Chemical Storage

The safe storage of hazardous chemicals is an essential part of laboratory safety.

Chemical storage is complex—there is no one-size-fits-all plan to store chemicals—
but there are regulations, campus requirements, and best practices that can guide
the process. The general concept is to prevent chemicals from causing harm to
people, property, other chemicals, or the environment.

In order to fully understand the hazards associated with stored chemicals you first
need to know what chemicals are being stored. Safe storage begins with an up-to-
date inventory of chemicals and knowledge of the hazards posed by each chemical

General Storage Requirements

• All chemicals must be stored in a safe, secure location.
• Shelves should be level, stable, and secured to the wall or another stable
• Store chemicals away from direct sunlight, sources of heat, and egress
pathways
• Hazardous chemicals must be stored below eye level.
• Do not store chemicals on the floor, window ledges, or balconies.
• Keep containers closed unless you are dispensing a chemical or adding to the
container.
• Provide secondary containment for liquids whenever possible. Dishpans or
polyethylene trays work
• Don’t store chemicals in a sink or fume hood, except for certain toxic gases
that are so dangerous they can only be stored in a gas cabinet or fume
• Label containers, and be sure container is compatible with the chemical
• Use rated storage cabinets or safety cans whenever possible—required for
>10 gal. of flammables.
• Cold rooms, refrigerators, and freezers have additional requirements,
particularly for flammables.

Chemical Segregation
Chemicals should always be segregated according to their specific hazard(s) to
prevent unintended reactions. Begin by categorizing and separating chemicals by
the following categories. Note that the order is intentional, as discussed below.

• Pyrophorics
• Water reactives
• Flammables
• Corrosives
• Oxidizers
• Toxics

Other types of materials require more specific storage requirements such as

• Explosives
 • Compressed gases
• Cryogens

As a general rule, chemicals need to be physically segregated from incompatible

chemicals; some key requirements are listed below.

• Store flammable liquids in approved safety containers in . Do not store

anything but flammable or combustible liquids in these
• Segregate acids from
• Keep oxidizers away from flammables and combustibles.
• Keep corrosives away from substances that they may react with and release
corrosive, toxic, or flammable vapors
• Do not store chemicals alphabetically unless they are compatible.

Multiple Hazard Classes

Many chemicals belong to more than one chemical family or hazard class. In many
cases, chemicals need to be evaluated on a case-by-case basis. Ideally, guidelines
for each category should be observed, but this may not be possible in all instances.

One strategy is to prioritize the hazards of a specific chemical. The hazards listed
above are prioritized for this purpose, from most severe to least. A pyrophoric
chemical, for example, may also be a flammable liquid, but the pyrophoric property
should outweigh the flammability for storage purposes.

Glacial acetic acid is a common example, as it is both a corrosive acid and a

combustible liquid. It should be stored away from corrosive bases, such as sodium
hydroxide, and also from oxidizing acids, such as nitric acid. Storing acetic acid in a
flammable storage cabinet would be appropriate, prioritizing the combustibility over
the corrosivity. If flammable storage space is at a premium, storage in a corrosives
cabinet would also be acceptable; however, it would need to be further segregated
from the other incompatible corrosives by utilizing multiple cabinets or secondary
containment.

Storage Limitations
It is best practice to minimize the quantities of hazardous chemicals on hand
whenever possible. Minimization of stored chemicals is a key way to reduce the
likelihood and severity of an incident involving said chemicals. Chemical storage
limits, from various regulatory bodies and campus policy, are outlined in Appendix D
of the campus Chemical Hygiene Plan. It is important to note that storage
limitations, particularly based on fire code, often extend to large groupings of labs or
even entire floors of buildings. Each space is different, so contact Chemical Safety
staff for an evaluation.

Where to find information

The first source for chemical-specific information should be the labels and safety
data sheets (SDSs) from the manufacturer. You may also contact Chemical
Safety for advice. A poster is also available, providing chemical storage basics. One
can be requested via our website.

Storage Cabinets and Safety Cans

Flammable storage cabinets

Flammable storage cabinets are designed to meet specific requirements outlined by
various standards such as OSHA, NFPA, IFC, and UL. They are specifically
constructed to contain flammable materials and slow the spread of a fire towards the
materials in the cabinet.

When purchasing a cabinet for your lab, look for a cabinet which is OSHA and NFPA
approved (which will fulfill UL 1275) and has self-closing doors to comply with IFC. If
you have an existing cabinet, it should be labeled if it meets any of these standards.
Contact chemical safety if you need further information on your available storage
cabinets.

Flammable storage cabinets are not required to be vented, and it is not

recommended to do so in most cases. Improper venting can negate the fire
protection provided by a cabinet.

Safety Cans
A safety can is a rated container of not more than 5 gallons (20 liters) capacity
having a screen or strainer in each fill-and-pour opening and having a spring-closing
lid and spout cover designed to safely relieve internal pressure when exposed to fire.
They should be UL or FM approved as well as OSHA approved. They make appear
similar, but typical home gasoline storage cans are not the same and should not be
used in laboratories.

Corrosive Storage Cabinets

Corrosive storage cabinets do not have specific regulatory requirements. They
should be designed by the manufacturer to resist corrosion. Polyethylene cabinets
are generally the most resistant, while steel cabinets will have a corrosion-resistant
coating and oftentimes contain polyethylene liners. As an added benefit, some steel
cabinets also meet the requirements of flammable storage cabinets, which may be
necessary if you are storing flammable corrosives such as pyridine, triethylamine, or
glacial acetic acid—always confirm this rating with the manufacturer. Wooden
cabinets will generally resist corrosion (except for the metal hardware), but they
should never be used for storing any oxidizing acids, such as nitric or perchloric acid.

