New requirements for safe use and storage of liquid nitrogen and dry ice

The College of American Pathologists ("CAP")recently imposed new requirementsto address risks related to the use and storage of liquid nitrogen ("LN2") and dry ice.

Background

The new requirements come after a deadly incident in 2017, when liquid nitrogen leaked at a Georgia lab that was not accredited through CAP.  Emergency responders were called to the scene when an employee suffered burns and, moreover,lost consciousness from oxygen deprivation caused by the leak. While the employeeeventuallyrecovered from her injuries, one of the first responders died of asphyxiation as a result ofthe nitrogen leak.

That unfortunate incident illustrates the dangers of nitrogen leaks,which are inherent in the storage and use of LN2. Indeed, there are several cases reported nearly every year of laboratory personnel who die of asphyxiation caused by exposure to nitrogen gas.
Asphyxiation riskis present in dry ice usage as well since, if it is stored in areas without proper ventilation, dry ice can replaceoxygen with carbon dioxide, potentially causing workers to rapidly lose consciousness.

CAP’s New Regulations

Despite their safety risks, both dry ice and LN2 have many beneficial uses in commercial and lab settings, including hospital and research facilities. As such, CAP’s new focus on utilizing best practices to increase employee safety and reduce the danger of nitrogen leaks is vitally important.
Before the regulations were changed, lab directors had greater personal discretion in selectingthe types and deployment of safety equipment utilized in their facilities. Now, laboratories are required to place oxygen("O2") monitors at human height breathing levels anywhere liquid nitrogen is used or stored, and they must place signage warning of safety risk regarding, and train all affected employees on safe handling of, LN2 and dry ice.

Pathologists understand that oxygen/carbon dioxide monitors must be placed appropriately anywheredry ice or LN2 are used or stored.  Even a couple tanks of liquid nitrogen kept in a supply closet pose a safety risk, because even a small leak can quickly displace a large amount of oxygen.

Oxygen Monitors Protect Laboratory Workers

While many people realize that the use and storage of liquid nitrogen and dry ice can present health risks, they may fail to grasp the speed at which circumstances can become dangerous.  It takes only a few breaths of oxygen-deficient air for one to lose consciousness.

AS CAP recognized, oxygen and carbon dioxide monitors offer an effective solution to the health and safety risks posed by nitrogen leaks and inadequatedry ice storage. O2/CO2 monitors continually monitor the air, and they will remain silent so long as oxygen and carbon dioxideremain within normal levels.However,in the event that oxygen is depleted to an unsafe level (19.5%, as established by OSHA), or carbon dioxide levels rise to an unsafe level, alarms embedded in the monitors will sound, alerting employees to evacuate the area and summon assistance from qualified responders.

PureAireMonitors

PureAire Monitoring Systems’ line of oxygen and dual oxygen/carbon dioxide monitors offerthorough air  monitoring, with no time-consuming maintenance or calibration required., The monitors function well in confined spaces, such as closets, basements, and other cramped quarters.  PureAire’s monitors can handle temperatures as low as -40 C, making them ideally suited for environments, such as laboratories, that utilize liquid nitrogen or dry ice. A screen displays current oxygen levels for at-a-glance reading by employees, who derive peace of mind from the monitor’s presence and reliable performance.
Built with zirconium oxide sensor cells and non-dispersive infrared sensor (NDIR)cells, to ensure longevity, Pure Aire O2 monitors can last, trouble-free, for over 10 years under normal operating conditions.  That makes PureAire a cost-effective choice forprotecting employees and complying with the new safety regulations affecting labs and hospitals.
Learn more about oxygen monitors and best practices for their use at www.pureairemonitoring.com.

From Farm to Market: Fruit Ripening

Fruit has a brief window where it is perfectly ripe. If farmers waited until every piece of fruit was ripe before harvesting, farming would be more labor-intensive as farmers rushed to pick ripe fruits. Prices might crash due to a short-term glut of fruit on the market. To ensure a steady supply and demand, keep prices competitive, and reduce food waste, farmers use artificial ripening procedures. One method for ripening fruit after harvest involves ripening chambers. Ripening chambers using ethylene, a natural plant hormone, enable the fruit to be harvested, stored, and transported to where it will be marketed and consumed. While ethylene ripening chambers are beneficial, they are not without risks.

How Ethylene Ripening Chambers Work

While there are other ways to artificially ripen fruit in ripening chambers, ethylene has become a favorite, since it occurs naturally in fruit.
Ethylene is a natural hormone found in plants. Fruits begin to ripen when exposed to ethylene, whether the exposure occurs naturally or artificially. In ethylene ripening chambers, unripe fruits are laid out, and the chamber is sealed.Ethylene gas is then piped into the sealed chamber. As the fruit is exposed to ethylene, the fruit
“respires”,which involves intake of oxygen andemission of carbon dioxide. For the ripened fruit to have the right color and flavor, the ripening should occur in a controlled atmosphere in which the temperature, humidity, ethylene, oxygen, and CO2 concentrationaremaintained at optimum levels.
However, there is a risk of combustion from the ethylene gas, as well as decreased levels of oxygen and increased levels of carbon dioxide inside the chamber.

