Chemical Specific Guidance

Aqua Regia

Aqua Regia is a fresh mixture of hydrochloric and nitric acids used to etch metals and clean glassware.  It is very corrosive to skin and respiratory tract. It needs to be mixed fresh for each use and evolves gasses which have caused many accidents and container ruptures.  It should be used only when absolutely necessary.  For detailed use instructions you must develop your own SOP for your process by reviewing this detailed  factsheet.



Asbestos is a naturally occurring mineral fiber extensively used in building materials from the 1930's until the 1970's. It is resistant to heat, mechanical stress, and water. Asbestos fibers are only a hazard when they become airborne and are inhalable. Please visit our additonal pages for more information regarding asbestos or emergency release of asbestos.


Cyanide Salts Safety Guidelines

Cyanide salts (sodium and postassium) have a white crystalline or powder appearance.  They are highly toxic by inhalation, ingestion, and can even be absorbed through the skin.  As little as 50 mg can be fatal to a human being.  Mixing dry salts with atmospheric moisture or with acids can release poisonous hydrogen cyanide gas which can be fatal.  MIT Procurement will not allow you to purchase cyanide salts unless the EHS Office approves your order.  You must follow all the EHS guidelines to use these materials, available here.



Hydrofluoric Acid

  • Hydrofluoric Acid Hazards  Hydrofluoric acid (HF) is a particularly hazardous substance, like many acids, but has added dangers that make it especially dangerous.  It  is less dissociated than most acids and deeply penetrates the skin.  Symptoms of exposure may be delayed for up to 24 hours, even with dilute solutions.  HF burns affect deep tissue layers, are extremely painful, and disfiguring.  The highly rective fluoride ion circulates throughout the body and can cause multiple organ toxicity, including heart arrhythmias and death, if not treated.  Any suspected exposures to HF should be immediately flooded with water, decontaminated with calcium gluconate gel, and treated at MIT Medical.
  • Hydrofluoric Acid Training  All employees are required to be trained by the EHS Office before beginning work with HF.  The training covers safe use, personal protective equipment, and decontamination procedures.  The training can be taken on the web or in the classroom.  Please go to Atlas and select Learning Center to search and register for the training.  All laboratories using HFmust have unexpired calcium gluconate decontamination gel on hand.  The gel can be obtained at no cost from the EHS Office at 617-452-3477.


Perchloric Acid

  • Danger: Heated Perchloric Acid can only be used in a fume hood with a functioning water wash down.  EHS has one of these hoods and there are others on campus  Contact EHS at 617-452-3477 if you need access to such a hood.
  • General Hazard Description: Perchloric acid is a clear odorless liquid that is stable at room temperature.  It is highly corrosive to all tissues and a strong oxidizer that reacts violently with a wide variety of substances, including organic materials, alcohols, amines, strong acids, strong bases, etc.  Contact with wood, paper, and other cellulose products may lead to explosions.  Avoid heat as it may form explosive peroxides at elevated temperatures.
  • Perchloric acid reactions above room temperature should only be carried out in a dedicated fume hood with a functioning water wash-down.  Please review the SDS and EHS SOP before working with perchloric acid.
  • Decommissioning Fume Hoods: All fume hoods and related ductwork should be checked for explosive perchlorates before dismantling these systems.  Call the EHS Office at 617-452-3477 to conduct this test.


Piranha Solutions

  • Piranha solutions are strong oxidizers used to remove small amounts of organic residues from electronic components.  The most commonly used solution at MIT is a 3:1 mixture of sulfuric acid and hydrogen peroxide.  The solutions are mixed together just before use: The reaction is extremely exothermic.  Solution temperatures quickly rise to greater than 100 oC and generate significant quantities of gasses.  Piranha solutions are incompatible with other acids and organic materials such as alcohols and photoresists.  The solutions are very corrosive to eyes, skin, and respiratory tract.
  • There have been multiple incidents in MIT labs where containers have ruptured due to the use of non-venting caps or mixing spent piranha with incompatibles such as isopropanol. In one instance, the glass bottle exploded and scattered glass throughout the lab.  Fortunately there was no one in the lab at the time of the explosion.
  • Piranha solutions should never be used in air tight containers.  Vented caps, which are available at no charge from the EHS Office, should always be used.  Piranha waste should never be mixed with other chemicals.  Before using this material, please consult the detailed EHS Chemical Fact Sheet for Piranha Solutions.



