ISO 18188:2016

Overview

ISO 18188:2016 (published as ISO 18188:2015(E)) specifies requirements, test methods and sampling for polypropylene (PP) drinking straws. The standard covers general characteristics, dimensional tolerances and performance tests for PP straws with an inner diameter of 3 mm to 12 mm. It is intended to ensure consistent product quality, suitability for food contact, and reliable performance in beverage and foodservice applications.

Key topics and technical requirements

• Scope and materials
  • Applies to PP drinking straws (straight, flexible/bendable, spoon, sharp-tip, extendable).
  • Raw material must be food-grade polypropylene; any additives (e.g., colorants) must be food-grade. Printing on straws is not allowed.
• Dimensional tolerances
  • Inner diameter: ±0.3 mm of nominal.
  • Length: ±3 mm for nominal ≤ 250 mm; ±5 mm for nominal > 250 mm.
  • Wall thickness: not less than 2% of nominal diameter.
  • Uniformity of wall thickness: max – min < 0.05 mm (colour stripes excluded).
• Performance tests
  • Resistance to bending: bend 90° at five points; no rupture.
  • Heat endurance: immersion in (95 ± 2) °C water, oven at (50 ± 2) °C for 30 min, then inspected for deformation or colour fading.
  • Cold endurance: immersion in (1 ± 1) °C water for 30 min, immediate bending to verify no cracking.
• Inspection and measurement
  • Conditioning per ISO 291; dimensional measurements using specified instruments (profile projector, graduated ruler, devices per ISO 4593).
• Packaging & labelling
  • Packs must keep straws clean; individual wrapping permitted. Packaging must indicate manufacturer, material (polypropylene), size, quantity, manufacture month/year and any buyer-required health/safety information.
• Sampling & conformity
  • Annex A defines lot grouping and sample sizes with acceptance numbers based on lot size (tables for packaging, dimensional and performance testing).

Applications and who uses it

• Manufacturers of PP drinking straws for quality control and product specification.
• Quality laboratories conducting dimensional and endurance tests.
• Procurement and buyers in foodservice, beverage, and packaging sectors to verify supplier conformity.
• Regulators and compliance teams assessing food-contact safety and labeling. ISO 18188 supports consistent production quality, compliance with food-contact requirements and reduced field failures.

Related standards

• ISO 291 (conditioning/testing atmosphere)
• ISO 1873-2 (PP test specimens/properties)
• ISO 4593 (thickness measurement)
• ISO 19069-1 (PP designation/specifications)
• ISO 2859-1 (sampling procedures)

Keywords: ISO 18188, polypropylene drinking straws, PP straws, specification, test methods, dimensional tolerances, bending test, heat endurance, cold endurance, packaging and labelling.