Emissions

What It Measures

Emissions testing characterises the gases and particles released during charcoal combustion. The species most often measured are carbon monoxide (CO), carbon dioxide (CO₂) and particulate matter (PM), and some protocols add others such as nitrogen oxides (NOx) and volatile organic compounds.

It describes what leaves the fire under the tested conditions — fuel plus appliance plus operating cycle — rather than a fixed property of the fuel alone.

Why It Matters

Emissions affect indoor and outdoor air quality and user safety: carbon monoxide is a particular concern when charcoal is burned in enclosed or poorly ventilated spaces.

Air-quality and product requirements in some markets, and voluntary standards for cookstoves and appliances, are expressed in terms of emission performance. Two charcoals with similar proximate analysis can still differ in emissions, because emissions depend heavily on combustion conditions as well as fuel composition.

Typical Measurement Method

Emissions are measured during a controlled burn. Common approaches include flue-gas analysis with calibrated gas analysers — for example electrochemical or non-dispersive infrared (NDIR) sensors for CO and CO₂ — gravimetric particulate sampling on filters, and standardised sampling trains adapted from stationary-source methods, such as gravimetric particulate and CO methods in the US EPA Method series.

Harmonised protocols for cookstoves define a standard test sequence for emissions and performance; the ISO 19867-1 harmonised laboratory test protocol is the best-known example. Because charcoal emissions depend strongly on the stove, ventilation, fuel charge and operating cycle, the protocol must be reported alongside any result for it to be interpretable.

Buyer Relevance

For markets or applications with air-quality requirements, buyers should ask which species were measured, by which protocol, and under what combustion configuration. A single-species figure reported in isolation does not characterise overall emission performance.

Emission performance is best treated as an application-level property — fuel plus appliance plus operating conditions — assessed alongside, and not instead of, the proximate-analysis parameters reported for the fuel itself.

Limitations

Results are strongly dependent on test configuration, so comparability requires matched protocols; measuring only one species (for example CO) does not characterise overall emissions.

Real-world exposure also depends on ventilation and how the fuel is used, which laboratory testing cannot fully reproduce. This page describes methodology only and states no emissions figures.

Data Source

Public standard methodology (general); not supplier-specific test data.

Last updated: 2026-10-07

Public methods commonly referenced

• ISO 19867-1 — Clean cookstoves: harmonised laboratory test protocols (emissions and performance)
• Flue-gas analysis with calibrated gas analysers (e.g. CO, CO₂, NOx)
• Gravimetric particulate sampling; standardised stationary-source sampling methods (e.g. US EPA Method series)

Standard references are given as general, publicly documented method families. Applicability, current edition and reporting basis must be confirmed with the testing laboratory for any specific report.