Control Procedures for Pyrophoric Materials
Pyrophoric materials ignite spontaneously when exposed to air. Moreover, they are commonly associated with flammable solvents such as pentane, hexane, heptane and diethyl ether. This combination poses a significant hazard to users. Other hazards posed by these materials include corrosivity, water reactivity, peroxide formation and toxicity.
A number of common reagents are pyrophoric, including (but not limited to):
- Organolithium reagents - Typically in hydrocarbon solvents. Note: Tert-butyllithium solutions are highly pyrophoric.
- Organomagnesium reagents including Grignard Reagents (RMgX) - Typically in hydrocarbon solvents. Neat reagents are pyrophoric.
- Organoaluminum reagents - Neat or in hydrocarbon solvents. Neat reagents are highly pyrophoric.
- Organozinc reagents - Neat reagents are pyrophoric.
- Boranes - Neat reagents are pyrophoric.
- Other pyrophoric liquids include metal alkyls such as trimethylaluminium, trimethylgalium and trimethylindium.
It is imperative that personnel understand the hazards associated with pyrophoric materials and their solvents, and understand how to control these hazards.
Substitution and Chemical Inventory Management
Prior to purchasing a pyrophoric material, users shall:
- Review the hazards of the material and assess the conditions under which it will be used. Hazard information may beobtained from the MSDS or other information sources such as Bretherick’s Handbook of Chemical Reactive Hazards. or by consulting with EH&S Industrial Hygienists.
- Identify and use safer chemical alternatives if possible.
- Limit the amount purchased. As an alternative, consider borrowing what you need from a colleague in your group or contact the Chemical Management System Coordinator to assist you in finding a source of the chemical at LBNL.
- Enter pyrophoric materials into the Chemical Management System (CMS).
- Keep working quantities to a minimum. Store and use the minimum for the operation. Then dispose of the excess.
- Do not stockpile pyrophoric chemicals.
- Conduct periodic cleanouts to prevent accumulating unneeded pyrophoric chemicals.
Activity Hazard Documents
Activity Hazard Documents (AHDs) are required for work involving pyrophoric material. An AHD is a formal work authorization that lists controls and procedures to reduce the risks associated with a higher-hazard activity to an acceptable level. A single AHD may be written for multiple operations or activities conducted in one or more areas, provided they are done under the same PI.
Training and qualifications
EHS 348 – Chemical Hygiene and Safety Training, and EHS 530 – Fire Extinguisher Safety are required. However, because technique and handling practices are critical, on the job training (OJT) given by a knowledgeable, experienced worker, such as the Work Lead or AHD Principal Investigator shall be the primary training method. OJT shall be documented in the AHD. The objectives of OJT are to ensure that users:
- Understand the hazards of pyrophorics
- Understand the controls for pyrophorics
- Know, understand and use
- Safe storage practices
- Labeling procedures. Consult the section entitled: Labels, for labeling requirements for primary and secondary containers.
- Safe handling practices, including transferring and use of equipment and apparatuses such as syringes and Schlenk lines
- Engineering controls
- Selection and use of PPE and
- Emergency procedures.
Users may work with pyrophoric materials unsupervised provided that all of the following conditions are met:
- OJT is completed and documented.
- The Work Lead has observed the user performing an unassisted procedure.
- The user has demonstrated proficiency in the safe handling and use of pyrophorics to the satisfaction of the Work Lead.
- Both the user and the Work Lead are confident that the user can perform the work safely.
Safe Storage Methods
Consult the section entitled Storage Guidelines for hazardous material storage requirements, recommendations and information on chemical incompatibility. Additional requirements are provided below.
- Store pyrophorics in an inert glove box. Pyrophoric materials and flammable liquids may be stored in the same inert glovebox.
- If storing in an inert glovebox is not possible, then keep pyrophorics in an airtight container and store in a flammable storage locker specifically designated for pyrophorics. Pyrophoric materials and flammable liquids may not be stored together in the same flammable storage locker.
- Keep pyrophorics in their original containers (e.g. sure seal bottles) unless experimental work requires transfer to other containers such as Straus flasks. Note: Sure seal bottles may leak when the septum is perforated. Therefore, inspect them on a regular basis and replace caps in an inert glovebox if necessary.
- Pyrophoric materials may be stored in refrigerators that are designed and constructed for storing flammable liquids. However, the refrigerator(s) must be specifically designated for pyrophorics. Pyrophoric materials and flammable liquids may not be stored together in the same refrigerator. Consult the Storage Guidelines section for additional requirements for refrigerators.
- Use secondary containment for all liquids.
