Breathing Filter

Breathing filters provide protection against vapours, chemical substances and toxic gases. They usually consist of a bed of activated carbon. They are described according to 2 criteria: filter type and class. A specific filter for a given gas or family of gases or vapours is indicated through marking consisting of a letter and a strip of a certain colour. If the filter is designed to protect against several families of gas simultaneously, we call it a combined filter: it is designated by the juxtaposition of a letter and the corresponding colour strips.

AB = Filters organic gases/vapours and inorganic gases/vapours. BK = Filters inorganic vapours, ammonia and ammonia derivatives. How to select the right class of efficiency for your breathing filter. As for aerosol filters, there are three classes of protective filters based on their capacity (in other words, the best balance between volume and effectiveness of the absorbent material). Class 1: For gas concentrations of less than 0.1% by volume, the lowest capacity (filters for half masks). Class 2: For gas concentrations of between 0.1% and 0.5% by volume, medium capacity (cartridge). Class 3: For gas concentrations of between 0.5% and 1% by volume, the largest capacity (large-capacity canister worn at waist-level). At an equivalent ambient concentration level, a class 3 filter will operate for longer than either a class 2 or a class 1 filter. Some manufacturers offer specific filters that provide protection against carbon monoxide (CO). They are to be used exclusively with life-saving and evacuation devices.

A breathing filter no longer functions properly when the carbon granules become saturated. It starts to let through all the pollutants with which it is in contact. For this reason, a breathing filter needs to be replaced on a regular basis, before the filter becomes totally saturated. Particle filters are identified by their characteristics, which are printed directly on the mask. FF stands for Filtering Facepiece, while P1, P2 and P3 refer to the class of filter efficiency. On filtering cartridges, this information is shown on a white strip marked either P1, P2 or P3. The different particle filter classes: Filters at least 80% of airborne particles (means that fewer than 20% of particles pass through the filter). Offers protection against solid particles that are not specifically toxic. Filters at least 94% of airborne particles (means that fewer than 6% of particles pass through the filter). Offers protection against hazardous and irritant airborne particles in solid and/or liquid form (silica, sodium carbonate, etc.)

Filters at least 99.95% of airborne particles (means that fewer than 0.05% of particles pass through the filter). Offers protection against toxic airborne particles in solid and/or liquid form. The service life of particle filters depends on the environment. The filters become clogged over time and let less and less air through. When it becomes difficult to breathe, you will know the filter is getting to the end of its service life and needs to be replaced.

Combined filters are designed to offer protection against airborne particulate, gases and vapours simultaneously. They are made up of a particle filter combined with a breathing filter. They are characterised by dual marking: the coloured strip for breathing filters plus the white strip for particle filters. A filter with the colour code shown opposite is suitable for the following contaminants. Gas and vapours of organic compounds with a boiling point ≥ 65°C, up to the concentrations covered by a class 2 filter (5,000ppm). Inorganic gases and vapours up to the concentrations covered by a class 2 filter (5,000ppm). Particles up to the concentrations covered by a class 3 filter.

Heat and moisture exchangers and breathing breathing filter are intended to replace the normal warming, humidifying and breathing filtering functions of the upper airways when these structures are bypassed during anaesthesia and intensive care. Guidance on their use continues to evolve. The aim of this part of the review is to describe the principles of their action and efficiency and to summarise the findings from clinical and laboratory studies. Based on previous studies, an appropriate minimum target for moisture output is 30 and 20g.m−3 for long-duration use in intensive care and short-duration use in anaesthesia, respectively. The practice of reusing a breathing system in anaesthesia, provided it is protected by a breathing filter, assumes that the breathing filter is effective. However, there is wide variation in the gas-borne filtration performance, and contaminated condensate can potentially pass through some breathing filters under typical pressures encountered during mechanical ventilation.

When a patient’ s trachea is intubated or a supraglottic airway device is placed in situ, the normal warming, humidifying and breathing filtering functions of the upper airways are bypassed. Hence, gas delivered to the patient needs to be artificially conditioned to replace these lost functions. Heat and moisture exchangers (HMEs) are intended to conserve a portion of the patient’ s exhaled heat and moisture, and condition inspired gas by warming and humidifying it. breathing breathing filter are intended to reduce the transmission of microbes and other particulate matter in breathing systems. Devices that contain both a breathing filter and an HME are termed heat- and moisture-exchanging breathing filters (HMEFs). The terms ‘electrostatic’ and ‘pleated’ used to distinguish the two common types of breathing filter are not ideal, as both types rely to some extent on electrostatic charge to hold particles within the breathing filter material and both types of material could be pleated. The main difference between the two types is the density of the fibres. For ‘electrostatic’ breathing filter material, the density of fibres is comparatively low and the electrostatic charge on the fibres is high. For ‘pleated’ breathing filters, the density of the fibres is high: this causes an increase in the resistance to gas flow; pleating the material increases the surface area and thus reduces resistance. This type of breathing filter is also termed ‘hydrophobic’ (as the surface of the breathing filter material repels water) or ‘mechanical’. For this review, the terms ‘electrostatic’ and ‘pleated’ will be used to distinguish the two types of breathing filter.

HangZhou Trifanz Medical Device Co., Ltd is located in the vibrant bio-industrial park of LinPing, Hangzhou. The park enjoys a beautiful environment and convenient transportation. It is adjacent to Shanghai, Ningbo and other important ports. The company is an integrated science and technology innovation enterprise, mainly engaged in the research, development, production and sales of medical catheters in the fields of respiration, anesthesia, and severe diseases. It has its own R&D team: a group of professional and technical personnel with nearly 20 years of experience in the industry; own The production site: 1000 square 100,000 GMP clean workshops; among the company's employees, more than 80% of college and university staff account for the company's production and operation activities in strict accordance with national and international requirements to run the quality management system cloud operation, passed the CE, ISO13485 system certification; can provide OEM / ODM services.