Image is Everything: MRI and Helium Safety

 

MRI

Magnetic resonance imaging (MRI) is a diagnostic procedure that uses a combination of a very large magnet, radio waves, and a computer to produce detailed, cross-sectional, and three-dimensional images of organs and structures within the body.

An MRI scan is a valuable diagnostic tool that can show injuries or other anomalies that cannot be seen in a CT scan or X-ray.  For instance, soft tissue injuries, such as,strains, sprains, contusions, tendonitis, and bursitis can all be observed via MRI.

Moreover, according to the Mayo Clinic, MRI can also be used to diagnose a variety of brain-related and nervous system disorders, including strokes, aneurysms, multiple sclerosis, eye and inner ear problems, and spinal cord injuries. MRI is widely used in research on brain structures and functions.

How MRI Works

MRI scanning machines vary in size, shape, and degree of openness but the typical MRI machine resembles a tube (encompassing a very large magnet) with a table in the middle, which enables the patient to lie down and slide into the magnetic field created inside the machine. The magnet itself is comprised of multiple coils of connective wire through which a current is passed to generate a magnetic field. To achieve the high field strengths required for most clinical needs, the magnet is cooled with liquid helium to -452 degrees Fahrenheit (-270 Celsius). The super cold temperature applied to the magnet provides for “superconductivity”, meaning that current can pass through the magnet’s coils without electrical resistance, producing the type of strong magnetic field necessary to produce detailed images.

To ensure accurate imaging, and to preserve the integrity of the MRI scanning machine, the liquid helium must be kept extremely cold when the scanner is in operation. If the temperature of the liquid helium were to rise above the very cold levels required for superconductivity, the helium might vaporize and,with the dissipation of the liquid helium’s super-cooling properties,  the machine’s magnet could overheat, potentially causing irreparable damage to the MRI machine.

Oxygen Monitors Can Detect Helium Leaks

Helium is an odorless, colorless, oxygen-depleting gas that can rapidly displace oxygen in the air to levels below what is needed to for humans to breathe. Excess exposure to helium can cause dizziness, nausea, and loss of consciousness, and could even result in death within seconds of exposure. Because liquid helium is devoid of color and odor, MRI personnel would, absent appropriate oxygen monitoring, likely be unaware that a potentially dangerous helium leak has occurred. As such, the National Institutes of Health’s Design Requirements Manual recommends that oxygen monitors be installed in MRI treatment areas.

Proper oxygen monitoring equipment should be placed in MRI rooms, as well as in storage rooms, and in any other site where helium gas may accumulate. The monitoring equipment should include visual and audible alarms that would be activated in the event of helium leaks and a decrease in oxygen levels.

PureAire Oxygen Deficiency Monitors

PureAire Monitoring Systems’ Sample Draw Oxygen Deficiency Monitor continuously tracks levels of oxygen and will detect helium leaks before MRI machines are damaged and the health of employees and patients is put at risk.

The Monitor’s built-in pump samples oxygen from up to 100 feet away,making it ideal for use in MRI facilities, because the metal components within the Monitor are outside the imaging area and, therefore, will not interfere with the magnets that are the heart of MRI scanning machines.

PureAire’s durable, non-depleting, zirconium oxide sensor can last 10+ years in a normal environment, without needing to be replaced.

In the event of a helium gas leak, and a decrease in oxygen to an unsafe, OSHA action level, the Sample Draw Oxygen Monitor will set off an alarm, complete with horns and flashing lights, alerting staff and patients to evacuate the area. Additionally, the same alarm will alert personnel to turn off the MRI scanner in order to prevent the magnet overheating that could result in possible damage to the machine.

PureAire’s Sample Draw Oxygen Deficiency Monitor has an easy to read screen, which displays current oxygen levels, for at-a-glance observation by MRI employees, who derive peace of mind from the Monitor’s presence and reliability.

What Are Hot Melt Adhesives? Why Are They Used and What Is the Importance Of Nitrogen Gas?

 Hot Melt Adhesives and Available Types Used in Industrial Manufacturing

Industrial hot melt adhesives are polymer-based thermoplastic resins that, when melted, are used to bond materials together. Hot melt adhesives are comprised of one or more base polymers combined with tackifiers (which provide stickiness to the adhesive), plasticizers (to provide greater flexibility), and antioxidants (for protection against degradation) to allow for stability, adhesion, and flexibility.

