Respirator
As a respirator all devices are referred to generally used for respiratory protection. They offer protection from substances, particles or organisms that can enter the body via the respiratory tract.
In principle, breathing apparatus can be divided into two groups. In Europe these definitions can be found in EN 133
- Ambient air-dependent respiratory protection : Breathing connection and respiratory protection filter - also known as filter devices , in fire services, ambient air-dependent respiratory protection
- Ambient air-independent respiratory protection: Breathing connection with a device for the supply of non-contaminated breathing gas - also known as isolating devices, in fire services, self-contained breathing apparatus .
Respiratory protection devices are used in industry as well as in various aid organizations such as the fire brigade or rescue service.
Fire director Erich Giersberg is considered the inventor of the breathing apparatus .
Ambient air-dependent respiratory protection
- Before using filter devices, it must be ensured that at least 17% by volume of oxygen (with CO filters at least 19% by volume of oxygen) is present in the air and the substances to be filtered are known; Otherwise, self-contained breathing apparatus must always be used. The application limits of the filter devices are determined by the performance of the filters . The substances or substance areas for which the individual filters are suitable are indicated by color coding and letters on the filters. A maximum capacity of the filters is also specified. Since a negative pressure is created in the respirator when inhaling , pollutants can get into the airways through possible leaks . Therefore, a leak test is carried out after putting on the respirator.
In medical work areas, mouth and nose protection , which is not part of the respiratory protection equipment, is used to protect against infections . The protective effect of these simple half masks is limited. Studies at the Institute for Occupational Safety and Health of the German Social Accident Insurance have shown that the wearer of a particle-filtering half mask is significantly better protected.
Filter devices
A filter device consists of a breathing connection (e.g. a respirator ) and one or more filters . The filter devices were formerly also known as gas masks .
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Filters can be divided into:
- Gas filter that removes gases from the air as an adsorption filter (usually activated carbon ) or catalytic filter (for carbon monoxide )
- Combination filter that removes both gaseous components and (solid and / or liquid) aerosol particles from the air you breathe
- Particle filter that removes solid and / or liquid aerosol particles from the air we breathe, e.g. B. Asbestos , smoke , fog
When it comes to filters, it should be noted that most filters, especially gas filters, only have a limited service life. After removing the seals, a filter can only be used for a maximum of six months as long as it has not come into contact with harmful substances. However, it continuously loses its capacity during this period, which is why keeping a filter book is highly recommended, as well as regular checks and, if necessary, the replacement of unused filters .
Ambient air-independent respiratory protection
Ambient air-independent breathing protection is understood to mean devices which isolate the wearer of breathing apparatus from the ambient atmosphere and supply them with breathable gas from a non-contaminated source. These devices are therefore also referred to as isolation devices and consist of a breathing connection and an air supply device.
Isolation devices can be divided into:
- freely portable
- Container devices
- Regeneration devices
- not freely portable
- Compressed air hose devices
- Fresh air hose devices
use
If the ambient air contains too little oxygen , less than 17% by volume, or if there are toxic gases that cannot be absorbed by gas or combination filters and if the type and / or concentration of the respiratory toxins is unknown, self-contained breathing apparatus must be used.
Mostly freely portable isolation devices z. B. SCBA used. Due to the limited amount of air, however, the operating time is usually limited to 15–30 minutes. The duration of use depends on the age of the person wearing the respirator, the physical performance and the type of stress involved. If a longer period of use of sometimes several hours is required (e.g. in mining or in tunnels), so-called long-term devices (e.g. with 2 CFRP bottles with a volume of 6.8 l and a filling pressure of 300 bar), regeneration devices or rebreather devices are used.
Since it is difficult to determine whether there is really enough oxygen in the ambient air during use by the fire brigade and since the composition of the air can change very quickly and significantly in the event of fires or escaping gases, self-contained breathing apparatus is mainly used.
Freely portable isolation devices
Container devices (BG)
With this type of device, the wearer of breathing apparatus carries the necessary breathing air with them in compressed air cylinders , which is why they are also known as compressed air breathing apparatus (PA).
