The voluntary performance targets provide guidance to benchmark performance of cookstoves. These targets can help stakeholders understand and interpret lab testing results.

The ISO lab testing standard and voluntary performance targets were developed by an ISO technical committee comprised of experts nominated by 45 countries and 8 liaison organizations. They were approved and published in 2018.

There are 5 indicators covered by the targets: thermal efficiency, fine particulate matter emissions, carbon monoxide emissions, safety, and durability. For each indicator, lab test results are rated along 6 tiers (0: lowest performing to 5: highest performing). Tier 0 represents performance typical of open fires and the simplest cookstoves.


Voluntary Performance Targets – Default Values


 Thermal   Efficiency   (%)

 Carbon   Monoxide   Emissions   (gram/megajoule   delivered) 

 Fine Particulate   Matter Emissions   (milligram/megajoule   delivered)

 Safety   (score)    Durability   (score)  
5 ≥50 ≤3.0 ≤5 ≥95 <10
4 ≥40 ≤4.4 ≤62 ≥86 <15
3 ≥30 ≤7.2 ≤218 ≥77 <20
2 ≥20 ≤11.5 ≤481 ≥68 <25
1 ≥10 ≤18.3 ≤1031 ≥60 <35
0 <10 >18.3 >1031 <60 >35


Key considerations about the voluntary performance targets:

  • Voluntary performance targets are meant to be used with results of lab testing as specified by the ISO standard on harmonized lab protocols. Results from other protocols cannot be mapped to this framework.
  • The tiers were not designed to be combined as each indicator is relevant for different impacts.
  • The emissions rates that define tier 5 for fine particulate matter and for carbon monoxide align with the World Health Organization’s Guidelines for indoor air quality: household fuel combustion.
  • The voluntary performance targets for fine particulate matter and carbon monoxide are based on evidence of health risks of exposure to them. If region-specific or country-specific data are available, new tier boundaries for these indicators can be determined.
  • These targets provide guidance but cannot fully predict environment or health impacts as there are many other relevant factors that influence emissions and exposure.