  • Formaldehyde is classified by OSHA as a Particularly Hazardous Substance, a probable carcinogen, and a respiratory and skin sensitizer. It has a strong odor detectable at 0.04 to 1 parts per million (ppm). The OSHA 8 hour Permissible Exposure Limit is 0.75 ppm. The 15 minute Short Term Exposure Limit is 2 ppm.
  • Formaldehyde can be used safely provided that the following precautions are followed:
    • Use in a fume hood or other ventilated enclosure such as a dissection hood or ventilated downdraft table unless very dilute or small quantities.
    • Wear gloves with good resistance to formaldehyde, such as the disposable nitrile Best NDex glove. Latex gloves provide short term splash resistance only and should generally not be worn for formaldehyde work.
    • All formaldehyde waste should be collected and disposed of as hazardous waste.
    • The Chemical Hygiene Lab Specific Training for your lab should cover formaldehyde hazards and safe use practices
    • Call the EHS Office (617-452-3477) if you can smell formaldehyde during your procedures. 
    • Make an appointment with the MIT Medical Department (617-253-4481) if you experience any symptoms of eye, nose or throat irritation during your work with formaldehyde.
  • Formaldehyde OSHA Standard 1910.1048:  MIT must identify all laboratory activities that are above the OSHA action level or short term exposure level (STEL) through initial air monitoring and provide training, medical surveillance, and engineering and work practice controls if air levels warrant it. The Industrial Hygiene Program (IHP) in the EHS Office has performed extensive air sampling for formaldehyde during a variety of lab activities such as animal perfusion, dissections, and tissue fixation and found the results to be below OSHA levels provided that suitable exhaust ventilation is used.
  • Contact EHS for evaluation: With proper exhaust ventilation, you should not detect any odors from formaldehyde work nor experience any symptoms of exposure such as eye tearing or throat irritation.  If you do, please contact EHS immediately at (617) 452-3477 for an evaluation. EHS sends a questionnaire annually to laboratory EHS Representatives to survey formaldehyde use and conducts air sampling of procedures where there may be a potential for exposure.  Notify EHS for an evaluation if your procedures change and you work with large quantities of formaldehyde, perform animal perfusions, or do extensive tissue dissection work.



  • Beryllium metal and its alloys are used in a wide variety of industrial products because they are light and resistant to heat, stress and strain. Beryllium is highly toxic to the lungs and is a confirmed human carcinogen.  All procedures that may be an exposure hazard should be evaluated by the EHS Office to insure that air concentrations are within acceptable levels.  The ACGIH TLV for beryllium is 0.05 ug/m3. The OSHA PEL is 0.2 ug/m3.  All employees with potential for exposure can enroll in the annual medical surveillance program sponsored by MIT Medical Department.
  • Health Effects
    • The inhalation of dust, fumes or mists containing beryllium or beryllium compounds present a very serious health hazard. Laboratory processes that can produce fumes or inhalable dust include heating, grinding, and machining of beryllium and its alloys.
    • In humans, beryllium causes both acute and chronic lung disease and lung cancer.  Acute beryllium disease has been seen after brief exposures to soluble beryllium compounds.  Symptoms range from mild inflammation of nasal passages to bronchitis and lung inflammation.  Chronic beryllium disease is characterized by lung fibrosis (scarring) and inflammation, causing breathlessness upon exertion, weakness, chest pain, enlarged heart, and ultimately death.  Beryllium has been documented to cause lung cancer in industrial beryllium production facilities.  Beryllium can also cause allergic skin reactions.
  • Safe Work with Beryllium
    • To work safely with beryllium, all labs and shops must do the following:
    • All procedures that potentially generate beryllium particulate such as heating or machining or aerosols of beryllium salts must be evaluated by the EHS Office to insure that air levels are safe.
    • All researchers working with beryllium in a manner that creates airborne exposure can enroll in the Beryllium Surveillance Program at MIT Medical by calling (617) 452-3477. The program is voluntary and free.
    • Standard operating procedures for specific operations should be established before working with beryllium and its compounds.  These will normally include use of fume hoods or local exhaust ventilation. 
    • Prior to working with beryllium, employees must receive training by their supervisor.  Beryllium users must also complete either Chemical Hygiene or Hazard Communication training and Managing Hazardous Waste training.
  • For additional information about safe work practices (including use of respirator, gloves, clothing, etc) please consult the MIT Beryllium Policy and Procedures .