It should be noted that the compressed air is specially cleaned and de-oiled breathing air in accordance with DIN EN 12021 and the containers are therefore referred to as breathing air bottles .
construction
The usual respiratory protection devices have cylinders in which the air is stored at 200 or - more frequently for some years - 300 bar . The bottles can be made of steel , rarely of aluminum, of a metal-fiber plastic composite with glass fiber (GRP), Kevlar or of carbon fiber (CFRP). For several years, "Class 4 composite" bottles have been on the market in which only a neck piece with the thread for screwing in the valve is made of metal. The largely gas-tight, thin liner can be made of PET thermoplastic and wrapped in epoxy resin with carbon fiber .
The air under dangerous high pressure (HP) is made breathable through a typical 2-stage pressure reduction in the regulator . A first pressure reducer , usually screwed directly onto the cylinder valve , reduces the supply pressure from (maximum) 200 or 300 bar to the so-called medium pressure (MD) of - depending on the device type - 4 to 12 bar. On the respirator itself there is the regulator in the narrow sense, which can be understood as a second, very finely working pressure regulator or a metering device. Here, the low pressure is reduced to a low pressure that can be breathed by humans (in the millibar range) and only the amount of air required by inhaling - and thus generating a slight drop in pressure - is released.
Normal-pressure regulators release the air volume particularly sparingly, whereas those in positive-pressure design put the respirator under a certain low pressure in order to prevent pollutants from entering the mask from outside.
(Regulators for diving or for respiratory physiological examinations work in principle in the same way. However, divers generally need ballast, which is why heavy, robust, galvanized steel cylinders are used here.)
With 200 bar devices , two bottles with a capacity of 4 liters each are common. In purely mathematical terms, this results in 1600 liters of normal air and an operating time of around half an hour .
300 bar devices normally have a steel compressed air cylinder with a volume of 6 liters (1,636 l breathing air) or one or two composite cylinders (CFRP) each. 6.8 liters volume (1,854 or 3,708 l breathing air). At 300 bar a bottle stores only - rule of thumb - the 270fache of the bottle volume of air norm volume because air bar already evident in more than 200 non-ideal behavior.
( Boyle-Mariotte's law , which is easy to use for a rough estimate , according to which the product of pressure and volume is constant, strictly applies only to an ideal gas and only to isothermal changes in state . In reality, however, no gas behaves ideally, and thus also not In addition, the filling process of the bottle is not isothermal, which can even be felt with the hand. The calculations therefore lead to inaccurate results. More precise equations of state, for example the Van der Waals equation , allow more precise results.)
Long-term compressed air breathing apparatus have two 300 bar cylinders and are usually made of a composite material, especially CFRP, for weight reasons. Please note that compressed air breathing apparatus must not exceed a total weight of 18 kg.
The bottles are attached to a carrier frame, which is padded or bowl-shaped for better carrying. The shoulder straps and the waist belt are adjustable and must be tight when carried. They are flame-retardant and made from rot-proof material.
In the case of breathing apparatus, the cylinder valves are usually arranged at the bottom, so that they are not a hindrance when climbing under collapsed ceiling joists and are protected from being hit. In diving equipment, the valves are usually oriented upwards, because there is more of a risk that a device will hit the curb when jumping off a boat; moreover, a second regulator allows a second diver to be saved better if his hose is from the shoulder area and does not come off the hip area.
Pressure control
To check you have a pressure gauge (also pressure gauge ), following which one can constantly how high the air pressure in the bottle yet. There is a warning device to prevent the bottle from running out of air. The most widespread is the acoustic warning device in the form of a signal whistle, which starts to whistle at a pressure between 50 and 60 bar (in Austria 55 ± 5, with older devices between 60 and 68 bar). Other newer device types use a warning device integrated in the regulator that does not use any air for the warning signal. In addition, the warning is more immediate and there is less risk of confusion. The warning signal is not a withdrawal signal, as, depending on the local conditions, the way back can take longer than the air left. The respiratory protection monitoring to be carried out , regular pressure control and the calculation of the retreat path (twice the approach path) are also important. The retreat is started in groups and depends on the wearer of breathing apparatus with the greatest consumption of breathing air (see operational principles of FwDV 7 breathing protection).
With older devices, which today no longer meet the standard, there was a so-called resistance warning . When the pressure dropped to 40–50 bar, the breathing resistance increased and you had to flip a lever directly on the device in order to be able to breathe normally again. Since some carriers easily panicked, this species is no longer commonly used.
