What does the abbreviation AQL mean on the packaging of gloves? How to choose gloves? Recommendations for practitioners Acceptable level of quality.

HOW TO CHOOSE MEDICAL GLOVES

The rapid spread of dangerous infections, in particular AIDS and viral hepatitis, determines certain requirements for medical gloves as the main means of protecting health workers and patients. The effectiveness of protection is achieved by maintaining the mechanical integrity of examination or surgical gloves during manipulations.

What are the requirements for working with gloves?

1. It is necessary to select gloves of the right size. The choice of gloves depends on the nature of the manipulation being performed.
2. Always wear clean gloves before carrying out manipulations associated with contact with mucous membranes or damaged skin.
3. Use sterile gloves for handling under aseptic conditions.
4. Manipulations with blood or other body fluids must be done with latex or nitrile gloves (gloves reduce the amount of blood inoculum that is transmitted by accidental prick with a used needle).
5. The use of an extra pair of gloves reduces the frequency of damage when working with sharp tools by 2-4 times.
6. Remove gloves very carefully to avoid contamination of the skin of the hands. Torn or leaking gloves are unsuitable for use.

In order to choose the right medical gloves, it is necessary to take into account the nature of the manipulations performed, the time the gloves were used, the presence of a history of allergic reactions, etc. medical personnel, primarily surgeons, require high tactile sensitivity of the skin of the hands. At the same time, not only the thickness of the glove material is important, but also its elasticity, the ability to maintain reliable contact with the skin throughout the entire time of work; with biological fluids.

How to choose the right glove size.

When using surgical gloves, it is very important to choose the right size. To find out your glove size, it is necessary to measure the circumference of the palm without the thumb, positioning a centimeter above the bones and not pulling the palm over them. The size of the gloves corresponds to the circumference of the hand in its widest part.

Wrist girth, see glove size

For examination gloves, the international classification SML (small-medium-large) is used.

So size XS corresponds to size 5-6,

Size S - 6-7 size,

Size M - 7-8 size,

Size L - size 8-9,

Size XL - 9 and up

Rules for trying on gloves:

Gently fold back the edge of the cuff of the glove.
Put on a glove on four fingers to the middle of the palm (to the base of the thumb).
Put a glove on your thumb.
Carefully straighten the cuff of the glove on the arm to the wrist.
With light movements of the second hand, straighten the glove according to the shape of the hand. (Do not spread the glove between the fingers) Take off the gloves carefully, first pulling each finger, and then holding them at the same time (except the big one).

Gloves are available sterile and non-sterile. At the same time, it should be understood that sterile ones are better, because when they are packed in an envelope, additional quality control takes place. Potentially, the reject rate of non-sterile gloves is always higher. Non-sterile gloves are divided into packed in boxes (in box) and packed in bulk (in bulk), the latter will have a higher rejection rate.

What is ACL?
AQL (acceptable quality level) - an acceptable level of quality.
In conditions mass production it is impossible to control the quality of each product, so the control is applied only to a small part of the products, and the quality of this part should give an idea of the quality of the entire batch.
In the Russian Federation, in terms of tightness, AQL should not exceed 2.5 for diagnostic gloves, and for surgical gloves - 1.5. For comparison, according to the European standard, the coefficient should not be lower than 1.5. This means that out of a batch of, for example, 10,000 pairs, 630 units are sampled. They are then subjected to destructive tests: tension with water, inflation, microbiological control, pH measurement. If, at the end of the check, the number of defective units is 20 or less, then the entire lot is allowed for sale, with the exception of defective products. At AQL 1.0, the number of defective units must be no more than 16.
That is, the lower the AQL score (1.5 is below 2.5; 1.0 is below 1.5, etc.), the products meet higher quality standards.

As a result of many years of work, we have come to the conclusion that the gloves of most Russian importers declared with AQL 1.5 do not meet these requirements. If you keep this in mind, your euphoria about amazing prices will be greatly overshadowed. In practice, when you buy cheap gloves, you will pay for all the waste that you cannot use, and your costs for rejection, and do not forget about compensating doctors if they remain dissatisfied. There is no fantasy, as a result, the same price as for high-quality gloves is obtained.

It is known that the vast majority of medical gloves are disposable. The manufacturer does not give any guarantees for gloves when they are reused. If the seller inspires you the opposite, then most likely he is simply incorrect. In order to reuse gloves, they must be washed, dried, powdered, packed and sterilized. No one can guarantee that during these operations the destruction of the material will not occur, moreover, such processing does not even control the integrity of the gloves, not to mention microcracks. Why on earth wear gloves if you are not sure of their integrity?

Unfortunately, skin irritation and allergies from contact with latex gloves are not uncommon. If you buy cheap gloves, you will have to keep in mind that the number of technological washes of such gloves is reduced to a minimum, and the level of proteins in such gloves is quite high. For sensitive skin, this guarantees an allergic reaction.

And finally, the most important thing: when you have decided which gloves you need, do not forget to evaluate their level of quality. Unfortunately, it is often limited to the selection and testing of glove samples - this is not enough.

It would be nice if you asked for an international certificate (CE, TUV) - this is some kind of guarantee that the product matches the quality of the samples that you were asked to test. With such a high level of competition that has developed in the world, there are practically no manufacturers of gloves left who do not have these certificates. It is clear that all European and American manufacturers, by definition, are required to have them. By the way, there are very few of them left: the lowest cost of production of gloves made of natural latex in the countries of Southeast Asia. It produces up to 80% of the world's gloves. European and American surgeons have long been wearing Malaysian gloves. The question is not the country of origin of the gloves, but their quality.

If the answer to a question about the quality of gloves is “made in America or in Europe”, do not hesitate to ask for a CE or TUV certificate.

