Most active research labs will have chemicals in use; from the common (e.g. ethanol, bleach, isopropanol), to those that are highly hazardous on their own (e.g. t-butyllithium, perchloric acid, dichloromethane), to those that become even more hazardous when combined with other chemicals, with time, or with poor storage conditions (e.g. peroxide formers, strong oxidizers.)  

It is vitally important that everyone working in or around Johns Hopkins research laboratories be aware of what chemicals exist in their space, how to handle them, how to store them, and what to do in case of an emergency.  

Some important general guidelines can be found in the following HSE documents.  

HSE is frequently asked about how to better manage chemical storage. Every lab is unique, with its own storage capabilities and combination of chemicals that can change daily. It’s not possible to give blanket guidance that is applicable to every lab situation, so instead there are general best practices that can be used to review storage in your lab.  

If you have a current inventory of chemicals maintained in the ChemTracker inventory management system, you can also export and sort your inventory to show you recommended storage groups based on the Stanford Compatible Storage Group Guide.  

At a minimum, your lab must:  

  • Maintain an accurate inventory of hazardous chemicals, updated regularly. HSE recommends annual reconciliation through ChemTracker.  
  • Review all chemical containers regularly to ensure that labels are still accurate and legible, containers are still in good condition, there are color or phase changes in the material containers, and they have not expired. 
  • Have appropriate personal protective equipment available for use, and actually used, when working with hazardous chemicals.  
  • Review Safety Data Sheets (SDS) for any new or unfamiliar chemicals. It is best practice to periodically revisit SDS in case any new information is updated.
Secondary Containment

Many labs may need to store several chemical hazard categories in the same area, in which case they must be separated by secondary containment. Secondary containment refers to a system, device, or control measure that stops a leak from leaving a particular area. This may include a physical barrier or container, a filtration system, or an overflow system.  

When talking about secondary containment on an academic research lab scale, this is often a secondary solid-walled tote made of compatible material that is large enough to hold any discharge from the containers inside. For hazardous waste storage, the EPA requires that secondary containment must “must have sufficient capacity to contain 10% of the volume of the containers or the volume of the largest container, whichever is greater.” (40 CFR 264.175) Common material choices include high density polyethylene (HDPE), glass, and metal. Metal secondary containment should never be used for corrosives (particularly perchloric acid, which can react with metal to form explosive perchlorate salts).

General Guidelines

As a starting point, if you do not have a ChemTracker inventory that you can sort by Stanford Storage Groups, you should become familiar with the GHS hazard pictograms ** and re-evaluate your storage practices as below.  

  • Do NOT store chemicals solely by alphabetical order. This practice can result in incompatible materials stored together, which can become a hazard in case of a spill or storage failure. 
  • Corrosives (Corrosion pictogram) must be in corrosives storage cabinets, that are either coated or made with corrosion-resistant materials.
    • Within the corrosives cabinets, separate acids from bases.  
    • If multiple acids and bases are stored, separate inorganic and organic by secondary containment.  
    • Corrosives should be stored below the eye level of the shortest person in the lab. 
    • Secondary containment should be plastic or glass
  • Oxidizers (Flame over Circle pictogram) must be stored in a cool dry place away from other chemicals as well as any wood or paper products. Secondary containment should be plastic or glass.  
  • Water-reactive chemicals must be stored away from moisture, aqueous solutions, and other highly hazardous chemicals. They should ideally be stored in a glove box or in a dessicator, where the dessicant is assessed and refreshed regularly.  
  • Peroxide –forming chemicals form peroxides over time and the results can be shock sensitive and explosive. See the Peroxidizable Organic Chemical Handout for a list of peroxidizable materials.
    •   Always date peroxide forming chemicals upon receipt and upon opening.  
    • Discard any amount of peroxide-forming chemical if it’s been 6 months since opening, if the container is beyond its expiration date, or if there are any physical changes to the contents such as solid precipitation around the lid.  
    • Do NOT move any peroxide-forming chemical that has developed any solid precipitation. Contact [email protected] ATTN Chemical Safety and Hazardous Waste for guidance with pictures.  

** note that older containers predating the 2015 implementation of the GHS likely do not have GHS pictograms and may have older pictograms or lack pictograms entirely. Review any old chemicals to determine if they should be submitted for disposal. If you are keeping the container, look up the SDS and add relevant GHS pictograms to the container if applicable.  

How to view your lab’s ChemTracker report with Stanford Storage Codes 

Note that this is most effective if you have an updated chemical inventory uploaded into your profile. If your inventory is in another format (e.g. Quartzy, LabManager, Avantor, Excel, Word, GoogleSheets), contact [email protected] ATTN Chemical Safety for help having it uploaded into SciShield ChemTracker. 

  1. Login to SciShield.  
  1. At the top of your lab’s profile, click on ChemTracker.
    • If you do not see the ChemTracker tab or reach a page that states that you are not listed as a member in a lab, reach out to your PI, lab manager, or [email protected] ATTN Chemical Safety for help. A 
  1. If you do not see any chemical containers listed, your lab either has not updated their ChemTracker inventory, or you may have filters already pre-populated in your search. Clear any filters if they are populated.  
  1. If you see a list of chemical containers, use the Download button at the upper left to download a CSV file.  
  1. Open the CSV file and navigate to column “AC.” The letters displayed correspond to Stanford Storage Codes 

Using the Stanford Storage Codes 

  • G- may be kept in general lab storage. These may be kept generally with the other storage codes, but is an inefficient use of hazardous materials storage space.  
  • A, C, D, and F – should be kept in a corrosives storage cabinet, separated from each other letter code using secondary containment. 
  • I- should be in a corrosives cabinet, separated from the other corrosives codes above 
  • E- should be stored separately from other storage groups 
  • L- should be stored in flammables cabinets 
  • B- should be stored in an appropriate dessicator, glove box, or other dedicated cabinet away from other storage codes, especially L.  
  • X and K- must be stored completely separate from every other letter code, including its own.