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Training Programs & Policies Documents
Highly reactive materials are those agents that undergo rapid chemical change causing exothermic or other self-accelerating reactions when subjected to heat, impact, friction, light, catalysts, or other initiation. These agents are materials that will detonate or deflagrate.
Highly reactive materials encompass (but are not limited to):
Many of the above classes of materials overlap with other hazard types (e.g., organometallics may be pyrophoric). The list is intended merely to provide guidance for determining whether this section applies to the research in your lab. Exact classification is not necessary.
NOTE: A process may involve more than one type of hazard for example, compounds may be reactive, may cause system over pressurization, and may be used with vacuums (e.g. highly reactive materials, high-pressure systems, vacuum systems). Be sure to address all the hazards that apply to your process.
The categories listed below are not exhaustive and do not necessarily cover all possible circumstances that must be controlled.
Piranha solution is used frequently in the microelectronics industry, to clean, for example, photoresist from silicon wafers. It is used in scientific research to make highly hydrophilic surfaces. It is sometimes used to passivate glassware prior to doing sensitive chemical reactions. Unlike chromic acid solutions, piranha will not contaminate glassware with heavy metal ions.
There are two different piranha solutions: The most common is the acid piranha: a 3:1 mixture of concentrated sulfuric acid (H2SO4) with hydrogen peroxide (H2O2). The other is base piranha: a 3:1 mixture of ammonium hydroxide ( NH4OH) with hydrogen peroxide (H2O2). Both are equally dangerous when hot, although the reaction in the acid piranha is self-starting whereas the base piranha must be heated to 60 degrees to initiate.
Acid piranha is a mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2), used to clean organic residue off of substrates. Because the mixture is a strong oxidizer, it will remove most organic matter, and it will also hydroxylate most surfaces (add OH groups), making them extremely hydrophilic (water compatible).
Piranha is considered a “Highly Reactive Substance”. As such, all labs making or using piranha must have:
In addition, all labs using piranha must have:
All persons working in GT labs are required to dress appropriately per the GT Appropriate Attire and Personal Protective Equipment Policy including:
Many people are unaware that the most mundane of powdery materials (dusts) can ignite and even explode under the right set of conditions: A dust explosion is the fast combustion (deflagration) of dust particles suspended in the air in an enclosed location. Coal dust explosions are a frequent hazard in underground coal mines, but dust explosions can occur where any powdered combustible material is present in an enclosed atmosphere. There are four necessary conditions for a dust explosion: A combustible dust; the dust is suspended in the air at a high concentration; there is an oxidant (typically atmospheric oxygen); and there is an ignition source. A fifth favorable, but not strictly necessary condition is that the dust be confined.
Many materials which are commonly known to oxidize can generate a dust fires or explosions, such as coal, sawdust, and magnesium. However, many otherwise mundane materials can also lead to a dangerous dust cloud such as grain, flour, sugar, powdered milk and pollen. Many powdered metals (like aluminum and titanium), can form ignitable/explosive suspensions in air. On Feb 8, 2008, a dust explosion in Port Wentworth, GA, leveled a sugar refinery, killed 6 workers, and injured 44 others. In May of 2009 a mostly empty jar containing metal and resin powders caught fire in the hand of a Georgia Tech researcher while she shook it to loosen the powder stuck to the side of the jar; she was not injured.
For ignition to occur, dust must also consist of very small particles, presenting a large surface area, allowing it to support combustion. Dust is defined as powders with particles less than about 500 micrometers in diameter, but finer dust will present a much greater hazard than coarse particles by virtue of the larger surface area.
Different dusts will have different combustion temperatures and dust of various types will either suppress or elevate this temperature in relation to the stoichiometric concentration of the dusts. It is necessary that sufficient energy, generally either thermal or electrical, be applied to trigger combustion. Due to the small volume in relation to the large surface area, combustion can then proceed very rapidly and the flame front can also travel quickly. For example, 1 kg of powder, 120 µm in diameter will have a surface area of 50 m² or 540 sq ft. Due to the thermal expansion of the gas, the pressure increases. In an enclosed space this leads to the over pressurization of the “container” which could be a jar in a laboratory or an entire building, causing it to burst or “explode”.
In December of 2008, a young researcher at UCLA was badly burned while working with tertiary (t) - butyl lithium. She died as a result of her burns a few weeks later. T-butyl lithium and other organometalic compounds are very reactive; many are also pyrophoric and ignite spontaneously upon exposure to air. Due to the potential risks involved in working with organometallics and pyrophoric materials, it is especially important to assure that all possible steps have been taken to prevent mishaps while handling these materials:
Pyrophoric materials are on the GT Restricted Purchases list (http://www.ehs.gatech.edu/chemical/pre_approval.pdf ): please complete the Pre-notification form and contact GT EHS Laboratory and Chemical Safety Manager before acquiring any pyrophoric material that you have not used previously at Georgia Tech. The acquisition must be approved by the Georgia Tech Chemical and Environmental Safety Committee before you may proceed.
To help with the approval process, please provide a copy of your Standard Operating Procedures for working with the material in question which describe
Additional rules regarding the use of pyrophoric gases can be found in the Georgia Tech Dangerous Gas Safety Program.
Transfers of liquid materials involving more than 10 mL shall only be accomplished by the double tipped needle method.
Organic Peroxides and Peroxide forming chemicals are classified as Potentially Explosive Chemicals (PECs) under Chematix, the computer program used by Georgia Tech to track and manage chemicals. An organic peroxide is any organic (carbon-containing) compound having two oxygen atoms joined together (-O-O-). This chemical group is called a "peroxy" group. The main hazards related to organic peroxides are their fire and explosion hazards. Most undiluted organic peroxides can catch fire easily and burn very rapidly and intensely. This is because they combine both fuel (carbon) and oxygen in the same compound. Some organic peroxides are dangerously reactive. They can decompose very rapidly or explosively if they are exposed to only slight heat, friction, mechanical shock or contamination with incompatible materials. See the section on Chemical Storage for more information on peroxide forming chemicals and how EHSA can help you manage them safety.
Oxidizing materials are liquids or solids that readily give off oxygen or other oxidizing substances (such as hydrogen peroxide, nitrates, nitrites, and permanganates). They also include materials that react chemically to oxidize combustible (burnable) materials; this means that oxygen combines chemically with the other material in a way that increases the chance of a fire or explosion. This reaction may be spontaneous at room temperature or may occur under slight heating. Oxidizing liquids and solids can be severe fire and explosion hazards. See the Section on Storing Chemicals- Oxidizers for more information.
Acquisition of explosive polynitro compounds is restricted under Georgia Tech Rules and may involve permitting under Federal Regulations and/or Georgia State Fire Safety Regulations, even if limited to “Laboratory Quantities”. Please contact EHS at 404-894-4635 before purchasing or agreeing to accept these materials from outside Georgia Tech or from other Georgia Tech researchers.
Teflon or other nonmetal spatulas must be used with solid sodium azide due to its reactivity with metals.
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