Handling, Transfer and Use of Pyrophorics
All equipment in a pyrophoric reaction must be used following air-sensitive techniques such as:
- Oven dry glassware used for pyrophorics.
- Flush glassware, syringes, and conveyance lines with argon or nitrogen.
- Use syringes equipped with Luer-locks to secure needles.
- The maximum volume that can be transferred with a syringe is 20 ml.
- Use cannulas for transferring larger volumes of pyrophorics.
- Clamp the reagent bottle and the receiving vessel to prevent tipping and to allow the free use of both hands.
- Conduct operations inside an inert glovebox when possible.
- When it is not practical to use a glove box conduct operations in a fume hood.
- Keep the sash of the hood to the lowest practical height.
- Gloveboxes and fume hoods must have a current approval sticker.
- Keep flammable and combustible loading to a minimum in fume hoods and glove boxes. This includes reagents, paper and cloth.
- More detailed descriptions may be found in “The Manipulation of Air-Sensitive Compounds” by Shriver and Drezdzon, John Wiley & Sons, New York, 1986, and in Aldrich Technical Bulletin AL-134, “Handling of Air-Sensitive Reagents,” which is included with the purchase of air-sensitive chemicals and may be obtained from the Aldrich Technical Bulletins website.
PPE & Use of Nomex (fire retardant) lab coats
- The minimum PPE for handling pyrophorics outside of inert gloveboxes is: Nomex lab coat , safety glasses with side shields, long pants, closed toed shoes and chemically resistant gloves. Disposable lab coats and lab coats made of polyester blends are prohibited for use with pyrophoric materials. If Nomex lab coats are not practical, then a fire retardant cotton lab coat may be used provided that a laundry is employed that is approved for laundering such garments in accordance with the manufacturer's requirements. Lab coats may be ordered and laundered through a service such as Mission Linen Supply.
- Cover goggles and/or face shields shall be used as warranted by the hazard. Note: Face shields must be worn in conjunction with approved safety glasses or cover goggles. Consult the Eye and Face Protection section or an EH&S Industrial Hygienist for further guidance
- Glove selection will normally be based on the solvent containing the pyrophoric material. Consult the Glove Selection section or an EH&S Industrial Hygienist for further guidance.
Emergency procedures, including extinguishing media for fires
- Consult the “Emergency Procedures and Equipment” section for emergency actions regarding chemical spills and personal exposure to chemicals.
- In addition to these requirements, the following applies to spills and fires involving pyrophoric compounds:
- Safety must be the primary concern regarding spills. Do not attempt to clean up pyrophoric material spills that occur in an ambient atmosphere. Warn others, leave the area and call the emergency number on the nearest safe lab phone (7-911 at LBNL).
- You may clean up spills in inert glove boxes only if it can be done safely.
- Avoid using combustible or reactive materials (such as paper towels) to clean up spills.
- Keep material on hand to absorb spills Inorganic diatomaceous earth (Celite), clay based kitty litter, and/or molecular sieves (13X) may be used. Ensure these materials are dry.
- Appropriate Class D fire extinguishers shall be staged outside the work area. There are several different types of extinguishing media. Contact the Lab’s Fire Marshal for proper selection.
- If researchers choose to stage Class D fire extinguishers in the lab area then they will be responsible for performing the monthly inspections and for coordinating fire extinguisher service with Lab’s contractor. Contact the Lab’s Fire Marshal for guidance on selecting, staging and inspecting fire extinguishers and for coordinating fire extinguisher services.
- If you use a fire extinguisher, ensure you empty the entire contents. As an option, plastic baggies of fire extinguishing agent, such as Met-L-X or Lith-X, may be kept in inert glove boxes where the agent is appropriate for the material being handled. These baggies are not a substitute for the appropriate fire extinguisher but rather, serve as a handy material to help extinguish a small fire. Employees must have OJT in the proper use of these extinguishing materials.
- Quench or otherwise neutralize spill clean up materials prior to removing from the inert glove box.
- Only trained personnel may attempt to control small, contained fires or spills. If fumes escape into the breathing zone, do not attempt to put out the fire. Large or unconfined fires or spills, or fires where the ventilation system (glove box or fume hood) does not contain all of the fumes, must be handled by fire fighters. When in doubt, activate the nearest fire alarm and call the emergency number on the nearest safe lab phone (7-911 at LBNL).
- Information on waste disposal may be found in the Lab’s Waste Generator Guidelines (Pub 3092). Only those who have completed Hazardous Waste Generator Training (EHS0604) are permitted to add waste to an SAA. Consult with the EH&S Waste Generator Assistant who provides service to you Division for guidance on the proper disposal of pyrophoric materials.