Safety measures
Another new safety measure, especially with self-contained breathing apparatus, is the so-called dead man's alarm or motionless detector . The dead man's alarm is a small electrical device about the size of a cigarette packet. It reacts if there is no more movement within a certain time interval. Then a pre-alarm sounds first, followed by a louder acoustic and an optical signal. If a squad is in danger and urgently needs help, an emergency call button can also be pressed, which immediately activates the said alarm. This is why the device is officially known as the "emergency signal generator". The alarm can be deactivated manually at any time. The dead man's alarm is not yet a standardized device, but it is still used by many fire services. It is advisable to use it, although it is quite expensive to buy and maintain.
Instructions for use
Before wearing respiratory protective equipment, alcohol is strictly forbidden , even with colds or hay fever you should not use rebreather devices. The additional breathing resistance, in addition to the actual work, puts a heavy strain on the body. If you are not fully fit, you may feel faint or even pass out. Before putting it on, the wearer of breathing apparatus must check the device (visual inspection and brief inspection). The latter is done by first opening the cylinder valve and observing on the manometer whether the cylinder has enough pressure. The cylinder pressure must not deviate from the nominal filling pressure by more than 10%, i.e. between 180 and 220 bar for 200 bar cylinders and 270 and 330 bar for 300 bar cylinders. Then the cylinder valve is closed again. Now the pressure drop must not exceed 10 bar in one minute. The air remaining in the medium pressure range is then slowly released via the regulator until the warning signal sounds at a pressure between 60 and 50 bar. So the warning device is checked. If the device has two bottles, this must be done separately for each bottle. Now the cylinder valve is opened completely and the breathing apparatus can be put on ready for use.
Although the breathing resistance is lower than with a respiratory protection filter , the wearer must still be physically fit and healthy, otherwise circulation problems and dizziness can easily occur. Furthermore, the protective clothing of the fire brigade ensures a build-up of heat because the body heat is not dissipated through the protective clothing. Therefore, the wearer of breathing apparatus should drink enough fluids before using the breathing apparatus.
In Germany, the occupational medical check-up after the preventive medical check-up is G 26.3 for wearers of self-contained, heavy breathing protection, G 26.2 for wearers of medium, self-contained and self-contained breathing protection and G 26.1 for wearers of light, self-contained breathing protection aged 18 to 49 years The examination is carried out every 3 years at the latest and annually from the age of 50.
In Austria, wearers of breathing apparatus in the fire service must be at least 18 years old and have been a member of a fire service for at least one year. The fitness check is also carried out every 3 years between the ages of 18 and 50 years. If you are over 50 years of age, the examinations must be carried out annually. The prerequisite for wearing respiratory protective equipment is the completion of the corresponding courses at the (state) fire brigade schools or the corresponding training outside of the schools.
Regeneration devices
Regeneration devices, also known as rebreather devices, are also breathing apparatus for self-contained breathing apparatus.
construction
In contrast to the container devices, they do not provide all of the air to be inhaled, but have a built-in oxygen source. These sources can be oxygen bottles, liquid oxygen, or chemically bound oxygen. The exhaled carbon dioxide is chemically bound in a carbon dioxide filter and the oxygen consumed is replenished from the bottle.
The devices are much more maintenance-intensive than the compressed air devices commonly used in fire services. Upgrading the devices requires time-consuming tests and is therefore only very rarely done at locations that stretch over a long period of time, often with the aid of " roll-off containers for breathing protection".
application
Before wearing respiratory protective equipment, alcohol is strictly forbidden , even with colds or hay fever you should not use rebreather devices. The additional breathing resistance, in addition to the actual work, puts a heavy strain on the body. Those who are not fully fit can easily get weak or even pass out.
The advantage of rebreather devices is the longer technical duration of use (up to 4 hours), since only a "small" portion of the required breathing air has to be carried in compressed form. The duration of use is limited by the wearer's exhaustion rather than the device.
A disadvantage besides those already mentioned is that the breathing air heats up over time due to the chemical reaction that binds the exhaled carbon dioxide. Therefore, in the past, those who wear these breathing apparatus often developed pneumonia when they took off. Modern devices try to compensate for this with cooling systems, but these increase the weight of the device.
Because of these disadvantages, they are mostly only used by fire brigades where longer service lives are to be expected, such as in tunnels and in mining .
