Este mensaje fue modificado por última vez en: 05-08-2021, 01:16 AM por henof5aqwe.

What are face masks?

   Face masks such as cloth or fabric masks act as a simple barrier and work as “source control”.

   “Source control” refers to preventing the wearer’s respiratory droplets from traveling into the air and onto other people when the person wearing the mask coughs, sneezes, talks, etc.

   These are not suitable for use during medical and surgical procedures in healthcare facilities, where exposure and risk of transmission of infection are higher. These masks may be used by the general public and in community settings. Please refer to MOH’s guidance and FAQs on the use of masks.

   Face masks are not regulated as medical devices under the Health Sciences Authority (HSA). Therefore, the quality and effectiveness of face masks are not regulated by HSA.

   How to choose a face mask?

   For greater effectiveness, choose face masks that have good filtration capability. Examples of such masks include those distributed by the People’s Association and Temasek Foundation.

   When selecting a face mask, look for the following specifications:

           Masks with at least 2 to 3 layers of fabric. As a general guide, the material should not be see-through when held against the light.
       
           Layers should preferably be made with different fabrics, including:
       
         Water-repellant outer layer
     
       Middle filter layer to remove particulates – this can be disposable filter inserts
Absorbent inner layer to absorb droplets from wearer’s mouth
           
 Fabrics with better filtering efficiency
       
  Fabrics with enough permeability to allow breathing
 Appropriate fit around the face and chin, with complete coverage of the nose and mouth, to prevent leakage of exhaled droplets

   Do not choose masks with exhalation valves, as these allow the escape of exhaled droplets from the wearer and expose others to the risk of infection.

  Are face masks useful?

   Disposable 3ply face mask with good filtering efficiency help prevent people who have COVID-19 from spreading the virus to others by acting as a “source control”. Wearing a mask in public places limits exposure to respiratory droplets and large particles and reduces the risk of community spread of infection. This is especially relevant for asymptomatic or pre-symptomatic infected wearers who feel well and may be unaware that they are infectious.

   These masks are particularly useful in public settings (e.g. when using public transport) when strict adherence to safe distancing may be challenging.
   As the contagious Delta variant of COVID-19 continues to spread in the U.S., you need to mask up—even if you're vaccinated. Here's how to find the right face mask for you.

   What Are N95 Masks?

   The N95 respirator is considered the gold standard of face coverings in the medical world, and even in the construction industry. These face coverings diverge from surgical masks in that the edges are designed to fit snugly to your face.

   N95 masks are made of tough, yet flexible non-woven polypropylene fiber. They're mostly round with a protrusion near the top to help cover your nose. Elastic strings stretch around your head to hold the mask in place. N95s sometimes feature a valve to make inhalation and exhalation easier, but they're not required. The mask should be labeled with "N95" on it. Watch out for typos, as these could be counterfeits.

   What Are KN95 Masks?

   KN95s are closely related to N95s, but only the latter is approved for use in medical settings in the U.S., and the reasoning is pretty simple: N95s are the U.S. standard, while KN95s are the Chinese standard for these close-fitting filtration devices. Both are rated to filter out 95 percent of very small particles.

   Due to the shortage of personal protective equipment (PPE) in the U.S. at the start of the pandemic, the CDC has authorized the use of KN95 masks as a suitable alternative for N95 masks. However, a number of hospitals and other KN95 wearers have pointed out some discrepancies in quality.

   KN95 face masks are better than surgical masks or cloth masks, according to ECRI. These are most appropriate in cases where you don't expect to come into contact with bodily fluids. Non-certified masks that use head and neck straps will also serve you better than those with ear loops.
 As the contagious Delta variant of COVID-19 continues to spread in the U.S., you need to mask up—even if you're vaccinated. Here's how to find the right face mask for you.

   Disposable nitrile, natural latex, PE, and vinyl gloves, often referred to as thin-mil gloves, are used in a variety of distinct applications. Understanding the truths about glove performance is important in selecting the right glove for each application.

   Myth #1: More Texture Means Better Grip

   One of the most common misconceptions about disposable gloves is that more texture results in better grip. In fact, texture has very little effect on grip. It is possible to make an extremely textured glove with a low grip and a smooth-surfaced glove with a high grip.

   Surface treatment is the most significant factor in the grip level of a glove. Natural latex is inherently sticky, or tacky, much like glue. Without proper processing, natural latex sticks together like a large ball of adhesive. To reduce this tack, the surface must be treated. The most common surface treatments are surface chlorination and coating. Chlorination changes the surface properties and creates a hard, lower-tack shell around the glove. Coating technology adds a new, lower-tack layer to the glove.

   Reality: Surface tack, or grip, can be controlled by the level of chlorination or the characteristics of the coating.

   Myth #2: Gloves Remain Safe Throughout Use

   Throughout use, gloves can develop holes due to degradation and wear. According to one study, after only 12 minutes of simulated clinical use, natural latex and vinyl glove defect rates increased to 9 percent and 35 percent, respectively. Without proper curing and cross-linking, nitrile can swell and develop holes or defects over time. Failure is commonly observed in the crotch between the thumb and forefinger.

   In addition to formulation and process, use factors, such as average wear time and application, affect the inuse defect rate. Buyers should consider the potential defect rate increase and the risk imposed. They should ask their glove suppliers for supporting studies on in-use testing. Buyers and users can perform a representative test themselves by wearing a pair of new, tight-fitting gloves for the prescribed use time and then removing and filling the gloves with water to see whether a hole developed.