Nanomaterial Safety

  • Definition and Characteristics: Nanomaterials are defined by the ASTM as a material with two or three dimensions between 1 to 100 nm. They can be composed of many different base materials (carbon, silicon, and metals such as gold, cadmium, and selenium).  They can also have different shapes:  such as nanotubes, nanowires, crystalline structures such as quantum dots, and fullerenes.  Nanomaterials often exhibit very different properties from their respective bulk materials: greater strength, conductivity, and fluorescence, among other properties. 
  • Toxicity: The toxicity of most nanomaterials is currently unknown.  Preliminary toxicity testing has indicated that some nanoparticles may be more toxic than the corresponding micron sized particle because of their greater surface area and reactivity.  Nano-sized titanium dioxide produces 40 fold more lung inflammation than micron-sized particles.  In preliminary tests, carbon nanotubes have produced lung inflammation and fibrosis similar to crystalline quartz and asbestos.  Nanoparticles are similar in size to viruses and are easily taken up by the body’s cells, translocate around the body, and can possibly pass into the brain and through the skin.
  • Safe Work Practices and Proper Disposal:  The MIT EHS Office considers nanoparticles that have the potential for release into the air to be handled as particularly hazardous substance because their toxicity is, for the most part, unknown and early studies have been suggestive of toxic effects.  In the future, many types of nanoparticles may turn out to be of limited toxicity but precaution must be used until we know more.  The following best practices should be followed:
    • Work with nanoparticles that may release particles should be conducted in enclosures, fume hood, glove boxes, and other vented enclosures. 
    • All work should be done with gloves (at a minimum disposable nitrile gloves)
    • Currently, nanoparticles and solutions containing them are being disposed of as hazardous waste. Label all containers of nanomaterials (including waste) with the designation “nano”.
    • Detailed information on best laboratory practices for working with nanomaterials can be found at: University_Best_Practices.pdf
    • A checklist for developing your laboratory Standard Operating Procedure for nanomaterials work can be found at: Checklist_Developing_Nanomaterials_SOP.pdf
    • A review of the toxicity of some major categories of nanomaterials is at: Nanomaterial toxicity.This article also lists good reference sources for researchers to consult to keep up with toxicity information on their materials as it develops. 
    • Please call the EHS Office at 617-253-0344 for exposure evaluation of experimental setups and additional information.
  • Training on Nanomaterial Health and Safety
    • EHS has developed a web-based training on the health and safety of nanomaterials, which includes information on toxicity of different types of nanomaterials and laboratory practices to prevent exposures. 
    • Please go the following link for a self-paced course:  [link to Articulate course]
    • A pdf of resources can be found here:  [link to pdf]
    • A powerpoint of the slides can be found here [link to pptx]
    • If you have any questions after reviewing these materials, please contact the EHS Office at or 452-3477.  An EHS Officer can also visit your lab for a review of your procedures.
  • Nanoenclosures: Nanomaterials can be handled in fume hoods, biosafety cabinets and other exhausted enclosures. However these hoods often have high air velocities that can be disruptive to handling dry, lightweight nanomaterials. Laboratories in Mechanical Engineering and Center for Materials Science and Engineering have purchased a specially designed type of enclosure for handling nanopowders.  This type of enclosure differs from a traditional fume hood in that the slots for exhausted air are located above the floor of the unit.  Therefore air currents do not disturb the handling of light, fluffy nanopowders or nanotubes.  These units were originally developed to enclose sensitive balances but can be used either to weigh nanomaterials or manipulate samples.  Contact EHS for vendors who supply these enclosures.



  • Lead can be found in many places on campus, including paint, solder, ceramic products and water. MIT is committed to providing students and employees with safe work environments free from any health hazards, to that extent, we comply with pertinent Federal and State guidelines and regulations. Such regulations require the identification of lead-containing materials, maintaining painted surfaces, effective and proper abatement when necessary, and proper disposal of waste generated by the abatement project.
  • Lead and its compounds are toxic and present a health hazard when ingested or inhaled. Once absorbed it is carried throughout the body by the blood stream to other organs. Excessive lead levels can result in damage to the brain, kidney, CNS, blood and reproductive systems. Lead is extremely hazardous to children because it is easily absorbed into their bodies and interferes with the developing brain, central nervous systems and other organs. Lead is excreted mainly through the urinary and GI tract. Not all the lead is excreted though; some is absorbd in the bones.



  • Mercury is a naturally occurring element that is found in air, water and soil. It exists in several forms: elemental or metallic mercury, inorganic mercury compounds, and organic mercury compounds.
  • When elemental mercury is spilled or a device containing mercury breaks the exposed mercury volatizes at room temperature and becomes an odorless toxic vapor. Mercury vapors will increase in warm or poorly-ventilated rooms or spaces.
  • Mercury and its compounds penetrate the intact skin. Wear nitrile, PVC or natural rubber gloves for elemental mercury and for organo-alkyl compounds use Silver Shield or 4H gloves and an outer glove of heavy duty nitrile or neoprene.
  • The nervous system is very sensitive to all forms of mercury. Methylmercury and metallic mercury vapors are more harmful than other forms, because more mercury in these forms reaches the brain.
  • Exposure to high levels of metallic, inorganic, or organic mercury can permanently damage the brain, kidneys, and developing fetus.


Polychlorinated Biphenyl

  • PBCs refer to a class of chemicals consisting of 2 aromatic hydrocarbon rings (phenyls), where each hydrogen position on the carbon ring can be substituted with a chlorine atom.  As the number of chlorine atoms on the ring increase so does the stability and thermal resistance properties. 
  • PCBs have joined a class of regulated materials called PBTs: persistent, bio-accumulative, and toxic chemicals. PCBs do not degrade readily in the environment (persistent)
  • PCBs concentrate in the fatty tissues of organisms, and doses are amplified with each step in the food chain (bio-accumulative)
  • PCBs can cause chloracne
  • Although MIT made a concerted effort to dispose of PCB containing items and electrical equipment in the late 1980s, it is possible that an item pre-dating 1980 may surface when a space is cleaned for a lab move or a renovation.  If you are unsure of the date of manufacture of any oil-containing equipment, please contact EHS.