So, with all the variety of gloves, we can say that they are good and not very good. For questions about the purchase of gloves, the quality of which is checked and does not raise questions, write to: [email protected]

Checking a batch of goods is an important and complex process. In any batch there is a marriage, and with large volumes, you cannot manually check each unit. How to quickly inspect products and make sure that the quality level is acceptable? How to more or less accurately find your boundary between rejection and acceptance of a batch if a defective product is found?

How many units need to be checked?

There are precise answers to these difficult questions, and you can find them in the Acceptance Quality Limits or AQL tables. As the name implies, they define the limiting level of quality at which a batch of products will not upset the consumer and you. So, after checking a relatively small number of samples, the batch can be accepted.

The authors of the AQL tables focused on ISO standard 2859, but there are no general limits for each market and product type. In each segment they are different, and for small consumer goods this level is higher than for cars.

The level is determined as a percentage, that is, you have researched the market, your consumer and decided that the maximum allowable percentage of defective products is 2.5% of the entire batch. So your AQL will be 2.5%.

AQL tables already have metrics for your product group, including lot size, inspection level, and AQL itself.

And if you need to check a batch of high-end chairs with a volume of 3,500 pieces with a medium (usually choose this level) second-level check, then your sample size code is L.

We look at the second table and see that L = 200 units of goods from the entire batch. This is our sample size. We keep in mind that for high value products the AQL is lower and we choose levels of 0%, 1% and 2.5% for each defect category.

But first you need to divide the potential defects of your product into three categories.

The first is critical defects. The product cannot be used, does not meet safety requirements, or does not perform its functions.

The second is significant defects. The product can be used, but it is unlikely to be bought.

And the third-- Defects are minor, when deviations from the specification do not affect the popularity of the product.

We also chose an AQL of 4 for minor defects and 2.5 for major defects. It turns out that the batch can be accepted if during the inspection no more than ten significant and fourteen minor defects are found. If we find seven minor and eleven major defects, then such a batch does not meet the standard. If seven major defects and 10 minor defects are found, then the lot is accepted.

Do not forget that a separate check is needed for each group of goods in one segment, and defective products can be bought and sold at a reduced price. And in case of difficulties, Asianinspector experts will always help you. Write and call us!

Medical gloves are one of the main means of ensuring infectious safety in a medical institution. Wide variety of medical gloves Russian market At present, as well as the aggressive marketing policy of a number of manufacturers, they do not always allow healthcare facility staff to adequately understand the types of gloves and choose the right products to ensure safe work with patients.

All properties (characteristics) of medical gloves can be divided into 3 main groups: the main ones are present in any glove, additional ones - specialized gloves may have, dubious ones - various marketing tricks of manufacturers and suppliers, designed, among other things, to reduce possible competition.

The main properties of a medical glove include:

1) material of manufacture.

The main manufacturing material is latex - an emulsion of rubber particles in an aqueous solution. There are natural or synthetic rubbers, depending on the type of rubber, natural latex is distinguished, as well as nitrile, polyisoprene, polychloroprene latex and vinyl (polyvinyl chloride, "plastic" latex).

Natural latex consists of more than 60% polyisoprene particles, which allows us to consider polyisoprene gloves as the closest in properties to conventional latex. The advantages of natural latex are widely known: gloves made of this material stretch well, fit the hand, are soft and elastic. At the same time, they contain a significant amount of proteins that cause allergic reactions and are not resistant to alcohols, oils, and esters. The world standard for the presence of proteins in a natural latex glove is less than 50 µg/g, determined by the Lowry method (colorimetric method). A number of manufacturers offer gloves with a protein level of less than 20 µg/g, and in early 2011, gloves made of natural latex, completely free of proteins (MPXX technology - maximum protection), appeared.

Nitrile latex perfectly resists the action of alcohols, aldehydes, phenols and acids, which allows the use of nitrile gloves in laboratories, when working with aggressive environments, when cleaning rooms in medical facilities. In addition, synthetic gloves are absolutely non-allergenic, as they do not contain proteins, but, nevertheless, very often cause contact dermatitis when long work. It is impossible to call nitrile gloves hypoallergenic. The disadvantages of nitrile gloves include low elasticity and extensibility, which prevents their widespread use in surgery.

Polychloroprene (neoprene) and polyisoprene gloves are quite expensive, so they are mainly used as surgical gloves. There is no reasonable need to use examination gloves made of neoprene and polychloroprene, since they are similar to nitrile in terms of resistance to chemicals. At the same time, the use of such gloves during surgical operations allows you to provide the highest level of protection for all members of the surgical team.

Vinyl gloves made from PVC - polyvinyl chloride, a short-lived and rather harmful substance. These gloves are cheap, but they have one important drawback: they are easily permeable to any proteins (including blood proteins) and microorganisms, which does not allow them to be used even for a short-term examination of patients.

Currently there are gloves having 2 different layers. for example, DermaGEL gloves from the Polish company Mercator Medical have an inner layer of nitrile or polyurethane, which gives the glove extra strength, insulates the skin from the action of natural latex proteins and greatly facilitates donning. The start of production of such hybrid gloves, combining the properties of different materials, is an important step towards creating a new level of infectious protection.

2) the presence or absence of powder

The negative properties of the powder used in the manufacture of gloves are widely known. Initially, the use of powder was due to the technological process of production, to prevent sticking of the walls after removal from the mold. In this case, multiple cleaning and rinsing steps were used to make powder-free gloves, resulting in a significant price difference between powdered and powder-free gloves. At present, such cleaning is used only by manufacturers with outdated equipment; at most enterprises, powder is excluded from the technological process, which has significantly reduced the difference in price. In order to keep the gloves from sticking together after demolding, most factories use surface modification - this process will be discussed later.

