Storage of Hazardous Chemicals inWarehouses & Drum Stores

Information Sheet November 2012

ScopeThe aim of this guidance is to provide advice on the identification and assessment of risks associated withthe storage of hazardous chemicals in warehouses and drum stores.

For information on the safe storage of laboratory chemicals, please refer to our “Guide on Storage ofHazardous Chemicals in Laboratories”.

These guidelines cover the safe storage of hazardous chemicals that are very toxic, toxic, oxidizing,explosive, flammable (including highly and extremely flammable), dangerous for the environment, waterreactive (i.e. violent reaction with water and toxic gas evolution in contact with water) and corrosive. Thespecific hazardous chemical safety data sheet (SDS) must first be assessed in order to adequately reviewthe chemical properties and associated hazards.

This guidance is specific to packaged chemicals, i.e. chemicals that are packaged in containers of varyingsizes and materials of construction. For example, drums used to store liquids are normally of plastic ormetal construction and range in capacity from 20 litre to 250 litre, while intermediate bulk containers (IBCs)normally have a design capacity of up to 1000 litre. Solids, and in particular, powders may be packaged inbags usually between15 kg to 25 kg in weight and may also be packaged in flexible intermediate bulkcontainers (FIBCs) weighing up to 1000 kg. Pressurised gas cylinders come in wide combination of size,weight and pressure.

Risk Assessment for Storage ofHazardous ChemicalsWarehouses and drumstores that have not been subjectto an adequate hazardous chemical storage assessmentmay have no defined storage system or may have anunsuitable system such as an alphabetical storagesystem. The following is a non-exhaustive list of examplesof inadequate storage systems and practices commonlyfound in warehouses and drum stores;

• Chemicals stored on passageways including forklifttruck routes, other vehicle routes such as truck accessroutes to loading bays, pedestrian walkways etc.

• Absence of a suitable vehicle and pedestrian trafficmanagement plan including defined forklift truckroutes with appropriate speed limits, etc.

• Emergency exits obstructed by chemical containers.

• Chemicals stored on damaged, or inadequatelysecured racking or on damaged pallets.

• Warehouse racking not suitably designed orconstructed to withstand the anticipated loading ofchemical containers placed on it.

• Absence of secondary containment and spillkits.

• Inadequate/no training provided for forklift truckdrivers.

• Where applicable, the absence of a suitablearea for the transfers of chemicals from a largeto smaller packaging, e.g. for production orlaboratory use, batch kitting, etc.

• Cylinders not properly secured against falls.

• Inadequate / no emergency response plan fordealing with chemical incidents such as liquidspills, toxic gas releases or fires.

• Chemicals stored by poorly chosen categories,such as all acids (inorganic and organic, strongoxidizers) together; all organics stored together.

Many of these issues should be addressed byhaving an appropriate chemical inventorymanagement system, which as a minimumincludes an inventory list; this would assist inmonitoring chemical storage practices on aregular basis.

Visual inspections of the chemical and its containershould be carried out on a regular basis and aprocedure put in place for dealing with any issuesthat may be identified such as damage tocontainers, illegible labels, etc.

Safety Data Sheets (SDS) must be readily availablefor all hazardous chemicals stored, and theseshould be referred to for advice on storage,accidental release measures and incompatibilities.

Note: SDS should be supplied in accordancewith REACH Regulation (EC) No. 1907/2006.

All hazardous chemicals being stored should carrycorrect labelling to indicate hazards, according toCLP Regulations (EC) No. 1272/2008.

Segregation Scheme Incompatible chemicals need to be properlysegregated according to the chemical hazard classensuring that like chemicals are stored together andaway from other hazard chemical groups.Segregation in this manner will greatly reduce oreven eliminate accidental adverse reactions thatmay occur due to container breakage in the storageareas. When segregating chemicals by hazard classit is important to ensure that all the hazardousproperties associated with the chemicals areidentified. This information is contained in the SafetyData Sheet (SDS) which the chemical supplier isobliged to provide in respect of hazardouschemicals and can be found in section 2. “HazardIdentification” .

When putting in place the segregation scheme it isimportant to identify all the hazard properties of achemical. Many chemicals have multiple hazardsand a decision must be made as to which storagelocation within the warehouse or drum store is themost appropriate for each individual chemical.Normally the storage area will be determined by themore hazardous property of the chemical andhaving assessed the consequences in the event ofan accident in the storage area. For example if achemical is both flammable and corrosive it wouldbe appropriate for the chemical to be stored withother flammables. However if a chemical is bothflammable and very toxic then other factors need tobe considered before selecting the appropriatestorage area, such as the physical properties of thechemical and the quantity being stored. If thechemical emits very toxic gases or vapours then thechemical may need to be isolated within theflammable storage area. There will always be somechemicals that will not fit neatly in one category oranother, but with a proper identification of thechemical hazards and assessment of consequencesof an accident release using the informationavailable in the SDS, most chemicals should beassigned to appropriate storage areas. In addition tothe SDS there are many industry documents andguidance available on chemical hazard classes,reaction hazards and segregation policies, pleasesee list of references.

