Chemicals

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 a 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.

To work safely with beryllium, all labs and shops must do the following:

• All procedures that potentially generate beryllium particulates, 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 Health 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 the use of fume hoods or local exhaust ventilation.
• Prior to working with beryllium, employees must receive training from their supervisor. Beryllium users must also complete either Chemical Hygiene or Hazard Communication training and Managing Hazardous Waste training.

Best practice for dispensing liquid from a low pressure container to a dewar:

• Don a face shield and safety glasses, cryogenic gloves, long pants without cuffs, closed-toed shoes, and a laboratory coat.
• Next connect a transfer line to the liquid valve, if one is not already present, making sure the fittings match.  Please note that the valve will be labeled.  The transfer line should have a phase separator attached to reduce turbulence and the release of gas while filling.
• Check the pressure in the cylinder.  It should read approximately 22 pounds per square inch.  Position the Dewar on the floor at the base of the cylinder, or on some other support below waist level and insert the transfer line into the Dewar.  The end of the transfer line should extend to the bottom, or just off the bottom, of the Dewar.  Keep bystanders at least four feet away while filling in case of splashing.
• Open the liquid valve one half to three quarters of a turn to begin cooling down the transfer hose and adding the cryogen to the Dewar.  The warm hose and Dewar will vaporize the cryogen as it cools and this could create splashing particularly if it is added too quickly.  The pressure in the container will drive the liquid out through the valve.
• Once the hose and Dewar have cooled, open the liquid valve to obtain the desired rate of flow.  However, if you fully open the valve, be sure to close it a quarter turn.  A fully opened valve may freeze in that position causing a spill.  A good flow rate is typically evident by a moderate vapor trail coming from the mouth of the Dewar.  Listen for the change in sound as the Dewar fills – a higher pitch indicates the Dewar is getting full.
• When full, close the liquid valve. Remove the transfer line but be careful not to drop it or allow the phase separator to hit a solid object which will cause it to break.  Watch out for any cryogen that continues to spill out of the transfer hose.   Finally, place the top on the Dewar, pushing it all the way on and then pulling it up so that it is loose.

Best practice for dispensing gas from a high pressure container to equipment or system:

• Don cryogenic gloves, safety glasses, long pants without cuffs, closed-toed shoes, and a laboratory coat.
• Check the pressure in the cylinder.  It should be approximately 230 pounds per square inch, but this will vary with the gas dispensed.
• Next connect the inlet of a suitable regulator to the gas use valve or a transfer line from this valve to an appropriate wall mounted regulator.  Please note that the gas withdrawal valve will be labeled. The regulator should be designed for use with cryogens and adjustable over the desired pressure range.
• The outlet of the regulator is connected to the system receiving the gas using the appropriate transfer line – in this case it’s a dedicated gas line.
• Next close the regulator valve and open the gas use valve.  Adjust the gas regulator to deliver the gas at the desired pressure, for example, 90 pounds per square inch.   At this point you may begin withdrawing gas.
• In applications where large volumes of gas will be withdrawn from the container, the pressure building valve will be opened.  This valve operates an internal circuit that allows more liquid to vaporize then would naturally occur through evaporation alone.  The vendor supplying the container generally knows your application and opens or closes this valve when delivered.

The transportation of cryogenic containers in elevators represents a potential asphyxiation risk if researchers become trapped in an elevator with a container of cryogen.  If a passenger elevator must be used, the first person rolls the container into the elevator, posts a clearly visible sign that warns staff and students not to enter the elevator.  The first person pushes the elevator button for the appropriate floor and immediately gets off the elevator.  The second person meets the elevator, removes the container and the sign.

This table lists the change in volume as the gas transitions from liquid to gas at room temperature. The resulting pressure that would be generated inside a container from trapped liquid under these conditions is also listed.

Note 1: Although CO2, which has a slightly higher boiling is technically not cryogenic liquid but has similar properties and is often included in this category. (Note: Source Argonne National Laboratory)

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.

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.

Any suspected exposure to HF should be immediately flooded with water, decontaminated with calcium gluconate gel, and receive medical attention immediately. To do so, call 100 from a MIT phone or 617-253-1212 from a cell phone. An alternative response for an exposure may be indicated in a written SOP only after consultation with EHS and MIT Health.

All laboratories using HF must have unexpired calcium gluconate decontamination gel on hand. You may obtain it from the EHS Office by completing this form.

Calcium Gluconate Gel Request Form

All personnel 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.  

To register or complete the training via the web, visit MIT Atlas (certificate login required) and follow these steps: 

1. Search for and select the Learning Center.  
2. Under the My Profile tab, click the “Create EHS Profile” or “Update PI / Activities” button.  
3. Select “Save and Continue.” 
4. On the Select Your Activities page, scroll down to the Chemical Safety section. Check the box for “Use or work in the area that store or uses hydrofluoric acid.”  
5. Click the “Submit” button at the bottom of the page.  
6. Options for completing the training will appear under the My Training Needs tab. This training can be completed via a classroom training or web course.  