Myth #3: Gloves Can Be '100%' Nitrile, Natural Latex, or Vinyl

   Glove suppliers frequently claim glove composition of "100%" of the respective materials. Without additives, it is practically impossible to produce a usable glove of any of these materials. Adding curatives, cross-link agents, and accelerators to nitrile and natural latex is essential to making a strong, durable glove. Vinyl requires plasticizers and activation agents. Surfactants, which help with film formulation, are another additive found in most gloves. Formulations typically require 4-10 percent of additives to make a good glove.

   Reality: Claims of "100%" nitrile, natural latex, or vinyl are not accurate.

   Myth #4: Fillers Always Diminish Glove Performance

   Fillers are used broadly in gloves. Most manufacturers use or have the ability to use fillers to help reduce the cost of making a glove. Fillers are often difficult, but possible, to detect through advanced technologies such as Thermal Gravimetric Analysis.

   Fillers help to reduce the cost of a glove and, up to certain amounts, actually can improve specific performance characteristics. For example, tear strength is significantly improved in natural disposable latex gloves when a moderate amount of calcium carbonate is added. The keyword is "moderate." Fillers up to about 15 percent are tolerable; anything above that can become detrimental to the performance and quality of the glove in use. Some manufacturers have experimented with up to 50 percent filler, with limited success.

   Myth #5: All Allergy Issues Can Be Addressed by Using Nitrile or Vinyl Instead of Natural Latex

   Glove-related allergies are a primary concern to many glove users. The belief that glove-related allergies are caused only by natural latex is a common one. Latex allergies are the most serious glove allergies because they can be systemic and cause anaphylactic shock. Latex allergies are also the most common type of glove allergies.

   Some users confuse chemical allergies with latex allergies. There are often components in both nitrile and vinyl gloves that can elicit a chemical allergy. For example, nitrile gloves, like natural latex gloves, often use carbamates or thiazoles, which can cause a skin allergy. Certain vinyl gloves use activation agents that can also cause skin allergies. In all cases, the less a glove is washed, the more chemical residue is available for potential contact to the user. Users should consult their physician if they suspect an allergy to gloves.

   Reality: Natural latex is not the only glove material that can cause allergies.

   Myth #6: 'Powder-free' Means 'Clean'

   Surface treatment is the most common way to remove powder from a glove. Two types of surface treatment are chlorination and the addition of a wax or polymer coating. Chlorination is the traditional process and requires gloves to be washed prior to packing. The washing process is designed to rid the gloves of residual chemicals.

   Wax and polymer coatings allow a glove manufacturer to "strip and pack," avoiding the chlorination and washing process. Wax and polymer coatings can leave residual chemicals that have not been properly washed. Though not always harmful, the residual chemicals can contribute to skin sensitivity or process contamination.

   Myth #7: Chemical Resistance of Powder-free Natural Latex is Similar from Glove to Glove

   As discussed in myth #6, the powder is removed from gloves by chlorination or coating treatment. The treatment type, or lack thereof, can affect the chemical resistance properties of the glove. For example, natural latex gloves achieve better overall chemical resistance when chlorinated. Chlorination changes the surface properties and creates a hard shell around the glove. This "plasticized" shell has proper ties slightly different from natural rubber and provides additional chemical resistance that would otherwise not be available. On the downside, over-chlorination can damage gloves, making them brittle and unusable.

   Myth #8: All Disposable Gloves are Basically the Same

   Disposable gloves come in several different material types. The most common types are made from nitrile, natural latex, and vinyl. Each of these types is based on commodity raw materials with price fluctuations that depend on specific market factors. In general, nitrile is often considered premium to latex, which in turn is often considered premium to vinyl. The fact is that materials are not equal in performance in all applications. Nitrile has better puncture resistance of the three and resists more chemicals overall, including oils and solvents. Latex has better tear resistance, often fits better, and provides better dexterity. Vinyl has the best electrostatic dissipation properties and resists sulfuric acid better than nitrile or latex.

   Even within the same material, there are significant differences from manufacturer to manufacturer. Other factors influencing glove performance are raw materials, formulation, process, and washing. These vary significantly from glove to glove and can result in performance differences in most applications. Typically, standards for the different materials also are not harmonized. ASTM exam glove standards have different tensile strength requirements for latex, nitrile, and vinyl. Vinyl has the most relaxed strength requirement, followed by nitrile, while latex has the highest tensile strength requirement of the three, and disposable PE gloves can withstand strong pulling and are not easy to break.

   Myth #9: Lower Priced Gloves Always Result in Cost Savings

   One of the biggest mistakes made by disposable glove buyers is buying based solely on price. The overall value of a glove is much more complicated than just the price of a box. In addition to price, buyers should consider durability in the application, safety risks, and productivity.

   Should protective suits be used when managing COVID-19 patients? 

   In its recommendations for the rational use of PPE, the WHO stated that coveralls (sometimes called Ebola PPE) are not required when managing COVID-19 patients. Headcovers (hoods) that cover the head and neck, used in the ontext of filovirus disease outbreaks, are not required either.

   The CDC recommends that healthcare personnel put on a clean protective suit upon entry into the patient room or area. However, if coveralls are used as an alternative to gowns, the CDC also recommends that healthcare workers put on a clean garment before performing patient care, with a new coverall required for each patient. 

   Should protective suits be worn when testing for the coronavirus?

   In its guidance on the appropriate use of testing for smart healthcare providers, the CDC recommends PPE that includes a gown for baggers and swabbers. Specimen transporters need only a glove and facemask.

   Similarly, gloves and facemask (if more than 6 feet from the person being tested) are required for the registrar and labeler responsible for registration, consent form and labeling the test kit.

   In addition, all participants undergoing testing should wear a facemask or cloth face covering throughout the process, only removing it during swabbing. All masks must be produced by professional mask making machine and in strict accordance with hygiene standards.