EN 16738:2015

Overview

EN 16738:2015 - "Emission safety of combustible air fresheners - Test methods" (CEN) defines a standardized chamber test method to quantify emissions from combustible air fresheners (e.g., scented candles, oil lamps, catalytic lamps, incense) into indoor air. The method is performed in a dynamic emission test chamber according to EN ISO 16000‑9 and is designed to minimize test-induced effects on combustion. EN 16738:2015 targets volatile and combustion‑generated pollutants such as VOCs, benzene, naphthalene and formaldehyde, with optional measurement guidance for SO2, NOx and CO. It is not suitable for quantitative measurement of particulate matter and excludes non‑combustible air fresheners and loose incense; scented candles with burning time < 2.5 h are outside the scope.

Key topics and requirements

• Test principle: Determine the unit specific emission rate (SERu) using chamber outlet concentrations, air change rate (n) and number of specimens (N), assuming a fully mixed chamber.
• Apparatus: Dynamic environmental emission test chamber per EN ISO 16000‑9 and wire mesh cylinders type 2 (EN 15426) for specimen placement.
• Standard test conditions:
  • Chamber volume: 1.0 m3 ± 0.1 m3 (larger chambers allowed only with validation).
  • Inlet air: 23 °C, 50% RH, 2 air changes per hour (≈2.0 ± 0.2 h‑1).
  • Temperature, relative humidity and oxygen concentration must be controlled; draught‑free, stable burning is required.
• Specimen setup and sampling:
  • Positioning rules for scented candles, oil lamps, incense and catalytic lamps (wire mesh cylinder distances, spacing, stands).
  • Typical sampling durations and specimen counts (e.g., scented candles: normally 2 specimens inside the chamber, sampling time ≈ 60 min; table provides different protocols for candles ≥4 h, 2.5–4 h, incense, oil and catalytic lamps).
• Analytes: Mandatory focus on VOCs, benzene, naphthalene, formaldehyde; method can be adapted to other substances. Optional guidance for SO2, NOx, CO.
• Limitations: Not intended for particulate matter quantification; excludes non‑combustible products and short‑burn candles (<2.5 h).

Applications and users

EN 16738:2015 is practical for:

• Product manufacturers (candles, oil lamps, catalytic lamps, incense) validating emission performance and safety.
• Testing laboratories conducting standardized chamber emission tests and producing SERu data.
• Regulators and certification bodies setting indoor air safety criteria and compliance programs.
• Product designers and formulators optimizing fragrances and fuels to reduce hazardous combustion by‑products.
• Retailers and procurement teams seeking verified emissions data for consumer safety claims.

Using EN 16738 supports consistent, comparable emission data for indoor air quality assessments, ingredient selection and regulatory reporting.

Related standards

Key referenced standards include:

• EN ISO 16000‑9 (chamber method for VOC emissions)
• ISO 16000‑6 / ISO 16000‑3 / EN ISO 16017‑1 (VOC and carbonyl sampling/analysis)
• EN 15426 (candles - sooting behaviour and wire mesh cylinders)
• Emission reference methods for NOx, SO2, CO and O2 (EN 14211, EN 14212, EN 14626, EN 14789, EN 14792, EN 15058)

Keywords: EN 16738:2015, emission safety, combustible air fresheners, chamber test, VOC, benzene, formaldehyde, scented candle testing, indoor air.