Hazardous and Noxious Substances Spill Incidents

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On this database it is collected information on the fate and weathering of hazardous and noxious substances (HNS) accidentally spilt at the sea around the world. It gathers and systematizes existing information to assist stakeholders involved in spill preparedness and response, and builds return of experience datasheets for the chemicals involved. It will facilitate the incorporation of lessons from past incidents on the decision process to improve preparedness.

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Rest of the world


HNS Spilt

Sodium hydroxideSolid


Amount Spilt (T)490

CAS Number1310-73-2


Physical Behaviour (SEBC code)


Pollution Category (MARPOL Annex 2)


Class according to IMDG code


Subsidiary Risk Class according to IMDG code

Classification as Marine Pollutant


HNS Classification (2010 HNS Convention)

Fate and weathering facts observed/reported

30% soda solution were spilled in Hackensack River and Newark Bay. After the spill, the pH beside the barge was 12, but by 3 hours later it had lowered to 9. Only the area immediately surrounding the barge was affected by the pollution. Recovery was impossible as the chemical immediately dissolved in the water. The spill affected birds, caused the death of fish and destroyed the surrounding marshlands. The possibility of adding weak acid to neutralise the alkali solution was studied, but NOAA recommended the use of fire hoses to increase dilution and to encourage the dissolution of the substance in the water column.

Material Safety Data Sheets (MSDS)