Venting of corrosive cabinets may be beneficial if storing volatile corrosives such as

hydrochloric acid, but it is not a requirement. Many cabinets below fume hoods have
ventilation connections for this purpose. If you have questions about your existing
cabinets, or if you would like additional information about corrosives storage,
contact chemical safety.

Hazard Communication
The Hazard Communication Standard (HCS) was written and enacted in 1983 by the
Occupational Safety and Health Administration (OSHA) and is enforced in the State
of Wisconsin by the Wisconsin Department of Safety and Professional Services (WI
Statues 101.055). It is based on a simple concept that employees have both a need
and a right to know the hazards and identities of the chemicals that they are exposed
to when working in non-laboratory work areas.

In March 2012, the Hazard Communication Standard was revised to align with the
United Nations’ Globally Harmonized System of Classification and Labeling of
Chemicals also known as GHS. The revised standard requires the manufacturer or
importer of chemicals to classify their chemicals according to their physical and
health hazards, establish specific formatted shipping labels with the chemical
identity, pictograms, signal works, precautionary statements, hazard statements and
the manufacturer name, address and phone number as well as create a 16 section
Safety Data Sheet (SDS) formerly Material Safety Data Sheet (MSDS) for each
chemical.

There are six elements of the HCS and GHS: hazard determination and
classification, chemical inventory, labeling, Safety Data Sheets (SDS), employee
training & written program.

Chemical Inventory

Chemical inventories are a vital part of a chemical safety program. Inventories

provide a record of room and building content which is important in emergency
situations as well as inventory control.

Each campus department working with or using hazardous chemicals must complete
and maintain a chemical inventory. At a minimum, the inventory should include the
chemical name as it appears on the shipping label and SDS, the manufacturer’s
name and address and the location of the chemical (building & room). It must be
updated annually or as needed and kept with the written plan.

Labeling

All containers of hazardous chemicals must be labeled by the manufacturer or

importer according the recently revised Hazard Communication Standard and
Globally Harmonized System of Classification and Labeling of Chemicals (GHS).
The label created and used by the manufacturer is called the shipping label.
Chemicals that are transferred to secondary containers must also be labeled with a
workplace label.
 • Shipped containers which are the original container must be labeled
with the GHS label which includes the identity of the chemical, signal work,
pictogram, hazard statements, precautionary statements and the name,
address and phone number of the manufacturer.

Example of a GHS Shipping Label

• Secondary containers (transferred chemicals) can be labeled

with either the GHS label or a label which contains the identity of the chemical
and words, pictures, symbols or a combination which provides information
regarding the physical and health hazards of the chemical. This is called the
workplace label.
• Container for use by one person. A portable container which is filled
from a labeled container that is for the employee’s immediate use during that
work shift, will be used by the same employee, will not be left unattended by
that employee and will be used entirely, need not be labeled.
• Stationary process containers. Instead of a label, a posting, placard
or sign may be used on stationary process containers, pipes or piping
systems. The identity of the hazardous chemical and appropriate hazard
warning must be included.
• Never deface or remove any container labels.
• Labels and other forms of warning must be legible,
prominently displayed and in English. Employers having
employees who speak other languages may add the information in their
language as long as the information is presented in English as well.

Employee Information

Each employee shall be provided with information n the hazardous chemicals they
work with upon their initial assignment and whenever a new chemical is introduced.
The information must include any operations in their area where hazardous
chemicals are present, the location of the written program and location of the
chemical inventory and Safety Data Sheets.
Written Hazard Communication Program

The written Hazard Communication Program describes how the facility will develop,
implement and maintain at each workplace, the elements of the standard. It is
intended to be a blueprint for implementing the program and provides assurance that
all aspects of the requirements have been addressed. The written program must
include a list the chemicals present in the workplace. Who within the organization (by
job title) is responsible for the various aspects of the program such as labeling,
Safety Data Sheets (SDS), non-routine tasks, outside contractors and employee
information and training.

The written program includes information on how the employees have access to the
SDS, precautionary measures to be taken when working with chemicals, the labeling
system used in the workplace, employee information and training, non-routine tasks,
contractor employees and multi-employer worksites. The written program is available
to employees and evaluated annually.

Outside Contractors

The purpose of the Hazard Communication Standard is to ensure that the hazards of
chemicals are identified by the manufacturer and then transmitted to employers and
employees. This is true also for contractors working with hazardous chemicals.

Contractors who perform work on campus need to have a Hazard Communication

Program in place. The contractor must inform the campus of any hazardous
chemicals they intend to bring in or use while on university property and
precautionary measures that need to be taken to protect employees and the labeling
system. Likewise, when contractors are working on the campus, they must be
informed of any hazardous chemicals that the campus uses that they may come in
contact with or be exposed to in the project area. Both parties must have Safety Data
Sheets (SDS) for each hazardous chemical accessible for the duration of the project
and provide information on their labeling systems and any precautionary measures
that need to be taken to protect employees.

Non-Routine Tasks

When employees are required to perform hazardous non routine tasks involving
chemicals (tasks that are completed infrequently), training must be conducted to
inform the employees of the physical, health, asphyxiation, combustible dust and
pyrophoric gas hazards of the chemicals, precautions needed, Personal Protective
Equipment (PPE) required, first aid, emergency and spill procedures and methods to
detect the release or presence of chemicals.