Environmental Health and Safety Update
Chemical Storage System
Overview
The proper segregation and storage of chemical reagents is an important safety measure because the
accidental mixing (i.e., leaking or broken containers) of incompatible chemicals may cause fires,
explosions, or the production of toxic gases. However, knowing what chemicals are incompatible can be
difficult and the proper organization can be time-consuming. Safe storage of chemicals begins with
well-labeled containers and the separation of incompatible chemicals.
To facilitate this process, Environmental Health and Safety (EHS) has implemented the Chemical
Storage System. This system, which is integrated in the ChemTracker Chemical Inventory Database,
defines 11 compatibility groups that enables users to safely organize and segregate chemicals with
different or multiple hazards. A major advantage of using ChemTracker is that once a chemical is added
to the inventory, ChemTracker will automatically identify the proper storage group for that chemical.
ChemTracker can also be used to generate a Chemical Storage Group report for all chemicals in an
inventory making segregation a simpler and more efficient process.
Applicability
This Update is applicable to all areas (laboratories, clinics, service areas, mechanical rooms, or print shops)
that store and/or use chemicals. The Chemical Storage System helps ensure that incompatible chemicals
will not have the chance to react while they are being stored. This chemical storage system applies to all
chemical storage. Working solutions that are less than 1 liter, non-toxic, and non-reactive are exempt
from this requirement.
Responsibilities
Environmental Health and Safety (EHS) provides in-field assistance and training on segregating
chemicals wherever chemicals are used or stored upon request.
Principal Investigators, Directors, Managers, and other chemical owners ensure all chemicals are
segregated and stored in compatible groups.
Chemical Users comply with the chemical storage practices of the work area and ensure that all
chemical containers are returned to their proper location after use.
Procedures for Chemical Segregation
Follow the steps below to segregate chemicals based on their storage groups:
1. Compatible Storage Groups:
 The storage group determination of any material can be determined by referring to the
chemical safety information available through ChemTracker or by referring to the “Hazards
March 2013
Weill Cornell Medical College ▪ Environmental Health and Safety
402 East 67th Street, Room LA-0020 ▪ Phone 646-962-7233 ▪ FAX 646-962-0288
ehs@med.cornell.edu ▪ http://weill.cornell.edu/ehs
EHS Update – Chemical Storage System
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Identification” and “Toxicological Information” sections of the Safety Data Sheet (SDS;
formerly Material Safety Data Sheet, or MSDS).
Storage groups are groups of chemicals that if stored together will not react violently if
mixed. A storage group code (A-X) is automatically assigned to each chemical included in
the ChemTracker Chemical Inventory System Database.
Storage Group Codes are used for storing solids, liquids and gases.
Chemicals with multiple hazards are stored according to the primary hazard.
See Table 1 for the storage group codes, descriptions, and examples.
Table 1
Code
A
B
C
D
E
F
G
J
K
L
X
Storage Groups
Compatible Organic Bases
Compatible Pyrophoric and Water Reactive
Materials
Compatible Inorganic Bases
Compatible Organic Acids
Compatible Oxidizers including Peroxides
Compatible Inorganic Acids not including
Oxidizers or Combustibles
Not Intrinsically Reactive or Flammable or
Combustible
Poison Compressed Gases
Compatible Explosive or other highly
unstable materials
Non-Reactive Flammables and
Combustibles, including solvents
Incompatible with All Other Storage Groups
Examples
BIS TRIS, Diethylamine, Imidazole,
Triethanolamine
Tert-Butyllithium, Sodium Borohydride,
Sodium Hydroxide, Ammonium Hydroxide
Acetic Acid , Maleic Acid
Nitric Acid, Periodic Acid, Perchloric Acid,
Potassium Permanganate
Phosphoric Acid, Hydrochloric Acid, Sulfuric
Acid
Acrylamide, Sodium Bisulfate, Coomassie
Blue, Sodium Chloride
Ethylene Oxide, Hexafluoropropylene, Sulfur
Dioxide, Trifluoromethyl Iodide
Picric Acid Dry, Tetrazole, Ammonium
Permanganate
1-Butanol , 1-Propanol, Acetic Anhydride ,
Acrolein, Formamide, Sigmacote,
Sodium Azide , Picric Acid Moist, Arsine
2. Storage Group Update Report from ChemTracker Version 1:
The Storage Group Update Report feature in the ChemTracker database allows the users to identify
the different chemical storage groups for materials within their chemical inventory. Below are the
steps to generate the Storage Group Update Report in ChemTracker Version 1:
A. Login:
 Go to the ChemTracker main page (www.weill.cornell.edu/ehs/chemtracker) and click
on the link under reporting.