Powder is the strongest absorbent, attracting and holding proteins and microorganisms. Thus, it is a source of infectious danger, and enhances the allergic effect of natural latex on the skin. Numerous studies have shown a significant role of powder in the occurrence of postoperative complications, adhesions and scars, the occurrence of allergic reactions in both patients and healthcare facility staff, and the spread of nosocomial infections.

3) textured surface

The texture of the outer surface improves the grip of the medical instrument. During production, a textured surface is formed by using solutions of formers - chemicals that act on the outer surface of a glove that is not yet ready, not completely dry. In general, it is necessary to separate the concepts of a textured (textured) and micro-rough (micro rough) surface. In the second case, the surface of the glove changes very little and, in general, in terms of its contact properties, the microrough surface is closer to smooth than to textured. In addition, it is important to note that Russian GOSTs require the manufacturer to provide a minimum thickness of 0.08 mm for smooth sections of examination gloves, and 0.11 mm for textured ones. For surgical gloves, these values are 0.10 and 0.13 mm, respectively. Neither a smooth glove with a thickness of 0.07mm nor textured glove with a thickness of 0.10mm cannot be used for medical purposes.

4) presence / absence of a roller

The roller is a structural element of the glove, with the help of which the glove is fixed on the wrist. The main requirement for gloves with a roll is that the roll must be rolled up inside the glove, if it is rolled outward, the space between the roll and the outer surface of the glove is a source of significant infectious hazard. During a surgical operation, this space cannot be treated with a skin antiseptic and is a kind of storage for carrying bacteria. In the absence of a roller, a mandatory component of the glove should be a reinforced or reinforced cuff that fits snugly around the wrist. Gloves without a roll without a reinforced cuff are made from ordinary gloves by simply cutting off the roll, they do not fit and do not stick to the wrist and their use is not justified.

5) AQL

AQL (Eng. Acceptable Quality Level, Guaranteed Quality Level) - the maximum allowable number of defects in a batch of samples of a certain size. AQL is one of the most important quality indicators for mass production. In AQL testing - an acceptable quality level - a certain number of samples of manufactured products are selected according to a carefully defined procedure for random testing. These randomly selected samples are then tested in accordance with approved state standards and specifications. Based on the results obtained, a conclusion can be drawn about the quality of the entire batch of products. The higher the product quality requirements, the stricter the testing requirements.

Basically, they test medical gloves for water resistance. This is a procedure for determining the ability to retain water. 1000 ml is poured into the glove. water, while the glove should not leak for a certain period of time.

Thus, AQL is a statistical procedure for determining the quality of a glove.

The lowest AQL level allowed for a medical glove according to Russian GOST is 2.5, according to the European standard EN 455 - 1.5. There are medical gloves with an AQL of 1.0 or 0.65. clearly this indicator can be estimated as the probability of having defective items in a batch of 1000 boxes of gloves, 50 pairs each. With an AQL of 2.5, the probability that there will be no defective gloves in the box is only 3%, i.e. virtually every box in a batch will contain one, two, or more defective items. With AQL 1.5, the probability of having defective products in the box can be estimated at 22%, and with AQL 1.0 - at 6-8%.

Thus, a slight increase in the AQL level leads to a significant guaranteed reduction in the number of defective gloves in the lot.

6) Length and thickness

As mentioned above, Russian GOSTs (52238 - 2004 and 52239 - 2004) require the manufacturer to provide a minimum thickness of 0.08 mm for smooth sections of examination gloves, and 0.11 mm for textured ones. For surgical gloves, these values are 0.10 and 0.13 mm, respectively.

The length of an examination glove should not be less than 220mm, for a surgical glove - 255mm. Moreover, European standards EN 455 are even more stringent and do not allow lengths less than 240 and 280 mm for examination and surgical gloves, respectively.

At the same time, I would like to note that more and more diagnostic gloves are produced with a length of at least 290mm. Long gloves are absolutely essential when used as protective against harmful chemicals - in laboratories, when cleaning, when working with cytostatics or to protect against viral infections.

Additional properties of a medical glove include the following:

1) Anatomical shape.

GOST 52238 - 2004 indicates the presence of an anatomical shape as a prerequisite for classifying this glove as a surgical glove. In general, the shape of a glove with the thumb extended forward is called anatomical, which significantly reduces hand fatigue during work and long-term surgical operations. Anatomically shaped gloves are more expensive to manufacture than a regular (flat) shape and can only be worn on the corresponding - right or left - hand. For a more accurate selection of sizes for such gloves, digital (from 5.5 to 9) designations are used instead of the usual alphabetic ones for diagnostic gloves (XS, S, M, L, XL). Size XS corresponds to sizes 5.5 and 6, S - 6, 6.5 and 7, M - 7, 7.5 and 8, L - 8 and 8.5.

There is the concept of “improved anatomical shape”, which is a shape with fingers bent towards the palmar side, which reduces the load not only on the thumb, but also on all the others.

2) Sterility

The sterility of the glove is ensured by sterilization, i.e. complete release from all types of microorganisms, including bacteria and their spores, fungi, virions, as well as from prion proteins. Sterilization can be carried out by thermal, chemical, radiation, filtration methods; in industrial volumes, surgical gloves are sterilized by chemical (ethylene oxide gas sterilization) or radiation (gamma radiation) methods. Thermal sterilization of non-sterile gloves is carried out in the healthcare facility. Both radiation and gas sterilization are absolutely safe for the consumer and equally effective in removing microorganisms. Often the same manufacturer of gloves can be sterilized with both gamma radiation and ethylene oxide. As a rule, to confirm sterilization, an indicator is applied to the box, which changes its color with sufficient exposure intensity and confirms sterility.

