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1. Is the BioPak 240R a positive-pressure, pressure-demand device?
2. What is “Solid-Core” CO2 scrubber technology?
3. What is Tidal Volume and why is this important?
4. What are the materials of the exposed components of the BioPak?
5. When was the design and certification of the BioPak 240R completed?
6. Are there modern 4-hour rebreathers other than the BioPak 240R available in the market today?
7. What are the differences between the standard and fire-rated harnesses of the BioPak 240R?
8. Where is the breathing bag located in the BioPak?
9. Does the BioPak have an exposed breathing bag?

Is the BioPak 240R a positive-pressure, pressure-demand device?
The BioPak 240R is a positive-pressure, pressure-demand, constant-demand device. What do these terms imply?
Positive-Pressure: The BioPak 240R has been certified to provide positive breathing pressure to the user for EN145 breathing rates of 30, 50 and 75 liters per minute; and, NIOSH breathing rates of 40 liters per minute. Positive pressure refers to the pressure within the breathing loop of the BioPak being higher than the atmospheric pressure outside of the breathing loop.
Pressure-Demand: Pressure demand implies that the BioPak will deliver additional oxygen into the breathing rate based upon internal pressure of the BioPak breathing loop. A better nomenclature for this term would be “volume-demand”. The BioPak will always keep a positive pressure in the breathing loop and does not actually measure the internal pressure during operation. Demand adds are provided by the BioPak when the user consumes more oxygen than what is being supplied by the constant add. This results in a lower volume in the breathing chamber that is compensated for by the diaphragm. When the volume decreases enough, the diaphragm will actuate the demand add valve to add oxygen into the breathing loop. This system is therefore totally self-regulating to the exact needs of the user.
Constant-Demand: The BioPak will deliver a stream of oxygen into the breathing loop throughout the duration of use. This flow of oxygen is intended to furnish enough oxygen to support a user at a moderate work rate such as strenuous walking. The flow is controlled by a flow restrictor within the delivery system and is not altered based upon the needs of the user. If the user oxygen consumption exceeds the rate of the constant add then the demand add will be activated. If the user oxygen consumption is lower than the constant add then resultant excess volume is vented out of the breathing loop.

What is “Solid-Core” CO2 scrubber technology?
“Solid-Core” scrubber technology refers to the design of the CO2 absorbent itself. With Solid-Core technology there is no need for the user to measure or fill a scrubber canister with granular absorbent. A Solid-Core scrubber will not use any container that requires user filling and will also offer the further advantages of non-dusting, non-settling and non-channeling over granular absorbents. Solid-Core technology will also not increase breathing resistance as the media becomes wet as is the case with granular media. Solid-Core absorbents are supplied to the user in single use packaging to eliminate human errors in filling. The BioPak is the ONLY respirator available with Solid-Core scrubber technology.

What is Tidal Volume and why is this important?
Tidal volume is defined as the volume of gas that can be stored within the breathing loop for user consumption at any one time. The larger the tidal volume the greater the benefit to the user for several reasons. A large tidal volume will provide more breathable air than the user can inhale in one breath thus reducing situations of low inhalation pressure or a feeling of “oxygen starvation” as well as reducing demand oxygen additions resulting in oxygen conservation. Additionally, a large tidal volume will also be able to accept a larger exhalation gas volume from the user thus limiting the number of vent situations from the breathing loop and conserving breathable air. Thus a large tidal volume will provide benefits of improved breathing resistance and oxygen conservation to the user.

What are the materials of the exposed components of the BioPak?
All external components of the BioPak are constructed from flame-rated materials. Additionally, the external housing components of the BioPak are constructed from materials that are static dissipative to avoid the generation of static sparks that may lead to fire in hazardous atmospheres.

When was the design and certification of the BioPak 240R completed?
The design of the BioPak 240R was conducted based upon desired features of operation determined from an extensive user survey conducted in March of 2004. Actual design effort and in-house testing was completed by Biomarine in March of 2006. EN145 certification was granted in March of 2007, Chinese MA certification was granted in February of 2007 and NIOSH/MSHA certification was granted in June of 2007.

Are there modern 4-hour rebreathers other than the BioPak 240R available in the market today?
To the best of Biomarine’s knowledge, the BioPak 240R is the most modern, most sophisticated, most user-friendly rebreather design presently available. The BioPak 240R also provides the user with the lowest cost of ownership of all certified 4-hour rebreathers presently available.

What are the differences between the standard and fire-rated harnesses of the BioPak 240R?
The standard harness is constructed of nylon webbing, nylon straps and Acetal buckles; and, the standard harness will not stand up to direct open flames or high radiant heat due to the properties of the materials of construction. The fire-rated harness is constructed of Nomex ® and Kevlar ® webbing and straps with metal buckles and will withstand exposure to direct open flames and high radiant heat. The fire-rated harness also provides additional features of color-coded strap identification, increased adjustment features and better comfort as compared to the standard harness. Finally, due to the materials of construction, the fire-rated harness will also be of superior strength as compared to the standard harness.

Where is the breathing bag located in the BioPak?
The BioPak is designed with no breathing bag. Instead the BioPak is designed with a breathing chamber that contains a flexible diaphragm. This design provides a distinct advantage over a breathing bag design as it will provide shielding against penetration of the soft rubber diaphragm even with the upper housing not installed. A breathing bag design will be totally exposed to penetration hazards should the housing of the respirator become dislodged or breached.

Does the BioPak have an exposed breathing bag?
No. The BioPak utilizes a flexible diaphragm housed within an injection-molded housing to provide a robust breathing chamber that is resistant to externally induced damage and punctures. Other breathing respirators employ the use of a breathing bag that is suspended within the housing of the respirator itself. Should the respirator housing become dislodged the breathing bag will be totally exposed to externally generated dangers and hazards.