Upon completion of your experiment using lithium or sodium metals or powders, specifically, follow these guidelines or contact the EHS Office for assistance in preparing the waste or surplus materials for hazardous waste pick-up:

1. Within the glove box or controlled environment, containerize your waste materials and submerge them in oil.
2. Remove the container of waste from the glove box, label it with a red tag, spell out the constituents, indicate Ignitable/Reactive as the associated hazards, date the container, and place it in your lab’s SAA.
3. Upon dating, place a waste collection pickup request online for removal from the lab within 3-days.

Particles in the nanometer size range do occur both in nature and as an incidental byproduct of existing industrial processes. Nanosized particles are part of the range of atmospheric particles generated by natural events such as volcanic eruptions and forest fires. They also form part of the fumes generated during welding, metal smelting, automobile exhaust, and other industrial processes. One concern about small particles that are less than 10 um is that they are respirable and reach the alveolar spaces of the lungs.

The ability to be taken up by cells is being used to develop nanosized drug delivery systems and does not inherently indicate toxicity.

The toxicity of most nanomaterials is currently unknown. Studies suggest that the levels of toxicity depend on the base material of the nanoparticle, its size and structure, and its substituents and coatings.

The preliminary conclusions to be drawn from the toxicology studies to date is that some types of nanomaterials can be toxic, if they are not bound up in a substrate and they are available to the body. Multiple government organizations are working to fund and assemble toxicology information on these materials. In the interim, MIT researchers must use procedures that prevent inhalation and dermal exposures because at this time nanotoxicology information is limited.

Translocation in the Body

Once in the body, some types of nanoparticles may have the ability to translocate and be distributed to other organs, including the central nervous system. Silver, albumin, and carbon nanoparticles all showed systemic availability after inhalation exposure.

Significant amounts of 13C labeled carbon particles (22-30 nm in diameter) were found in the livers of rats after 6 hours of inhalation exposure to 80 or 180 ug/m3 (Oberdorster et al. 2002). In contrast, only very small amounts of 192Ir particles (15 nm) were found systemically. Oberdorster et al. (2004) also found that inhaled 13 C labeled carbon particles reached the olfactory bulb and also the cerebrum and cerebellum, suggesting that translocation to the brain occurred through the nasal mucosa along the olfactory nerve to the brain.

The ability of nanomaterials to move about the body may depend on their chemical reactivity, surface characteristics, and ability to bind to body proteins.

Handling Nanoparticles

Nanomaterials of uncertain toxicity can be handled using the same precautions currently used at MIT to handle toxic materials: use of exhaust ventilation (such as fume hoods and vented enclosures) to prevent inhalation exposure during procedures that may release aerosols or fibers and use of gloves to prevent dermal exposure. The EHS Office will continue to review health and safety information about nanomaterials as it becomes available and distribute it to the MIT community. 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.

If you work with nanomaterials in your lab, register your laboratory and your nanomaterials in the Nanomaterial program.

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”.
• develop your laboratory Standard Operating Procedure for nanomaterials work
• Call the EHS Office at 617-452-3477 for exposure evaluation of experimental setups and additional information.

EHS has developed a web course, Nanomaterials Safety and Health (MIT Atlas Learning Center – requires certificates), which includes information on the toxicity of different types of nanomaterials and laboratory practices to prevent exposures.

If you have any questions after reviewing these materials, contact the EHS Office at environment@mit.edu or 617-452-3477. An EHS Officer can also visit your lab for a review of your procedures.

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.

As nanotechnology emerges and evolves, potential environmental applications and human health and environmental implications are under consideration by the EPA and local regulators.

EPA has a number of different offices coordinating its review of this rapidly evolving technology. The EPA is currently trying a voluntary approach to testing and developing a stewardship program. There are currently no guidelines from the EPA specifically addressing the disposal of waste nanomaterials. It seems that regulation at some level is inevitable. Some political subdivisions, including the City of Cambridge, are already evaluating local regulation.

MIT is taking a cautious approach to nano waste management. It is our belief that regulation is inevitable. In order to better understand the potential volumes and characteristics of these waste streams, we are advising that all waste materials potentially contaminated with nanomaterials be identified and evaluated or collected for special waste disposal.

The following waste management guidance applies to nanomaterial-bearing waste streams consisting of:

• Pure nanomaterials (e.g., carbon nanotubes)
• Items contaminated with nanomaterials (e.g., wipes/PPE)
• Liquid suspensions containing nanomaterials
• Solid matrixes with nanomaterials that are friable or have a nanostructure loosely attached to the surface such that they can reasonably be expected to break free or leach out when in contact with air or water, or when subjected to reasonably foreseeable mechanical forces.