3) Surface modification

Modification of the inner or outer surface of a medical glove is a common process designed to make the surface smoother. The modification of the inner surface is used to facilitate donning, including on wet hands, the modification of the outer surface is designed for more convenient work with small tools so that the contact surfaces of the fingers do not stick together.

There are 2 main methods of surface modification: chlorination (chlorination) and polymer treatment.

Chlorination- this is the treatment of a glove with perchloric acid, it can be single or double (on both sides). As a result of chlorination, latex particles are destroyed and form a smooth film on the surface. There is a process of partial dehydration, ie. removing water, making the glove feel drier to the touch. Chlorination can be carried out production line(online chlorination), and by soaking gloves in a perchloric acid solution for a long time. Online chlorination is one of the main ways to prevent gloves from sticking together after removal from the mold, this step has replaced technological process dusting. The concentration of chlorine in this case is extremely small and the process practically does not affect the properties of the glove. Double chlorination, carried out for a long time, significantly changes the properties of the glove. The destruction of the latex particles leads to a decrease in the elasticity and extensibility of the glove. Uncontrolled long-term chlorination leads to the appearance of an intense yellow color, makes the latex permeable to proteins and microorganisms, traces of chlorine on the surface of the glove can adversely affect both the doctor and the patient.

At the same time, an increase in the intensity of exposure has practically no effect on the properties of the surface - the surface becomes smooth even with not very strong chlorination.

Another method of surface modification is polymer treatment. The function of the polymer coating is to improve donning and prevent sticking of the glove. Almost any polymer can be used for surface treatment, polyurethane or silicone are most commonly used. When processing with polymers, it is not the formation of an additional functional layer, but a kind of smoothing of surface irregularities. The polymer-treated surface does not protect the skin from the action of latex proteins and does not interfere with the contact of natural latex with the skin, therefore it cannot serve as a protection against allergic reactions or contact dermatitis.

The questionable properties of medical gloves include the presence of a moisturizer (glycerin, tocopherol), extracts of aloe vera, chamomile, various compounds to improve skin trophism without confirming clinical efficacy and indicating the quantitative composition.

Lots of product entering inspection may have some proportion of nonconforming items. This proportion of nonconforming units is characterized by the level of quality. A quality level is any relative measure of quality obtained by comparing observed values with specified requirements.

The quality level can be expressed as a percentage of nonconforming items (the ratio of the number of nonconforming items to the total number of items) or as the number of nonconformities per 100 items of product (the ratio of the number of nonconformities to the total number of items).

With selective control, it is impossible to establish the actual level of quality in the controlled batch of products, but only its assessment can be obtained. The accuracy of this estimate depends on how justified the control plan is. As such an assessment, when controlling by a quantitative attribute, the limit value of the controlled parameter in the sample is used, and when controlling by an alternative attribute, the quality level is used.

Under acceptable AQL quality level when considering the sequence of batches, the average level of quality is understood, which, for the purposes of product acceptance, is satisfactory.

An acceptable level of quality for a particular inspection plan corresponds to a high probability of acceptance, provided that the level of nonconformities in the inspected lot does not exceed the specified AQL value. However, a given AQL does not mean that no more than the specified percentage of nonconforming items is allowed in the lot. In any case, it is preferable to have no mismatch than to have any percentage, and the more it can be reduced from AQL, the better. Reducing the percentage of nonconforming items increases the likelihood of acceptance for each lot.

The choice of the required AQL value is carried out by agreement between the supplier and the consumer and is negotiated in the contract.

In many cases, AQL is a trade-off between a consumer's preferred quality and one a manufacturer can afford, as stringent requirements are more difficult to meet in manufacturing process and more control costs will be required to verify that they are met.

Choosing the correct AQL value is one of the most important tasks when using statistical acceptance testing. The question of lowering or raising AQL should be economically justified. Choosing an unreasonably low AQL value will cause the supplier to incur losses from rejecting a significant proportion of good products, and setting an unreasonably high AQL value will force the consumer to accept batches of products containing a large number of nonconforming products.

Acceptable level quality serves as the basis for determining control standards in the case of batch sequence control (reference indicator in the tables of STB GOST R 50779.71 and tables of Appendix A of STB GOST R 50779.75).

The AQL value determines the severity of the sampling.

Assign different AQLs to groups of nonconformities or different types of nonconformities.

When setting the value of an acceptable quality level for products that are controlled by several quality indicators, the acceptable quality level is determined in two ways:

AQL is established for individual quality indicators, and then for products as a whole;

· AQL is established for products as a whole, and then for individual quality indicators.

AQL values of no more than 10 are established for both the percentage of nonconforming product items and the number of nonconformities per 100 product items. An AQL value greater than 10 is set only for the number of nonconformities per 100 units of production.

It is recommended to use the preferred AQL values (26 values from 0.010 to 1000), however, if this is not possible, the STB GOST R 50779.71 system allows you to build control plans for other AQL values (STB GOST R 50779.70).

In AQL-based sampling, inspected lots taken from the process with a quality equal to or better than the AQL will in most cases be accepted.

In a continuous series of sampling lots, AQL is the quality level corresponding to the average satisfactory process limit.

AQL is a chosen boundary between acceptable and unacceptable process average values. It does not describe a sampling plan, but is a requirement of what production should be and a convenient value for determining an acceptable process.

When assigning AQL, it must be taken into account that it is a quality indicator required in production. The manufacturer is recommended to produce batches of medium quality better than AQL. On the other hand, this quality must be realistically achievable and at the same time justified from the point of view of the consumer. With a properly designed and managed process, it is possible to produce products with a lower percentage of nonconforming units than AQL. By obtaining a better average process, the overall cost of producing and inspecting better quality products is reduced.

