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Mixing incompatible materials together can result in explosions, fires and severe injuries. An article in Lab Manager Magazine reports that improper storage of chemicals accounts for 25 percent of all chemical accidents in labs. The article describes the following examples of two serious lab incidents, both involving nitric acid:
- Nitric acid mixed with an organic solvent exploded in a university lab.
- Someone put nitric acid into a container previously used for methanol. Over the next 12 to 16 hours, the nitric acid reacted with the residual methanol. This created carbon dioxide and caused pressure to build up. Eventually, the container exploded.
Mixing incompatible chemicals can cause serious injuries and damage to property. Learn how safe hazardous chemical storage helps avoid such consequences.
Chemical Storage Guidelines: Understand the Chemical SDS
A Safety Data Sheet (SDS) comes with every chemical. All SDS follow a standard format governed by OSHA through their Hazard Communication Standard (HCS). Each SDS has 16 sections, detailed below. [Note: Sections 12 – 15 must be included on a SDS to be consistent with the United Nations’ Globally Harmonized System of Classification and Labeling of Chemicals (GHS). But, OSHA only mandates the headers. All content in these sections fall under other agencies’ jurisdictions.]
|1||Identification||Product or chemical name, including contact details for manufacturer||Mandatory|
|2||Hazard(s) Identification||Classes of hazards and appropriate warnings – includes labelling pictograms||Mandatory|
|3||Composition||Ingredients of compounds and mixtures and chemical identity||Mandatory|
|4||First-Aid Measures||Initial first-aid care instructions after exposure||Mandatory|
|5||Fire-Fighting Measures||Methods to extinguish a fire||Mandatory|
|6||Accidental Release Measures||Response measures for spills, leaks and releases||Mandatory|
|7||Handling and Storage||Guidance for handling and storage, including container compatibility issues||Mandatory|
|8||Exposure Controls / PPE||Measures to limit exposure and appropriate PPE for the specific chemical product||Mandatory|
|9||Physical and Chemical Properties||List of relevant properties, including appearance, odor, flammability, etc.||Mandatory|
|10||Stability and Reactivity||Descriptions of reactivity, chemical stability and indications of possible hazardous reactions||Mandatory|
|11||Toxicological Information||Description of toxicological and health effects of exposure||Mandatory|
|12||Ecological Information||Description of impact on environment in the case of release||Non-mandatory|
|13||Disposal Considerations||Advises on methods of disposal, recycling and reclamation of chemicals and containers||Non-mandatory|
|14||Transport Information||Classification information for transporting by road, air, rail or sea||Non-mandatory|
|15||Regulatory Information||Description of any relevant regulations specific to the product||Non-mandatory|
|16||Other Information||Revision history of SDS and other useful information||Mandatory|
Chemical Storage Guidelines: Learn the Compatibility Issues Across Chemical Groups
It may seem obvious to store chemicals in alphabetic order for ease of use. But, this could result in storing incompatible chemicals right next to each other. Copper (II) sulfide reacts explosively with cadmium chlorate. A vigorous reaction occurs when hydrogen peroxide and iron (II) sulfide mix.
Chemical groups also react with other groups. Oxidizers are not directly flammable. But, they release oxygen, a key component of the fire triangle. It is risky storing them alongside flammable materials. Safety experts suggest a systematic approach to categorizing and storing chemicals.
Unfortunately, OSHA and the HCS requirements fail to provide one single method for chemical segregation and grouping. Many organizations have developed their own methods. Some of these are very complex. For instance, the U.S. Coast Guard uses 43 separate chemical groups to segregate chemicals for storage. But, simpler classifications exist that are comprehensive enough for most applications. Sciencelab, a leading chemical and laboratory equipment company, suggests these seven chemical groups:
- Highly reactives
- Extreme toxics / regulated materials
- Low hazard
The University of Iowa uses a similar breakdown with nine chemical groups:
- Flammable liquids
- Volatile poisons
- Oxidizing acids
- Organic and mineral acids
- Liquid bases
- Liquid oxidizers
- Non-volatile poisons
No matter what organizational method is used for segregation, it is important to understand how these chemical groups react with one another and the associated risks.
Chemical Storage Guidelines: Tips for Safe Storage in a Safety Cabinet
- Don’t store chemicals in alphabetic order.
- Use shelf dividers and clear labeling for organization. Simple housekeeping and order goes a long way toward preventing human error, such as placing the wrong chemical in the wrong place.
- Only store hazardous chemicals in an approved flammable safety cabinet. Look for FM and UL approvals. These certify the cabinet meets OSHA and NFPA standards.
- Never store cardboard boxes in a flammable safety cabinet. Cardboard and paper may get saturated with flammable materials from spills and leaks. This creates a major fire risk.
- Always store flammable materials in a flammable storage cabinet, even if the chemical has other hazards. For example, aldehydes are both flammable and toxic. But, flammability trumps toxicity. Store aldehydes in a flammable storage cabinet. Secure it to prevent unauthorized access.
- Use clear signage on safety storage cabinets to identify its contents. Justrite safety cabinets feature exclusive Haz-Alert™ warning labels that inform all workers and first responders of its main chemical hazard – FLAMMABLE, ACID or HAZARDOUS. Justrite safety cabinets also come with a pack of 10 standard labels to identify specific contents.
- Never keep bottles of chemicals in a fume hood. Vapors from unsealed bottles could react with other chemicals in the fume hood, causing an explosion. Use Justrite under fume hood safety cabinets instead – both flammable and corrosive options available.
- Store non-flammable corrosive chemicals in polyethylene cabinets, such as a Justrite Polyethylene Corrosive and Acid Cabinet. These have no metal parts, since even corrosive fumes cause rust and reduce the life of your cabinet. Wooden laminate cabinets with a laminate finish are also suitable when storing corrosives.
Contact Justrite for Safe Hazardous Chemical Storage Solutions
Justrite specializes in flammable and hazardous chemical storage solutions. We offer a wide range of products for laboratory environments, including cabinets for corrosives and hazardous materials as well as safety containers for dispensing and HPLC disposal. All products meet and exceed codes and regulations. Browse all our safety cabinets or contact us to discuss your chemical segregation and storage needs.
- Grainger. Chemical Storage Compatibility Guidelines
- Sciencelab. Chemical Categorical Storage
- University of Iowa. Chemical Storage: Nine Compatible Storage Group System
- Justrite. FAQ