How Oxygen/Carbon Dioxide and LEL Combustible Monitors Protect Employees

Low oxygen levels cause respiratory distress. If oxygen levels drop below the safe threshold for breathing, which could happen in the event of an ethylene gas leak, employees could suffocate. Suffocation is also a danger when there is too much carbon dioxide in the air. Ethylene gas used in ripening chambers would be hazardous if an employee were to enter the chamber before determining that oxygen and carbon dioxide were at safe levels.

A dual oxygen/carbon dioxide (O2/CO2) monitor detects the levels of oxygen and carbon dioxide within the chamber and sounds an alarm should the oxygen level falls to an OSHA action levelor if the carbon dioxide rises to an unsafe level.  By checking the monitor’s display, an employee will know when it is safe to enter the chamber.

PureAire Monitoring Systems has developed its dual O2/CO2 monitor with zirconium oxide and non-dispersive infrared sensor (“NDIR”) cells. The cells are unaffected by changing barometric pressure, storms, temperatures, and humidity, ensuring reliable performance.  Once installed, the dual O2/CO2 monitor needs no maintenance or calibration.

Ethylene is a highly flammable and combustible gas. If the gas lines used to pipe ethylene into the ripening chambers were to develop a leak, the chamber could fill with ethylene and reach combustible levels. A combustible gas monitor, which takes continuous readings of combustible gases, would warn employees of an ethylene leak within the chamber.

PureAire Monitoring System's Air Check LEL combustible gas monitor continuously monitors for failed sensor cell and communication line breaks. The Air Check LEL gas monitor is housed in an explosion-proof enclosure. If a leak or system error should occur, an alarm will immediately alert employees.

To learn about PureAire Monitoring Systems’ dual O2/CO2 monitors or the Air Check LEL Combustible monitor, please visit www.pureairemonitoring.com.

IVF Cryopreservation and Safe Handling Practices

Couples that want to have a baby but have not been able to conceive naturally are drawn to invitro fertilization (IVF) treatments.

In an IVF treatment, several eggs are fertilized at once, which creates multiple embryos. While more than one embryo may be implanted, to spur the odds of pregnancy, there are inevitably some unused embryos.

The remaining embryos may be preserved cryogenically, for use later, rather than destroyed. There are many reasons couples may select cryopreservation of embryos, including:

• A second chance if the IVF treatment fails the first time around
• The desire to have another child
• As a precaution before undergoing medically necessary procedures that might the reduce the odds of a successful pregnancy, such as cancer treatment
• Opportunity to use embryos in medical research
• Opportunity to donate embryos to another couple

The National Embryo Donation Center estimates that there are over 700,000 human embryos currently stored in the United States.

The cryogenic process relies on cryoprotective agents (or CPAs), which protect the embryo from damage while it freezes. Damage may occur as ice crystals form during the freezing process. Without the use of CPAs, the ice crystals could pierce the embryo wall, causing embryo failure.

Cryopreservation facilities may use either a slow or fast method to freeze the embryos. In the slow method, embryos are frozen in stages, with protective agents added in slow doses over time. The frozen embryos are then preserved in liquid nitrogen until they are slowly thawed for use.

The fast-freezing method combines higher concentrations of CPAs to the embryo, after which the embryo is quickly plunged into liquid nitrogen. The process is so quick that ice is unable to form, thus protecting the embryo from damage.

Wherever liquid nitrogen is used, there are risks associated with nitrogen leaks. Nitrogen displaces oxygen, and a leak would rob the air of oxygen, thereby creating a health hazard for medical staff. When there is not enough oxygen in the air, persons working in the area can suffocate due to the lack of oxygen. Since nitrogen lacks color and odor, there is no way to detect a leak using the senses. In addition, a nitrogen leak could lead to failure of the cryopreservation tanks storing the embryos. In order to ensure the safety of employees, and the viability of the embryos, cryopreservation facilities need to rely on oxygen monitors.

How Oxygen Monitors Protect Employee Health in IVF Facilities

Oxygen monitors continually sample the air, taking periodic readings of current oxygen levels. In the event of a nitrogen leak, and a drop in oxygen to an OSHA action level, the built-in horn will sound, and lights will begin to flash, thereby providing notification to the employees that they must exit the area.

Best practice calls for oxygen monitors to be placed wherever nitrogen is used or stored. Not all oxygen monitors currently on the market are suitable for use in confined spaces or in freezers.

PureAire Monitoring Systems oxygen monitors are uniquely suited for use in an IVF facility, because the monitors can withstand temperatures as low as -40C.

PureAire Monitoring Systems monitors feature long-lasting zirconium sensors, which are designed to provide accurate readings, without calibration, for up to 10 years. Busy IVF facilities will appreciate the ease of use, and low maintenance of PureAire Monitoring Systems products.

To learn more or to view product specs, please visit www.pureairemonitoring.com