Taking into account the requirements of the customer, it is necessary to check that it is not too high, and also take into account the intended use of the controlled products and the consequences of failures. If at more product failure can be considered as a signal to replace a nonconforming product, then a fairly mild level of AQL is acceptable. If this failure results in damage to a costly and critical piece of equipment where replacement is not possible, a more stringent AQL is required.

The process average is the average quality level of a series of lots submitted for inspection (lots resubmitted for inspection are excluded). The process average refers to what is actually produced, regardless of the controls carried out.

The evaluation of the average process is not an integral part of the control scheme, but it is important in itself. Both the inspector and the manufacturer are interested not only in decisions about successive lots, but also in the long-term picture of the quality of production.

With two-stage and multi-stage control, a number of special rules must be observed. Only the results of the first sample are used to evaluate the average process.

In some cases, it is recommended to exclude abnormal results, but this rule should be applied with great care. This can be done with confidence when the abnormal results are due to a special cause that has already been eliminated. Further, in this case, data are given, including and not including anomalous results, to show the presence of these inconsistencies.

If there are many characteristics or multiple AQL classes, the averages of the individual processes should be evaluated.

Ultimate quality LQ – the level of quality at which, for sampling purposes, the probability of acceptance is low when considering a single lot. Ultimate quality is a reference indicator in STB GOST Ρ 50779.72. When inspecting a single lot, this corresponds to a level of quality, expressed as a percentage of nonconforming items or a number of nonconformities per 100 items of product, at which a low probability of acceptance is required for sampling purposes. Marginal quality actually corresponds to undesirable quality. To ensure lot acceptance, the proportion of nonconforming items must be well below the LQ (typically less than a quarter of the LQ).

Average output quality AOQ is the expected average quality level of the outgoing product after control at a given value of the input quality level. Unless otherwise specified, the average output quality is calculated over all accepted lots plus all rejected lots after sweeping and replacing nonconforming units with appropriate ones. Often used approximation:

(average output quality) = (process quality before inspection) x (probability of acceptance)

AOQL average output quality limit- the maximum value of the average output quality among all possible values of the quality level of the output products for a given plan for sampling and elimination of inconsistencies in all rejected lots

Similar to the concept of AQL, the concepts of average output quality (AOQ) and its limit (AOQL) are justified only with a large number of consecutive lots presented in a certain sampling system. The lot will be accepted if the number of nonconforming items in the sample is less than or equal to the acceptance number. If the number of nonconforming units is greater than or equal to the rejection, the lot will not be accepted. With an average process level close to AQL, most lots will be accepted. If the quality of the process does not change and rejected lots are rejected rather than corrected, sampling does not affect the quality.

In some cases, when the movement of products occurs between departments, and not enterprises, the rejected batch is checked by continuous control with the removal of non-conforming units from it (replacement with appropriate units is possible). This is called culling control.

During the inspection with sorting out, the batch is either accepted without further control, or in case of rejection, a complete inspection of each unit is carried out with the withdrawal or replacement of all non-conforming units with the appropriate ones. In the first case, the output quality practically corresponds to the input, in the second - all products correspond specifications. Even if the input quality p does not change, the output quality can change from batch to batch, taking on the values p or 0, depending on whether the batch was accepted or submitted for inspection with culling. Nevertheless, it is possible to consider the average output quality over a long period, when the input quality does not change and is equal to p. This average quality will be no worse than p, and with complete control of a large proportion of batches, it can be much better.

The term “average output quality” can be thought of as the average percentage of nonconforming items in a large number of lots from a process that continuously produces quality p. All lots are tested and evaluated with the same sampling plan, which has the probability of accepting the lot P a. Rejected lots are (in theory) cleared of nonconforming units. As a result of control with sorting out, on average, 100 R a % of batches do not contain non-conforming units, and 100 (1 - R a) % of batches that have passed only selective control and accepted from the first presentation contain 100 p % of non-conforming units (minus a number of items withdrawn from samples under control). The average output quality, expressed as a percentage of nonconforming units, is approximately 100(P a x p)%. The approximation is acceptable provided that lot size N is ten or more times larger than sample size n.

The output quality can be good both because of the good input quality and because of the complete control of a number of batches. In addition, there is an intermediate input quality p for which the average output quality has a maximum value. This value is the AOQL average output quality limit. This is not the limit of the output quality of any single batch, nor is it the limit of the actual output quality averaged over a small number of consecutive batches. In the case of a large number of them, the actual average output quality in this sequence will differ slightly from this AOQL. With variations in the input quality p, the actual quality can be much better than AOQL. Therefore, it is more efficient to estimate the real average quality directly than to rely on AOQL as an upper bound.

Process mean is the average quality level of a series of batches supplied for inspection (lots repeatedly submitted for inspection are excluded). This concept is different from AQL, AOQL or LQ, which can be calculated or selected, and is not a characteristic of a particular sampling plan. The process average refers to what is actually produced, regardless of the controls carried out.

The evaluation of the average process is not an integral part of the control scheme, but it is important in itself. Both the inspector and the manufacturer are not only interested in successive batch decisions, but also in the long-term picture of production quality. It is recommended to keep records of process average data, which is an effective measure to improve product quality and necessary information when choosing a sampling plan.

Operational characteristics of the sampling plan

When applying control plans, batches of products are accepted or rejected with some probability less than one. The probability of accepting an inspected lot depends on the proportion of nonconforming items in that lot. If there are no nonconforming items in the lot, then there cannot be any in the sample, and such a lot will in all cases be accepted with probability equal to 1. As the proportion of nonconforming items in the lot increases, the probability of accepting the lot decreases. If the entire batch consists of nonconforming units of production, then such a batch will in all cases be rejected with a probability equal to 1.