The guidance does not apply to nanomaterials embedded in a solid matrix that cannot reasonably be expected to break free or leach out when they contact air or water, but would apply to dusts and fines generated when cutting or milling such materials.

DO NOT put material from nanomaterial – bearing waste streams into the regular trash or down the drain. Before disposal of any waste contaminated with nanomaterial, call the EHS Office (45(617) 452-3477) for a waste determination.

Collect paper, wipes, PPE, and other items with loose contamination in a plastic bag or other sealing container stored in the laboratory hood. When the bag is full, close it, take it out of the hood and place it into a second plastic bag or other sealing container. Label the outer bag with the laboratory’s proper waste label. On the Contents section, note that it contains nano-sized particles and indicate what they are.

Currently, the disposal requirements for the base materials should be considered first when characterizing these materials. If the base material is toxic, such as silver or cadmium, or the carrier is a hazardous waste, such as a flammable solvent or acid, clearly they should carry those identifiers. Many nanoparticles may also be otherwise joined with toxic metals of chemicals. Bulk carbon is considered a flammable solid, so even carbon-based nanomaterials should be collected for determination as hazardous waste characteristics.

• Gradient Corp. Monthly EH&S Nano News
• National Institute for Occupational Safety and Health (NIOSH)
• National Nanotechnology Infrastructure Network (NNIN)
• National Center for Biotechnology Information (NCBI) Pub Med – Search for articles on nanoparticle toxicity
• Safe Nano (UK) – Regularly updated website on health and safety risks of nanotechnology with comments by toxicologists and regulators

Many factors must be considered when determining what controls are required, including but not limited to the specific pyrophoric chemical(s) being used, type of application, and other hazards. For example, semiconductor research can involve pyrophoric materials that are also highly toxic, requiring additional controls. Contact your EHS Coordinator or the EHS Office for more specific guidance on appropriate controls based on your lab’s research.

Depending on the materials and process, pyrophoric and water-reactive materials should be used in a chemical fume hood (over a spill tray) using techniques that prevent the material from contacting air or in an inert-atmosphere glove box according to the manufacturer’s recommendations.

Before using pyrophoric reagents refer to the Aldrich Technical Bulletins AL-164 and AL-134, which provide detailed instructions on using standard syringe and double-tipped needle transfer techniques to prevent contact with air. Some pyrophoric and water-reactive materials must be handled in a gas-tight syringe to prevent exposure to air.

Flame resistant (FR) lab coats are required when handling pyrophoric substances, including chemicals that release flammable gases that may ignite spontaneously and self-heating chemicals that may catch fire outside of a glove box. FR lab coats should also be worn when working with chemicals that react violently with water or release flammable gas, or when performing potentially vigorous reactions.

Protective eyewear is required when handling pyrophoric and water-reactive materials. Fully enclosed safety goggles or a face shield are preferred, as they offer greater facial protection than safety glasses.

Gloves are required when handling pyrophoric and water-reactive materials. It is recommended that Nomex gloves be worn between two pairs of nitrile gloves for fire protection purposes.

Clothing made from polyester and other synthetic fabrics and loose clothing should not be worn. Always wear long pants and closed toe shoes within the lab. Loose or long hair should be tied back to prevent ignition in the event of a flash fire.

The best way to determine if the substance you are working with is pyrophoric or water reactive is to review the Safety Data Sheet.  Safety Data Sheets for all chemicals in a laboratory space must be immediately available.  Safety Data Sheets should be updated, reviewed periodically, and used as part of lab specific training.

Common pyrophoric materials include metal hydrides, non metal hydrides, metal halides, alkali metals, metal carbonyls, and metal powders.Note that this list includes examples of pyrophoric and water-reactive materials but is not comprehensive.

Downloadable PDF with hazard details

Many metal powders present special storage and handling concerns when finely divided, including hazards such as air- or water-reactivity or explosive dust generation. Whether a given metal powder exhibits these properties depends on multiple factors, including but not limited to particle size, surface area, moisture level, purity, etc.

Please contact your EHS Coordinator or the  EHS Office for assistance when working with small-particle-size metal powders.

Excess pyrophoric chemicals should be treated as hazardous waste. Due to their properties special procedures may be required for waste collection and labs may incur disposal fees based on factors outlined below.

Contact EHS if several bottles are removed from storage at one time, as a fee may be applied depending on the volume. The more toxic and hazardous the chemical and the larger the bottle, the higher the cost tends to be.

Nonreturnable pyrophoric gas cylinders will also incur a cost at the time of disposal. Contact EHS for disposal rates and information on the removal process.

Certain metal powders, such as fine aluminum powder, should be submerged in oil prior to waste collection from the lab. Debris with aluminum powder may be collected with a thin coating of oil and kept separate from other debris waste streams.

Reactive metals, such as lithium, potassium and magnesium, should also be submerged under oil and handled as hazardous waste. Contact EHS for additional guidance.