Industrial hot melt is available in a variety of forms, including granular or powder hot melt blocks, pellets, bags, cakes, drums, and pillows. These materials are solid at room temperature, and then heated, melted, and dispensed for a variety of industrial applications.  As the adhesive returns to room temperature, a strong bond is created, adhering the manufacturing components together.

Hot melt can be dispensed as a liquid or, by introducing an inert gas (such as nitrogen) to the hot melt, as a foam.

Industrial Hot Melt Applications

In either liquid or foam form, hot melt adhesive is used across a wide variety of industries including  aerospace; automotive; product assembly; furniture making, cabinetry, and upholstery; product packaging; book binding; and non-woven sanitary hygiene products.

Aerospace and automobile manufacturers utilize hot melt adhesives for potting electronics (a process used to protect sensitive components from impact or vibration), as well as sealing rivets, seams, and joints. Additionally, hot melt foam is used in airplanes and cars as insulation around doors and windows to reduce vibrations and noise, as well as in seat assembly.

The pages in books and magazines are kept securely bound together using HMAs. The packaging industry depends on a strong adhesive bond to keep the flaps of corrugated boxes and cartons securely closed.

Non-woven personal hygiene products are manufactured by utilizing hot melt adhesives throughout the manufacturing process, including adhering the elastic strands in the leg openings and waistbands, bonding the fabric layers together to secure and stabilize the wetness core, and affixing the fastening tapes to the waistband.

Charring

Charring is akey concern when working with hot melt adhesives, as char (degraded adhesives that have oxidized, hardened into a gel, and been blackened and burned) can negatively affect the adhesives, cause equipment failure, and lead to a shut-down in production.

Key causes of charring include overheating (typically as a result of either using a temperature that is too high for a particular hotmelt, excessive heating times, or incorrect melt tank size); oxidation (exposing the adhesives to too much oxygen), and contamination (from dirt, dust and other materials that fall into the hotmelt and burn).

Once formed, the char can break off into pieces that may clog filters and stop up spray and bead nozzles. The pieces of char can work their way onto the materials to be bonded, leaving marks, streaks, and uneven surfaces. Eventually, bits of char may get into hoses and pumps, breaking seals and scoring and damaging hoses and pump walls.

Why Nitrogen is Used for Hot Melt Adhesive

To reduce potential damage from charring, hotmelt operators may elect to blanket the adhesives with nitrogen (N2) in a process by which nitrogen, an oxygen depleting gas, is piped into the space between the hotmelt adhesive and the top of the hopper or melt tank. The nitrogen blanket protects the adhesive by creating a barrier against falling debris, and it also removes oxygen and moisture which may cause the hotmelt to oxidize and form char .

Oxygen Monitors Improves Quality Control and Helps Protect Employees

To preserve the integrity of the hot melt while blanketing with nitrogen, employees must maintain proper oxygen levels within hoppers or melt tanks, as too much oxygen can cause oxidation. Proper oxygen monitoring equipment should be placed inside melt tanks to measure and control oxygen levels.  A nitrogen leak could lead to failure of the nitrogen blanket, which could compromise the integrity of the adhesives.

Moreover, wherever nitrogen is used, the possibility of nitrogen leaks poses potential risks to humans. Since nitrogen displaces oxygen, a leak could deprive the air of oxygen, thereby creating a possible health hazard for personnel. When there is not enough oxygen in the air, persons working in the area can become disoriented, lose consciousness, or even suffocate due to the lack of oxygen. Since nitrogen lacks color and odor, there is no way, absent appropriate monitoring, for employees to detect a leak.

Best practice calls for oxygen deficiency monitors to be installed anywhere there is a risk of gas leaks. As such, oxygen monitors should be placed wherever nitrogen is stored, and in all areas where nitrogen is used.

PureAire O2 Deficiency Monitors

PureAire Monitoring Systems’ line of Oxygen Deficiency Monitors and Water Resistant Sample Draw Oxygen Monitors continuously track levels of oxygen and will alert hotmelt personnel to nitrogen leaks before employees’ health is put at risk.  In the event of a nitrogen gas leak, and a decrease in oxygen to an unsafe level, the monitor will set off an alarm, complete with horns and flashing lights, alerting employees to evacuate the area.