The function that sets the probability of acceptance of a controlled batch of products, depending on the input quality level, is called the operational characteristic.

The operational characteristic curve shows the mathematical expectation of the percentage of accepted batches of products. These values are average values which correspond to the actual values only for a large number of production batches under consideration.

The probability of accepting a lot of products depends on the sample size, control standard and quality level in the lot.

With an increase in the sample size (with the other two initial data unchanged), the probability of accepting a batch of products decreases.

For the supplier, increasing the sample size is unprofitable, as it increases the risk of rejecting a good batch of products; on the contrary, it is beneficial for the consumer, since his risk of accepting defective products is reduced. With the weakening of the requirements for the rigidity of the control standard (also with unchanged initial data), the probability of accepting a batch of products increases, which is beneficial for the supplier and disadvantageous for the consumer.

To meet the requirements of the supplier and the consumer at the same time, a compromise is necessary. As such a compromise, there should be an acceptable level of quality agreed between the supplier and the consumer.

Control Plans

The control plan is understood as a set of requirements and rules that should be observed when controlling a batch of products. The set of requirements and rules is understood as the volume of the controlled lot, the level and type of control, the type of sampling plan, the sample size, control standards, etc.

Sampling plan - a set of data on sample sizes and control standards - acceptance and rejection numbers (by an alternative attribute) or limit values of a controlled parameter in a sample (by a quantitative attribute).

Statistical acceptance control scheme - a complete set of sampling plans in combination with a set of rules for applying these plans.

Depending on the number of samples selected for control, single-stage, two-stage, multi-stage and sequential control plans are distinguished.

A single-stage control plan is characterized by the fact that the decision on the acceptance of a batch of products is made based on the results of control of only one sample.

From a batch of products with a volume N the sample size is extracted n z z less than or equal to acceptance number A C z greater than or equal to the rejection number R E, the batch is rejected.

This plan is applied in the following cases: the cost of the inspection is low, the duration of the inspection is too long and the lot cannot be held until the end of the inspection. The plan is characterized by the largest sample size. A diagram of a single-stage plan is shown in the figure.

Figure - Scheme of a single-stage statistical acceptance control.

A two-stage control plan is characterized by the fact that the decision to accept a batch of products is made based on the results of control of no more than two samples, and the need to select a second sample depends on the results of the control of the first sample.

From a batch of products with a volume N the sample size is extracted n 1, which determines the number of nonconforming units z1. If the number of nonconforming units z1 less than or equal to the acceptance number of the first stage of control A 1, the party is accepted; if the number of nonconforming units z1 greater than or equal to the rejection number of the first stage R1, the batch is rejected. If the number of nonconforming units z1 is within the limits between the acceptance number of the first stage of control A 1 and marriage number of the first stage R1, move on to the next level of control. From a batch of products, a sample is taken with a volume n 2, which determines the number of nonconforming units z2. If the sum of the number of nonconforming units at the first and second stages of control ( z1 + z2) less than or equal to the acceptance number of the second stage of control A2, the party is accepted; if the sum of the number of nonconforming units at the first and second stages of control ( z1 + z2) greater than or equal to the rejection number of the second stage R2, the batch is rejected.

This plan should be used if a single-stage design cannot be accepted due to the large sample size and a multi-stage design due to the long duration. The scheme of the plan is shown in the figure.

Figure - Diagram of a two-stage statistical acceptance control.

A multi-stage control plan is characterized by the fact that the decision regarding the acceptance of a batch of products is made based on the results of the control of several samples, the maximum number of which is set in advance, and the need to select a subsequent sample depends on the results of the control of previous samples.

The scheme of multi-stage statistical acceptance control resembles the scheme of two-stage statistical acceptance control. At each stage of control, a sample of size n is taken from a batch of products with a volume of N, in which the number of nonconforming units z is determined. If the sum of the number of nonconforming items at all inspection levels is less than or equal to the acceptance number for that inspection level, the lot is accepted; if the sum of the number of nonconforming items at all stages of control is greater than or equal to the rejection number of this stage, the lot is rejected. If the sum of the number of nonconforming items at all stages of control is between the acceptance number of this stage of control and the rejection number of this stage , move on to the next level of control. Control stages (according to STB GOST Ρ 50779.71) cannot be more than seven.

This plan should be used when the time required to select and control items is short and the cost of testing is high.

Ya. Yu. Kostarenko, General Manager of Ansell in Ukraine and Moldova, Kyiv

The main means of protecting the hands of medical personnel are latex medical gloves, the use of which has increased significantly over the past decade. This is primarily due to the spread of infectious diseases and the protection of medical personnel. With the increasing demand for medical gloves, their supply is also expanding. In addition to the main competitors traditionally present on the Russian medical market, there are also new little-known manufacturers with cheap products. But cheap doesn't mean quality.

In recent years, the problem of quality has become not just relevant, but super-relevant - due to the ever-increasing number of HIV-infected people infected with hepatitis. Now protection is required not only for patients, but also for doctors themselves. Thus, the only reliable means of protection are medical gloves made of natural or synthetic latex, the quality of which determines the health of both the patient and the doctor.

The quality of gloves is characterized by the following parameters:

allergenicity (cleanliness of gloves in terms of allergen content). Ansell gloves are characterized by a low protein content according to the liquid chromatography method under high pressure(HPLC) allergenic chemicals based on thin layer chromatography (TLC) data;
strength and resistance to mechanical damage: natural latex undergoes a vulcanization process. With careful observance of all norms of vulcanization, latex becomes impervious to bacteria and viruses. But if the technology fails, then defects appear in the gloves, and they no longer protect the medical staff from infections, in particular from infected blood.

