ISO 4906:2024

Overview - ISO 4906:2024 (Filling power for fine‑cut tobacco)

ISO 4906:2024 specifies a laboratory method to determine the filling power of tobacco used for fine‑cut smoking articles (FCSAs) using a constant‑weight pressurization technique. The filling power quantifies the volume occupied by a unit mass of fine‑cut tobacco after exposure to a defined load and time. This physical property influences manufacturing, product quality and tobacco utilization in rolled and hand‑made smoking articles.

Key topics and technical requirements

• Principle: place a defined mass of conditioned fine‑cut tobacco in a measuring cylinder, apply a constant load for 30.0 s, then measure the compressed column height to calculate filling power.
• Apparatus requirements:
  • Measuring cylinder: inner diameter (60.0 ± 0.1) mm; height ≥ 100 mm.
  • Measuring/loading head: internal diameter 55.0–57.0 mm; uniform 20 N load.
  • Lowering speed: (19 ± 1) mm/s.
  • Height sensor: 0.01 mm accuracy, repeatability ≤ 0.03 mm.
  • Balance: resolution 0.01 g.
• Sampling & conditioning: laboratory sample ≥ 500 g; sampling per ISO 15592‑1; condition and test atmosphere per ISO 15592‑2. Determine water content by ISO 6488 (Karl Fischer) or ISO 16632 (GC).
• Test procedure: five determinations per test sample (10–15 g each); report individual values to 0.01 cm3/g; final result is the arithmetic mean of five runs.
• Calculation: filling power P = (π r^2 h) / m (reported in cm3/g), where r is cylinder radius, h is compressed height and m is sample mass.
• Precision data: collaborative study (11 labs) produced repeatability limits r ≈ 0.05–0.08 cm3/g and reproducibility limits R ≈ 0.23–0.26 cm3/g (relative variability ~1.5–1.8% r and 4.7–6.6% R depending on tobacco type).
• Test report content: sample ID, date, test atmosphere (RH, °C), water content, measuring head size, average/min/max/CV and number of determinations.

Applications and who uses it

ISO 4906:2024 is intended for:

• Quality control laboratories in tobacco manufacturing and processing.
• R&D teams developing fine‑cut blends and FCSAs (hand‑rolling and machine‑made).
• Suppliers and purchasers assessing bulk handling, packing and volumetric yield.
• Regulatory or standards bodies comparing physical characteristics of tobacco products.

Practical benefits include standardized measurement of packing behavior, optimized filler use in production, consistent product specifications and better comparability across labs.

Related standards

• ISO 15592‑1, ISO 15592‑2 (sampling, conditioning, test atmosphere)
• ISO 6488, ISO 16632 (water content methods)
• ISO 15592‑3 (related analytical methods)
• ISO 5725‑5 (statistical evaluation of precision data)

Keywords: ISO 4906:2024, filling power, fine‑cut tobacco, constant‑weight pressurization, tobacco testing, tobacco quality control.