Guide on the Storage of Hazardous Chemicals in Warehouses & Drum StoresInformation Sheet

Storage IssuesWhere chemicals are transferred from largecontainers (e.g. 200 L drum or IBC) to smallercontainers (e.g. 20 L drum), the user must ensurethat the relevant hazard information is transferredto the smaller container.

Warehouses and drumstores should havededicated set down areas for incoming chemicalswhere the chemicals containers can be inspectedand associated safety documentation can beretained.

Gas cylinders should be securely stored on a flatdry surface in an adequately ventilated building orpart of a building specifically reserved for thispurpose. Cylinders should be protected fromexternal heat sources that may affect theirmechanical integrity and should be stored suchthat they are not at risk from vehicle impact. Gascylinders should also be stored away from sourcesof ignition and other flammable materials, due tothe potential for explosion.

Secondary containment (e.g. a bunded area)should be put in place to minimize the spread ofany chemical spillage within a storage area, andshould be ideally be designed into the warehouseor drum store at the time of construction. If thestorage area does not have built in secondarycontainment then the use of specialised chemicalcabinets, individual container bunded trays,bunded pallets etc. should be considered.

Racking systems are required to be designed andconstructed by competent persons to ensuresuitability for the anticipated maximum loadingwhich they will be subjected to and should beinspected at appropriate intervals. Damage toracking, such as impact damage caused by aforklift truck, should be immediately repaired orreplaced. Where chemicals are intended to bestacked on top of one another without the use ofracking then a safe maximum stack height must bedetermined, having taken account of the loadbearing capability of the packaging.

FlammablesThe use and storage of flammable chemicalspresents one of the highest hazards in warehousesand drumstores due the risk of fire either by directignition or the fuelling of a fire originating from othersources. A risk assessment in relation to storage ofhighly flammable chemicals may need to becompleted where an explosive atmosphere is likelyto be present or may arise from time to time, and insome cases an Explosion Protection Document(EPD) may have to be prepared. For moreinformation about explosive atmospheres in theworkplace, please refer to Part 8 of the Safety,Health and Welfare at Work (General Application)Regulations S.I. 299 of 2007 titled “ExplosiveAtmospheres at Places of Work.”

Guide on the Storage of Hazardous Chemicals in Warehouses & Drum StoresInformation Sheet

Emergency PreparednessChemical warehouses and drumstores are requiredto have appropriate emergency response and first-aid equipment readily available, and personneltrained in the use of such equipment.

Fire-fighting equipment must be suitable for the firescenarios identified such as flammable liquid,flammable solid, electrical equipment fires, etc.

Emergency response plans are required to beprepared and implemented for accident scenariosinvolving the full range of chemical hazard classesidentified in the storage area, i.e. toxics, oxidizers,explosives, flammables, dangerous for theenvironment, water reactive and corrosivechemicals.

Equipment such as fire extinguishers, first-aidboxes, emergency showers/eye washes should beinspected and tested at suitable intervals andrecords of same maintained.

References/Further InformationBrethericks' Handbook of Reactive ChemicalHazards

Sax's Dangerous Properties of Industrial Materials,Tenth Edition

HSG71 Chemical Warehousing: The Storage ofPackaged Dangerous Substances, available fromHealth and Safety Executive (U.K.) ,www.hse.gov.uk

HSG51 The storage of Flammable Liquids inContainers, available from Health and SafetyExecutive (U.K.), www.hse.gov.uk

EN 14470-1 Safety Cabinets for Flammable andExplosive products, available from the NationalStandards Authority of Ireland, www.nsai.ie

EN 14470-2 Safety Cabinets for Pressurised GasCylinders, available from the National StandardsAuthority of Ireland, www.nsai.ie

Safety, Health and Welfare at Work (GeneralApplication) Regulations, S.I. 299 of 2007 titled“Explosive Atmospheres at Places of Work”, whichis free to download from the Office of the Attorneygeneral website, www.irishstatutebook.ie

HSA Guidance documents “Your Steps to ChemicalSafety” which is free to download from HSAwebsite, http://www.hsa.ie/eng

Further information and advice on chemicals isavailable from the HSA, through a dedicatedChemicals Helpdesk which provides a direct queryservice by e-mail, chemicals@hsa.ie or by phone,1890 289 389.

Guide on the Storage of Hazardous Chemicals in Warehouses & Drum StoresInformation Sheet