Uncontrolled polymerizations: lessons from accident case studies
Abstract
Runaway polymerization represents a major concern in process safety due to its potential to generate fires, explosions, and toxic releases with severe human and environmental consequences. However, polymerization hazards are not always adequately considered across all operational contexts, particularly beyond reaction systems.
Two principal types of hazardous events are identified through a systematic analysis of accident data: loss of control during an intended polymerization and self-polymerization, the latter occurring primarily during storage and transport. In this study, 90 polymerization-related accidents reported in major international databases were analysed. A total of 26 substances were identified, with styrene emerging as the most frequently involved monomer. Among these, 13 substances were associated with self-polymerization scenarios. These events frequently occur outside reaction systems and are less well accounted for or integrated into risk assessments in these specific contexts.
The causes of these accidents include key triggers specific to polymerization, such as heat exposure, inhibitor depletion, and loss of cooling or stirring. The consequences include releases of hazardous substances, fires, and explosions, often resulting in severe human impacts. The analysis shows that uncontrolled polymerization frequently acts as an initiating event leading to escalation toward loss of containment, fire, explosion, or toxic dispersion.
By distinguishing accident scenarios and linking them to their operational contexts and triggers, this study provides a process-safety-oriented framework for improved hazard identification. The results highlight the need to better account for self-polymerization risks beyond reaction units in safety assessment practices.
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BibTeX
@article{maccarone2026uncontrolled,
title = {{Uncontrolled polymerizations: lessons from accident case studies}},
author = {Daniele Maccarone and Patricia Rotureau and Carlo Adamo and Guillaume Fayet},
journal = {Journal of Loss Prevention in the Process Industries},
year = {2026},
month = sep,
doi = {10.1016/j.jlp.2026.106149},
url = {https://ineris.hal.science/ineris-05739026v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Uncontrolled polymerizations: lessons from accident case studies
AU - Daniele Maccarone
AU - Patricia Rotureau
AU - Carlo Adamo
AU - Guillaume Fayet
PY - 2026
DA - 2026/09/04
JO - Journal of Loss Prevention in the Process Industries
DO - 10.1016/j.jlp.2026.106149
UR - https://ineris.hal.science/ineris-05739026v1
AB - Runaway polymerization represents a major concern in process safety due to its potential to generate fires, explosions, and toxic releases with severe human and environmental consequences. However, polymerization hazards are not always adequately considered across all operational contexts, particularly beyond reaction systems. Two principal types of hazardous events are identified through a systematic analysis of accident data: loss of control during an intended polymerization and self-polymerization, the latter occurring primarily during storage and transport. In this study, 90 polymerization-related accidents reported in major international databases were analysed. A total of 26 substances were identified, with styrene emerging as the most frequently involved monomer. Among these, 13 substances were associated with self-polymerization scenarios. These events frequently occur outside reaction systems and are less well accounted for or integrated into risk assessments in these specific contexts. The causes of these accidents include key triggers specific to polymerization, such as heat exposure, inhibitor depletion, and loss of cooling or stirring. The consequences include releases of hazardous substances, fires, and explosions, often resulting in severe human impacts. The analysis shows that uncontrolled polymerization frequently acts as an initiating event leading to escalation toward loss of containment, fire, explosion, or toxic dispersion. By distinguishing accident scenarios and linking them to their operational contexts and triggers, this study provides a process-safety-oriented framework for improved hazard identification. The results highlight the need to better account for self-polymerization risks beyond reaction units in safety assessment practices.
SN - 0950-4230
ER -