Since late 2023, Houthi forces in the Red Sea have evolved from a local insurgency to a sophisticated non-state actor, using missiles and armed drones to extend their reach, impose strategic costs and challenge regional maritime security. In parallel, maritime security in the Bab el-Mandeb Strait is a uniquely sensitive chokepoint — one of the world’s major oil corridors — where attacks on shipping can cascade rapidly into broader supply-chain disruption.
Within this environment, the most credible chemical, biological, radiological and nuclear (CBRN) defence pathway is not deliberate employment of banned chemical agents but a secondary chemical release: a conventional strike that ruptures platforms carrying toxic industrial chemicals (TICs). TIC releases — accidental or attack-induced — are core chemical hazards because their clinical effects, decontamination needs and operational consequences can mirror those of chemical-warfare exposure. Accordingly, Houthi drone warfare in the Red Sea should be analysed not primarily as a chemical-weapons problem but as an escalating driver of CBRN industrial risk with potential humanitarian and strategic fallout.
Industrial disasters as strategic signals
Two recent catastrophes demonstrate the scale of potential secondary chemical effects. The Aqaba chlorine release of 27 June 2022 shows how quickly routine port activity can become a chemical mass-casualty event. A pressurised container of liquefied chlorine fell during loading, ruptured and resulted in 13 deaths and more than 250 injuries. Process-safety assessments highlight chlorine’s high toxicity, dense-gas behaviour that keeps plumes close to the ground, and oxidising nature, all of which amplify hazards for responders and nearby populations even when releases are brief. Ports function as chemical amplifiers: hazards are embedded in everyday cargo, so containment failure can produce CBRN-relevant effects without any chemical weapon being used.
Beirut 2020 reinforces the same logic at a larger scale. Reconstructions document that roughly 2,750 tonnes of ammonium nitrate detonated after a warehouse fire, producing one of the largest non-nuclear explosions of the modern era. The blast killed more than 200 people, injured thousands, and caused extensive urban damage. The catastrophe was caused by improperly stored industrial chemicals. Together, Aqaba and Beirut demonstrate a potential critical pattern for the Red Sea theatre: where high-volume toxic or reactive cargo is present, conventional attacks on ships or coastal facilities can trigger secondary chemical incidents whose humanitarian and strategic effects could rival those of deliberate CBRN attacks.
Coastal sea-denial
For Red Sea security, the key implication is the increasing probability that conventional strikes intersect with hazardous industrial cargo or coastal chemical infrastructure, thereby setting the conditions for secondary chemical (CBRN-C) incidents.
Emergency medicine and humanitarian doctrine treat TIC exposure — chlorine, ammonia, acids, solvents, and similar substances — as part of the chemical CBRN spectrum because the pathophysiology and response demands resemble chemical-weapon incidents. Catastrophic chemical harm does not require militarised agents; high-volume industrial chemicals moving through ports and coastal clusters can produce severe outcomes once containment is compromised. The Aqaba incident demonstrated how rapidly dense-gas TIC plumes can overwhelm response systems, while dispersion modelling confirms that such clouds can spread quickly in open environments, creating acute near-field and down-wind hazards. Applied to the Red Sea, this means a drone or missile strike on a chemical tanker, a coastal storage terminal or an industrial port node could generate a secondary chemical emergency even if the payload is purely conventional.
Plausible pathways
Several realistic scenarios illustrate this dynamic. First, a one-way UAV or missile strike on a chemical tanker transiting Bab el-Mandeb could breach a tank carrying chlorine, ammonia, methanol or similar TICs. In narrow, high-density sea lanes, even a single breach may release a dense toxic plume or ignite volatile cargo, forcing coastal evacuation, halting port operations and temporarily closing the chokepoint.
Second, a strike on an LPG/LNG carrier or refined-fuel tanker could yield a multi-hazard scene that combines large-area fire, toxic combustion products and secondary chemical exposure for crews and nearby coastal populations, with immediate disruption to shipping schedules and insurance risk.
Third, an attack on ship-shore chemical infrastructure — ports, tank farms or loading arms — could generate rapid secondary release because storage volumes are high and failure modes cascade quickly; a conventional strike on coastal tanks holding acids, ammonia or other TICs could paralyse a terminal in ways operationally analogous to Aqaba.
Finally, a strike that initiates sustained fire near fertiliser or nitrate storage areas could produce a ‘mini-Beirut’ pathway: while replicating Beirut’s scale would be rare, fertilisers and nitrate-based products remain common in maritime trade, and attack-induced fire in their vicinity could lead to high-consequence industrial explosions with toxic by-products and prolonged port closure.
These scenarios show why Red Sea security is now inseparable from CBRN-chemical preparedness; the Houthis do not need chemical weapons to create chemical mass-casualty outcomes in an area saturated with hazardous industrial cargo.
Land-based exposure
Secondary chemical risk is also land-based. The western Saudi littoral concentrates major coastal industrial zones that store and process substantial TIC inventories, making shore facilities potential chemical amplifiers if struck. Yanbu Industrial City is a prominent Red Sea hub for crude-oil and natural-gas refining and petrochemical production, with extensive port-adjacent storage of fuels, solvents, acids and other hazardous substances. The Rabigh corridor hosts large refinery-petrochemical complexes whose industrial footprint and associated chemical handling are well documented. Jeddah adds a third land-based exposure point because heavy industrial and logistics activity is concentrated close to densely populated coastal districts.
A second category of shore-side vulnerability is desalination infrastructure. Red Sea desalination plants are central to Saudi and regional water security and routinely store chlorine and other hazardous dosing chemicals onsite to control biofouling and corrosion. Physical damage to these systems could therefore trigger localised TIC releases even under purely conventional attack conditions. Recent analyses of the Red Sea crisis emphasise that widening Houthi sea-denial operations increase the chance of strikes, mis-targeting or spillover near coastal infrastructure, reinforcing the credibility of land-based secondary-release scenarios.
Regional implications: Trade, energy and CBRN readiness
For Middle Eastern littoral states, these dynamics translate into immediate economic shocks and longer-term preparedness demands. Traffic through the Red Sea–Suez route fell sharply in early 2024. When Bab el-Mandeb and Suez flows are constrained, shipping diverts via the Cape of Good Hope, increasing transit times, insurance premiums and supply-chain costs that feed inflationary pressure for regional importers and exporters. Energy and petrochemical exporters on the Red Sea, especially Saudi Arabia, face a dual risk: higher logistics and insurance costs and the possibility that conventional strikes trigger secondary TIC releases at sea or in coastal industrial zones, forcing temporary port shutdowns. Because these outcomes can occur without chemical-weapons use, the crisis elevates CBRN readiness — TIC detection, HazMat firefighting and integrated civil-military response — to a frontline requirement for ports, refineries and desalination nodes.
This feature appeared in issue 68 of Fire Middle East magazine.