Not freely portable insulating devices
Hose devices
In the case of hose devices, the breathing air is not taken from containers carried along, but fed to the regulator via a hose connection (usually medium pressure, approx. 5 bar) from an external source. The advantage of such a system lies in the elimination of the restrictions on the duration of use and the reduction in the weight to be carried by the user. Disadvantages are the restriction of freedom of movement and the vulnerability of the hose connection. For these reasons, breathing apparatus are generally from fire or mine rescue teams do not , or only at empty air cylinders at the " decontamination space used". But you are z. B. to be found in commercial workplaces with high concentrations of pollutants and low other risks.
Exemplary areas of application for breathing apparatus
- Industry and craft
- Garbage treatment
- Chemical and pharmaceutical industry
- Woodworking
- paint shop
- Mining
- Rescue services (fire brigade, technical relief organization and aid organizations)
- Fires
- Accidents involving dangerous goods
- Medical section
- Reduction of germs in the exhaled air of the practitioner (e.g. during operations)
- Transport or treatment of patients with infectious diseases (e.g. MRSA , tuberculosis )
Standards, guidelines, regulations
DIN standards
- DIN 58600 respiratory protection devices - plug connection between the regulator for compressed air breathing apparatus in positive pressure version and the breathing connection for the German fire services
European standards
- EN 132 Respiratory protective devices - Definitions of terms and pictograms
- EN 133 Respiratory Protective Equipment - Introduction
- EN 134 Respiratory protective devices - naming of individual parts
- EN 135 Respiratory protective devices - List of synonymous terms
- EN 136 Respiratory protective devices - full face masks
- EN 137 Respiratory protection devices - container devices with compressed air (compressed air breathing apparatus)
- EN 138 Respiratory protective devices - Fresh air hose devices in connection with full face masks, half masks or mouthpiece fittings
- EN 140 respiratory protective devices - half masks and quarter masks
- EN 142 Respiratory protection equipment - mouthpiece sets
- EN 143 Respiratory protective devices - Particulate filters
- EN 144 Respiratory Protective Equipment - Gas Bottle Valves
- EN 145 Respiratory protective devices - Regeneration devices with pressurized oxygen or pressurized oxygen / nitrogen
- EN 148-1 Respiratory protective devices - Threads for breathing connections Part 1 - Round thread connection
- EN 148-2 Respiratory protective devices - Threads for breathing connections Part 2 - Central thread connection
- EN 148-3 Respiratory protective devices - Thread for breathing connections Part 3 - Thread connection M 45 × 3
- EN 12941 Respiratory protective devices - Powered air filter devices with a helmet or a hood
- EN 12942 Respiratory protective devices - Blower filter devices with full face masks, half masks or quarter masks
- EN 14387 Respiratory protective devices - gas filters and combination filters
- EN 14593-1 Respiratory protective devices - Compressed air breathing apparatus with regulators - Part 1: Devices with a full face mask
- EN 14593-2 Respiratory protective devices - Compressed air breathing apparatus with regulators - Part 2: Devices with a half mask and positive pressure
- EN 14594 Respiratory protective devices - Compressed air breathing apparatus with continuous air flow
Guidelines
- EU Directive 89/686 / EGW of the Council of December 21, 1989 on the harmonization of the legal provisions of the member states for personal protective equipment
German regulations
- BGR / GUV-R 190 - Use of breathing apparatus (not valid in the mining and fire brigade areas)
- Fire service regulation 7 - respiratory protection (also with adaptations for the technical relief organization in circulation)
Testing and certification of respiratory protective devices
Respiratory protection devices belong to the personal protective equipment (PPE). These must be certified by a notified body in the European internal market . Testing and "certification" (issuing of an EU type examination certificate) serve as evidence of compliance with the basic health and safety requirements according to Annex II of Regulation 2016/425 of the European Parliament and Council (PPE Regulation).
Respiratory protective devices are assigned to category III (risks that can lead to very serious consequences such as death or irreversible damage to health). They are therefore subject to an EU type test and the inspection of the PPE according to Module C2 or Module D of the PPE Regulation.
The issue of an EU-type examination certificate is part of the conformity assessment procedure. If the manufacturer fulfills all the requirements of the relevant European legislation, he declares this in the EU declaration of conformity. He marks the PPE with the CE mark ; in the case of respiratory protection, the CE mark is followed by the identification number of the notified body that is active in the process according to the PPE regulation Annex VII or VIII.
The EU type examination and the control of the PPE may only be carried out by bodies that have been designated (notified) for a defined product area by the responsible national authorities of the EU Commission .