The first and most common type of marriage is microcracks and holes.

The second is the uneven thickness of the glove (it will most likely tear when pulled).

The third is gloves, the length of which does not meet the standard (you cannot tuck the sleeve of a dressing gown into a short glove). All of the above reasons are explained by one thing - the desire of the manufacturer to save on raw materials. In this case, production becomes cheaper along with a decrease in the quality of gloves.

However, the most important criterion by which gloves are chosen is the so-called AQL coefficient (Acceptable Quality Level - “acceptable quality level”).

In the conditions of mass production, it is impossible to control the quality of each product, so the control is applied only to a small part of the products, and the quality of this part should give an idea of the quality of the entire batch. According to the European standard, the coefficient should not be lower than 1.5. This means that out of a batch of, for example, 10,000 pairs, 630 units are sampled. They are then subjected to destructive tests: tension with water, inflation, microbiological control, pH measurement. If, at the end of the check, the number of defective units is 20 or less, then the entire lot is allowed for sale, with the exception of defective products. At AQL 1.0, the number of defective units must be no more than 16.

ANSELL, being the world's largest manufacturer of latex products, including medical gloves, traditionally maintains a high level of quality in its products. All gloves have an AQL of 1.5, and some, such as Derma Clean, have an AQL of 0.65.

Was held comparative analysis gloves with the most competitive products of WRP, Sempermed, ARCHDALE.

All of these gloves comply with the European Standard and GOST RF in length and thickness, but the maximum length of WRP and ARCHDALE surgical gloves is 286-295 mm, while Nutex, Medi’Grip and other special gloves have a length of 295-304 mm. The length of the glove is of great importance, as it allows for better protection in the forearm area.

In terms of thickness, ANSELL gloves have the most optimal thickness - 0.20-0.25 mm (according to GOST - 0.10-0.30), which provides good tactile sensitivity and at the same time the necessary strength. Gloves ARCHDALE and Sempermed (0.16-0.22) do not provide the necessary strength and are often torn in the area of the fingers and when the cuff is pulled.

In terms of conditional strength, all surgical gloves have approximately the same indicators.

Exam powdered gloves - Exam Tex Plus - the longest (245-251 mm), the shortest - Sempermed (237-246 mm) and WRP Confit (240-248 mm), ARCHDALE - 247-250 mm, their thickness is also different (table . one). In terms of conditional strength, the indicators are approximately the same.

In terms of toxicity, Ansell gloves have the lowest level of toxicity: surgical - 71%, examination - 73.6% at a rate of 70-120%.

In addition to the above, one of the important advantages of ANSELL is a wide range of gloves. There are no universal gloves, each area of surgery requires a special glove and only ANSELL can currently meet this requirement.

The demand for powder-free gloves is on the rise thanks in large part to the educational and outreach activities carried out by ANSELL. Almost all competing companies produce powder-free gloves, the advantages of which, compared with powdered ones, are well known to everyone. But the advantage of Ansell powder-free gloves is that the inner surface is treated with silicone instead of chlorinated, which provides better protection against contaminated blood serum and pathogens and longer use of the glove, since silicone does not absorb grease.

To distinguish high-quality products from low-quality products, you need to carefully study the packaging, which contains all the basic information about the product. If the gloves are made by a reputable company that supplies its products to various countries of the world and works on common standard, it duplicates this information in the languages of all consumer countries. Another important sign of the quality of gloves is the packaging itself. A special coating protects the gloves from the damaging effects of ozone.

masks

Main characteristics of TECNOL masks

Material: outer and inner layer - viscose, which creates additional comfort compared to competitive products, where polypropylene is used as the inner layer.

The filter does not contain fiberglass: polypropylene.

Bacteriological filtration efficiency: 95% from microparticles - 1.0 micron for standard masks and 0.1 micron for special masks.

Construction: SONTEC II - ultrasonic rolling of layers, creating additional convenience and comfort.

All standard masks are 3 ply, Fluid Shield is 4 ply.

The presence of a nose clip along the entire length of 100% aluminum does not weigh down the mask.

Differential pressure (DELTA P) - 0-5. Almost all masks have (DELTA P) less than 2, which means easy breathing and coolness of the air.

The term of use is at least 4 hours for standard masks and 10-12 hours for special ones.

TECHNOL has developed a method for testing masks for resistance to liquid penetration (P.S.I) Fluid Penetration (Strike Throughout) Resistant testing.

During surgical operations, as a result of damage to the blood vessel, the blood flow at high speed comes into contact with the protective mask. The speed of the collision depends on several factors, the most important of which is the patient's blood pressure. TECHNOL has developed a device that can simulate fluid flows from a damaged blood vessel at a given blood pressure. The simulated blood pressure is based on the velocity of fluid released from a timed air valve. 2 cm3 of synthetic blood was thrown onto the mask from a distance of approximately 40 cm. After testing, each mask sample was checked visually for liquid penetration into the inner layer of the mask. If traces of blood are visible on the inside of the mask, then these samples do not pass the test. Out of 32 samples, 29 must pass the specified test.

After testing, the results were calculated equivalent to blood pressure.

Blood pressure results are classified according to 3 systemic characteristics. The system of characteristics classifies the resistance of the mask to liquids, subdividing the splash protection factor (SPF) into 5, 10, 15. Accordingly, 5 is a low level of protection, 15 is the maximum (Table 2).

All standard masks Lite One, Care bare, Cone Classic etc. have SPF - 5, and all Fluid Shield masks - 15. But standard masks are not intended for such purposes.