PureAire’s Water Resistant Sample Draw Oxygen Monitor is a self-contained oxygen deficiency system that is suitable for remote sampling of oxygen levels in confined spaces, hotmelt tanks, and other locations where remote oxygen monitoring is required. The built-in pump samples oxygen levels from up to 100 feet away.

PureAire oxygen monitors measure oxygen 24/7, with no time-consuming maintenance or calibration required. Built with zirconium oxide sensor cells to ensure longevity, PureAire’s O2 monitors can last, trouble-free, for over 10 years under normal operating conditions.Each PureAire O2 monitor has an easy to read screen, which displays current oxygen levels, for at-a-glance readings by hotmelt manufacturers, who derive peace of mind from the monitor’s presence and reliability.

Tunnel Freezing and Flash Freezing Food with Nitrogen: Oxygen Monitors and Why They May Required

New developments in cryogenic freezing are transforming the frozen food industry by making it easier to freeze all sorts of items quickly while retaining the highest nutritional value. Cryogenic and tunnel freezers are easy to use, yet they pose a hidden health risk. Learn why you may need an O2 monitor if your frozen food manufacturing facility relies on cryogenic freezers.

                                                              

How Cryogenic Freezers Work

Cryogenic freezers allow for continuous freezing of food, increasing output without requiring a large amount of space. Compared to mechanical freezers, which take longer to freeze products, they increase both the production and the quality with a low investment of capital.

In particular, cryogenic freezers are useful for freezing par-baked goods, which are partially baked before being frozen for storage. Par-baked items allow fast-food restaurants, supermarkets, sandwich shops, cafes, and other institutions to offer fresh, healthy baked goods without needing to bake from-scratch every day. For a commercial baking facility, investing in a cryogenic freezer is the best way to increase their output, grow their business, and become more profitable.

Cryogenic freezers work by using liquid nitrogen to quickly chill items to safe temperatures for frozen storage. As in any environment where liquid nitrogen is present, there is a danger of oxygen depletion and asphyxiation. Thus, it is always a good idea to have an O2 deficiency monitor present onsite to protect the health of employees.

One subset of cryogenic freezers, the tunnel freezer, uses a continuous freezing model of a conveyor belt, an injection system, and an exhaust system to vent gases. When the texture of the finished product is paramount, as in baked goods or seafoods, or when it's necessary to flash freeze hot foods quickly, a tunnel freezer is the best way to maintain quality in the end product.

Why an Oxygen Detector is Necessary with Cryogenic Freezers

As mentioned above, cryogenic tunnel freezers rely on an inert gas, nitrogen, to flash freeze food items. Nitrogen is perfectly safe when used in the closed-loop freezer system and properly vented from the facility. However, if the exhaust system were to develop a leak, nitrogen gas could enter the manufacturing facility and start to displace oxygen from the air. Since nitrogen is colorless and odorless, staff would not notice the leak. In a matter of minutes, ambient levels of oxygen could drop so severely that staff could become disoriented, lose consciousness, or die.

Simply by installing O2 monitors wherever nitrogen gas is used or stored, you can monitor levels of oxygen in the air and ensure there is no risk of oxygen displacement from a nitrogen leak. In the event that nitrogen leaks into the environment, the O2 deficiency monitor will sound an alarm and flash lights to let staff know that oxygen levels have fallen below the acceptable threshold set by OSHA. Staff can then evacuate before their health is compromised.

There are many styles of O2 monitors, but the one we recommend for flash freezing environments is the Sample Draw oxygen monitor. The style of O2 monitor can be placed outside the freezer and monitor levels of oxygen inside the freezer using a polyurethane tube. This ensures the sterility of the flash freezing environment while safeguarding workers. With a state-of-the-art zirconium oxide sensor, this style of oxygen detector can last without any maintenance for up to 10 years.

PureAire has over 15 years of experience, and is an industry leader in oxygen detector technology. To learn more about the Sample Draw oxygen monitor, please visit www.PureAireMonitoring.com.