboratories measuring cigarette emissions for product characterization.
• Tobacco manufacturers conducting product testing and design verification.
• Regulatory authorities evaluating compliance and comparative emissions under an intense machine smoking regime.
• Researchers studying smoke chemistry and emission factors. Practical uses include emission profiling, product development, interlaboratory comparisons and inputs to hazard assessment. Note: ISO 22947:2019 - like other machine smoking standards - is not a direct measure of human exposure or risk and should be interpreted accordingly.

Related standards

• ISO 20778 - definitions and conditions for an intense smoking regime
• ISO 20779 - generation and collection of total particulate matter (vapour/particulate separation)
• ISO 3402 - conditioning atmosphere for testing
• ISO/TR 19478 series - interlaboratory study background

Keywords: ISO 22947:2019, cigarette CO measurement, NDIR method, intense smoking regime, vapour phase, cigarette-smoking machine, calibration gas mixtures.