Powder for gloves: what you need to know

It would seem that a very modest piece of equipment for doctors is powder for gloves, but it is under the vigilant control of the FDA (Food and Drug Administration) authoritative organization in the United States and often becomes the subject of serious scientific discussions. The role of powder is important and responsible: with its help, we easily put on and take off gloves, it is a kind of “dry” lubricant. In medicine, talc has long been used for these purposes, but the FDA banned its use in 1972, as it turned out that talc penetrates the skin and accumulates in the body. Today, all manufacturers have switched to powders based on grain starch, but, alas, they are also very far from perfect and are considered a source of serious health risks. medical workers and patients.

Experts, not without reason, suggest that cornstarch powders can cause granulomas, fibrosis, adhesions, contamination of donor organs, peritonitis, visceral obstruction, and fistula formation. In 1971 U.S.F. required manufacturers to place on each package of surgical gloves the following instructions: after putting on the gloves, remove the powder from them with a damp sterile sponge, sterile towel or other similar means. Tests have shown that conventional methods of washing gloves are not only outdated and ineffective, but also can act on starch dust, increasing its ability to penetrate into the body.

Powders for gloves are fraught with danger not only for the patient. They may not have the best effect on the health of medical workers. Almost 35% of physicians who have to constantly wear medical gloves have some skin problems from time to time.

Let's consider some of them in more detail.

Irritant contact dermatitis - accompanied by dry skin, the formation of crusts, hard blisters and horizontal cracks in the skin; all this happens against the background of itchy dermatitis on the back of the hands under gloves. Causes include frequent handwashing, strong surgical cleansers and exfoliators, detergent powders, exposure to glove powders, and prolonged exposure to airless gloves with hands.

Allergic contact dermatitis, also known as a Type IV reaction, is on the rise among physicians using latex gloves. This is due to the fact that a lot of chemical additives are introduced into the material from which gloves are made - supposedly to speed up the manufacturing process, increase elasticity, ductility, strength of gloves, and extend their service life. Unfortunately, many of them negatively affect the condition of the skin and provoke the development of an allergic reaction. The symptoms are very unpleasant: red rash, blisters on the finger zones, abscesses and horizontal cracks. The disease manifests itself a few days after contact with harmful chemicals and may not be limited to the “glove zone”, but spread all the way to the forearm.

Immediate contact dermatitis refers to the first type of reaction and manifests itself as an allergy to natural rubber latex. Clinical studies show that the water-soluble latex proteins themselves can become the root cause of the disease, as they are able to "migrate" to the skin even through glove powders. Symptoms can range from immediate contact dermatitis (bruising and inflammatory reaction, eczema) to acute respiratory conditions.

However, glove powders themselves are not allergens, they are natural adsorbents that only absorb latex proteins and transfer the allergens to the skin. But inhalation of particles of the substance that makes up the powder can lead to various respiratory diseases.

Powdered gloves from different manufacturers differ in the degree of allergenicity. So you need to carefully choose gloves (powdered or unpowdered) for work and pay attention to the allergens contained in them. Glove powder can also "confound" the results of laboratory diagnostic tests, which, you know, can result in misdiagnosis and subsequent incorrect treatment. Imagine if the tests for HIV infection are “mixed up”, in this case, any interpretation, both positive and negative, will lead to tragedy.

In addition to moral and physical suffering, this problem also brings serious material losses. Agree that a person who has skin irritations will no longer be able to properly perform his duties, or even lose his ability to work, that is, the employer will have to think about replacing him.

Now let's look at the question from the other side, that is, from the point of view of the cost of hospitalization periods, which, if a patient develops allergic reactions that accompany his underlying disease, will certainly increase; therefore, additional funds will be required for his re-treatment and additional procedures.

In general, the conclusion is clear: you should carefully weigh the pros and cons before purchasing certain gloves. The decisive factors in choosing these products should not only be size, ease of use or price, but also the composition of the powder used in them.

The quality problem of gloves can be solved in two ways:

replacing starch with another powder that would be effective as a lubricant but would not give allergic reactions;
using only non-dusted gloves.

The advantages of non-dusted gloves over powdered ones are obvious, which is confirmed by dispassionate statistics: the scale of their use is increasing by 30% annually.

No sensitization! Another source of allergization is latex gloves. Air analysis in institutions where powdered gloves with a high content of latex protein were used revealed a fantastic amount of dust allergens per unit volume, while in rooms where doctors worked in latex-free, low-allergenic gloves, the air was several orders of magnitude cleaner.

Latex hypersensitivity usually manifests itself in the form of pruritic dermatitis, rhinitis, asthma and anaphylaxis. Such diseases affect 8-12% of medical workers. True, it should be noted that in recent years, active measures have been taken to protect specialists who use latex gloves in their work, in particular, contact dermatitis is being prevented, which is the main and most common result of latex protein exposure.

Scientists have also determined that the latex protein, which interacts with starch, enters the respiratory tract in the form of dust and also causes allergic sensitization. In addition, latex antigens can enter the body through the skin, both healthy and damaged by contact dermatitis. In fact, contact dermatitis often precedes other skin or respiratory illnesses in healthcare workers. This indicates the need for immediate measures to improve the safety of gloves used by physicians. It does not matter how this will be done: whether by eliminating powders or by developing safer materials, the main thing is to save people's health and reduce material costs. And the consequences of inaction in this matter can be very sad. Let me just remind you that prolonged contact with an allergen, in this case with powder substances and latex protein, can ultimately lead to such a dangerous disease as asthma - and this is already a serious pulmonary disorder that can force a person to leave the profession and significantly limits it. opportunities.

The very first step to improve the situation is to provide all healthcare professionals, especially those in hospitals, with exclusively latex-free or low-allergenic, non-dusted gloves. If we want to eradicate the problem of latex hypersensitivity in the health sector, then the measures mentioned above must be implemented as quickly as possible.