ISO 15011-5:2011

Overview

ISO 15011-5:2011 - Health and safety in welding and allied processes - Part 5 - defines a laboratory method using pyrolysis–gas chromatography–mass spectrometry (pyrolysis‑GC‑MS) to identify thermal‑degradation products produced when welding, cutting, preheating or straightening metals treated with coatings composed partly or wholly of organic materials (shop primers, paints, oils, waxes, adhesives, sealants). The standard is aimed at test laboratories and produces semi‑quantitative chemical data to support safety data sheets (SDS) and occupational hygiene risk assessments.

Key topics and technical requirements

• Principle: heating a small sample in a pyrolyser in an enclosed carrier‑gas flow and identifying degradation products by GC‑MS to concentrate and isolate thermal‑decomposition products.
• Pyrolyser capability: equipment must be able to heat to at least 800 °C. Two common types are filament‑type and oven‑type pyrolysers (Annex B).
• GC–MS system: requires a capillary column in a temperature‑controlled oven, split/splitless injector, mass detector with a typical range (≈25–400 u), and software with library search/peak‑area functions. A non‑polar capillary column (~30 m) with a small internal diameter and film thickness in the ~0.25–0.50 µm range is recommended.
• Sample preparation:
  • Filament pyrolyser: typically a few tens of micrograms (scrapings placed on filament).
  • Oven pyrolyser: typically 0.5 mg to 2 mg loaded into the tube.
  • Oils: extract or dilute in dichloromethane and apply ~2 µl, allowing solvent to evaporate.
• Data analysis & reporting: evaluate and identify compounds of greatest hygienic significance; include test conditions, lot numbers, deviations and semi‑quantitative composition in the test report. Refer to ISO 16000‑6 for guidance on VOC analysis.
• Important limitation: data generated are for identification/semi‑quantification and cannot be used to directly estimate workplace exposure.

Applications

• Identify likely hazardous thermal‑degradation products from weld‑through coatings to:
  • Inform safety data sheets (SDS) and product hazard communication.
  • Define target analytes for subsequent workplace exposure monitoring using quantitative methods.
  • Support occupational hygienists and risk assessors in selecting controls for welding fume and gas hazards.
• Useful for comparative screening of coatings and pre‑testing before full welding trials.

Who should use this standard

• Accredited test laboratories performing fume/gas characterization.
• Coating and paint manufacturers preparing SDS and hazard information.
• Occupational hygienists and health & safety professionals identifying potential thermal degradation hazards from welding operations.

Related standards

• Other parts of ISO 15011 (Parts 1–6) covering fume emission rate, CO/CO2/NO/NO2, ozone, fume data sheets and resistance spot welding procedures.
• Normative reference: ISO 16000‑6 for VOC determination by Tenax sampling, thermal desorption and GC–MS/FID.

Keywords: ISO 15011-5:2011, pyrolysis‑GC‑MS, thermal degradation products, welding fume, coatings, occupational hygiene, safety data sheets.