 Login to ChemTracker Version 1 using your ChemTracker username and password . Make
sure your browser is set to allow pop-up windows from the ChemTracker site.
B. Select Inventory:
 Under the Inventory tab, the ChemTracker Search Screen will open. Use the search
criteria and run a query features to open the inventory you would like to generate a report
for.
C. Generate Report:
 Once the inventory appears, select the “INVENTORY REPORTS” option.
 Select the “Storage Group Update Report” and click “View Report” when the next
window opens.
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EHS Update – Chemical Storage System
3. Chemical Storage and Segregation:
Storage groups must be stored separately from each other. However, if space does not allow this,
multiple groups can be stored on the same shelf or within the same storage cabinet if each group
is segregated by secondary containment as outlined in the WCMC Compatible Storage Group
Classification System diagram and general and storage group-specific requirements.
4. General Storage Requirements:
 All chemicals must be clearly labeled.
 Label the storage location with the assigned Storage Group.
 Chemicals should not be stored above eye level.
 No storage of chemicals, excluding standard detergents, under sinks.
 Every chemical should have an identifiable storage place and should be returned to that
location after each use.
 Chemical storage in hoods should be minimized to avoid blocking rear baffles and interfering
with airflow into the hood.
 Large containers should be stored on lower levels. Liquid chemicals and toxic powders must
not be stored on the floor.
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EHS Update – Chemical Storage System
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Larger chemical bottles should be stored towards the back and smaller bottles should be
stored up front where they are visible. Chemical bottles should be turned with the labels
facing out so they can be easily read.
Chemical storage on bench tops should be minimized in order to reduce the amounts of
chemicals unprotected from a potential fire and to prevent them from being easily knocked
over.
The FDNY sets chemical storage limits on the amount of flammable liquids, flammable
gases, flammable solids, oxidizing materials, and reactive/unstable chemicals that may be
stored in a laboratory. The storage limits are based on the fire rating of the lab and the
presence of a sprinkler system.
Lab
Type
Fire
Rating
Fire
Protection
Flammable
Liquids
Flammable
Solids
Oxidizing
Materials
Unstable
and
Reactive
I
2 hour
Sprinklers
30 gallons
15 lbs
50 lbs
12 lbs
II
1 hour
Sprinklers
25 gallons
10 lbs
40 lbs
6 lbs
III
2 hour
No
sprinklers
20 gallons
6 lbs
30 lbs
3 lbs
IV
1 hour
No
sprinklers
15 gallons
3 lbs
20 lbs
2 lbs
Flammable Gas Storage Limits
Area of Laboratory
in square feet
Up to 500 sq. ft.
Per additional
100 sq. ft.
Maximum per Laboratory
Unit
Maximum Capacity
in cubic feet (water
container capacity)
9.24
1.54
15.4
5. Storage Group-Specific Requirements:
 Flammable Storage (Group L)
o The capacity of glass containers shall not exceed one (1) gallon. Metal containers are
required for storage of flammable liquids exceeding one gallon.
o Store flammables (Group L) in vented flammable cabinets whenever possible (e.g. under
hoods).
o Explosion-proof or flammable-proof refrigerators must be utilized when flammable
liquids must be refrigerated. The use of standard refrigerators to store flammable liquids
is prohibited.
o Keep flammables away from all ignition sources such as open flames, hot surfaces, direct
sunlight and spark.
o Flammable gases are prohibited from use or storage below grade.
o Peroxide-forming chemicals are typically classified as Flammables (Group L). In
addition to the flammable specific storage requirements, peroxide-forming chemicals
must meet the following requirements:
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EHS Update – Chemical Storage System
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Write the date received, opened and expired on all containers.