Directive 89/686 / EEC, which has been in force since July 1992, is repealed with effect from April 21, 2018. It is replaced by the PPE regulation cited above. However, this does not change the classification of breathing apparatus in Category III.
Differentiation between respiratory protection and medical face masks
In the health sector , mouth and nose protection products (MNS) are used to protect the person being treated against infectious germs . The properties of these masks are described in the European standard EN 14683 "Medical face masks - requirements and test methods". Masks that meet these requirements can be placed on the market as non-invasive medical devices in accordance with EU Directive 93/42 / EEC . Use as personal protective equipment (PPE) is not intended.
Products can simultaneously meet the requirements of the EU Medical Directive and the EU PPE Regulation. An investigation of 16 products with standardized tests according to the requirements for respiratory protective devices has shown that three of these products met the requirements for both leakage and filter permeability according to the respiratory protection standard EN 149 . All other requirements of EN 149 were not taken into account. With high-performance filter material, the missed leakage is particularly important as a contribution to the overall leakage. The missed leakage is caused by a poor sealing fit.
In principle, the MNS is not intended and suitable as PPE, because it primarily protects the person being treated, while PPE protects the wearer. Nevertheless, a certain degree of self-protection is achieved with MNS, as it prevents contact with contaminated hands in the mouth and nose area. Information on special medical or biological situations and the use of respiratory protection is available from the Committee for Biological Agents (ABAS) and the Federal Institute for Occupational Safety and Health (BAuA).
history
The French Jean-François Pilâtre de Rozier did pioneering work in the field of respiratory protection when he presented the construction of the first suction hose respiratory protection device as early as 1785. The equipment wearer breathed in the air from a portable leather sack through a hose with a mouthpiece. However, the useful life was short and the application was intended more for mining.
See also
- Respiratory protection pillow
- Respiratory protection compressor
- Respiratory protection accident
- Entry-level device
- Incorporation (medicine)
- Rebreather
literature
- Lothar Brauer: Manual respiratory protection . Ecomed Verlag (loose-leaf publication).
- Stefan Dreller u. a .: On the question of suitable respiratory protection against airborne infectious agents . In: Hazardous substances - keeping the air clean , Volume 66, No. 1/2, 2006, pp. 14–24.
- Karl-Heinz Knorr: Die Roten Hefte, Heft 15 - Respiratory protection . 14th, revised edition. Kohlhammer, Stuttgart 2008, ISBN 978-3-17-020379-2 .
Web links
Individual evidence
- ↑ Respiratory protection performance test (PDF; 2.2 MB) of the Styrian Fire Brigade Association from April 1, 2007, accessed on December 13, 2010.
- ↑ Respiratory protection performance test (PDF;) of the Styrian Fire Brigade Association from April 1, 2017, accessed on January 6, 2018.
- ↑ DGUV rule 112-190 (PDF) accessed on October 3, 2013.
- ↑ Fire Brigade Service Regulations 7 (FwDV 7) (PDF), accessed on October 3, 2013.
- ↑ Fire service regulation 7 (FwDV 7) with adjustments for the technical relief organization ( Memento from October 4, 2013 in the Internet Archive ) (PDF; 363 kB), accessed on October 3, 2013.
- ↑ a b Regulation (EU) 2016/425 of the European Parliament and of the Council of March 9, 2016 on personal protective equipment and repealing Directive 89/686 / EEC of the Council , accessed on May 9, 2018
- ^ Nando (New Approach Notified and Designated Organizations) Information System. Retrieved May 9, 2018 .
- ↑ Does medical (operating theater) mouth and nose protection also protect the practitioner? (PDF) Retrieved May 9, 2018 .
- ↑ Infection prevention in the care and treatment of patients with communicable diseases. Bundesgesundheitsblatt 2015, 58: 1151–1170 DOI 10.1007 / s00103-015-2234-2 ; accessed on March 5, 2019
- ↑ Resolution 609 Occupational Health and Safety in the event of an inadequately vaccine-preventable human influenza. Retrieved May 9, 2018 .
- ↑ TRBA 130: Occupational safety measures in acute biological hazard situations. (PDF) Retrieved May 9, 2018 .
- ^ Franz-Josef Sehr : Development of fire protection . In: Freiwillige Feuerwehr Obertiefenbach e. V. (Ed.): 125 years of the Obertiefenbach volunteer fire brigade . Reference 2005, ISBN 978-3-926262-03-5 , pp. 114-119 .