Store in airtight containers in a dark, cool, and dry place.
Do not store in direct sunlight as light can accelerate the chemical reactions that form
peroxides.
Never store peroxide formers in a freezer because a change from a solid to a liquid
can cause detonation.
Discard peroxide forming chemicals before the expiration date printed on the
container label.
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Water-Reactive and Pyrophoric Chemicals (Group B)
o Water reactive chemicals must be stored in a closed water-tight container and in a manner
to prevent direct contact from water and fire sprinkler systems (i.e., not under sinks or on
open shelving). They should be segregated from any corrosives and aqueous liquids.
o The storage area for water-reactive chemicals must be labeled “Water-Reactive
Chemicals.”
o Prevent pyrophoric chemicals from contacting air by taking extreme care to prevent
containers from leaking or breaking. For additional protection, consider keeping the
chemicals in the manufacturer’s original shipping package (i.e., surrounded by
vermiculite inside a metal can).
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Corrosive (Group A,C,D,F)
o Store corrosive chemicals (Group A, C, D and F) in dedicated corrosion resistant and
ventilated cabinets whenever possible.
o Secondary containment must be used when storing acids on bare metal.
o Organic acids (Group D), such as Acetic acid, Lactic acid, and Formic acid (Group D),
are considered combustible and corrosive and can be stored in flammable storage
cabinets.
o Do not store acids near any cyanide or sulfide containing chemicals in order to prevent
the generation of highly toxic hydrogen cyanide or hydrogen sulfide gases.
o Do not store concentrated acids next to household bleach, as mixing will generate highly
toxic chlorine gas.
o Do not store concentrated acids next to window cleaner or ammonium hydroxide, as
mixing will generate highly toxic chlorinated amine gases.
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Highly Toxic Chemicals (Group X)
o Segregate highly toxic chemicals (Group X) from other hazard groups.
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Containers should be tightly sealed to minimize exposure to personnel and contamination of other
chemicals.
o
Maintain the lowest possible inventories of highly toxic chemicals.
Oxidizers (Group E)
o Do not store oxidizing acids (Group E: such as perchloric acid, nitric acid) on wooden
shelves or in cardboard boxes.
o Segregate oxidizing acids (Group E) (nitric, perchloric, chromic acid, chromerge) from
organic acids (acetic, formic, etc.) to prevent fires.
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EHS Update – Chemical Storage System
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Compressed Gas (Group E, G, L)
o Limit the quantity of compressed gas cylinders on site to what will be used within a
reasonable period of time.
o Store cylinders upright and secure them with a chain, strap, or cable to a stationary
building support (i.e., chain and hook) or to a cylinder cart to prevent cylinders from
tipping or falling.
o Store cylinders in a dry, well-ventilated area away from flames, sparks, or any source of
heat or ignition.
o Place cylinders in a location where they will not be subject to mechanical or physical
damage, heat, or electrical circuits to prevent possible explosion or fire.
o Cylinders should not be exposed to continuous dampness or stored near salt or other
corrosive chemicals or fumes. Corrosion may damage cylinders and cause their valve
protection caps to stick.
o Mark the cylinder storage areas with proper precautionary signs, such as “Storage of
flammable, oxidizing, or toxic materials.”
o Caps used for valve protection should be kept on the cylinders at all times, except when
the cylinder is actually being used or charged. Cylinder valves should remain closed.
o Segregate empty cylinders from full cylinders.
o When empty cylinders are to be returned to the vendor, mark them “Empty”.
6. Training and Assistance:
EHS is available to provide on-site assistance to all chemical users including ChemTracker user
training and segregation/storage assistance. Contact EHS for any questions at 646-962-7233 or
chemtracker@med.cornell.edu.
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