Differences in protective gloves

Many pharmacy teams are currently working not only with face masks but also with protective gloves.

These are changed not only regularly but also frequently disinfected. But not all materials are stable against alcohol. Some people also have a latex allergy or cannot tolerate certain other substances in the glove. Wearing them also puts a strain on the skin: an occlusion effect softens the skin and can make it more prone to allergies. Depending on the area of application, the products have different AQL values. This value is significant when handling hazardous substances. Each material offers advantages and disadvantages — however, the pharmacy should pay attention to some factors when choosing gloves.

The most commonly used materials for disposable gloves include latex, nitrile, polyvinyl chloride (PVC), polychloroprene (neoprene) and polyvinyl alcohol (PVA).

Different materials — different properties

Latex gloves still enjoy great popularity because of their wearing comfort. Especially in areas where a lot of dexterity is required, users prefer this natural product. Latex has a good resistance against many acids and alkalis. However, they are permeable to oils and many solvents. After disinfection with alcoholic solutions, the material often appears soapy, which leads to the assumption that the material will leak. While tests show that latex gloves under the influence of ethanol become permeable after ten minutes, the material even condenses on contact with isopropanol.

In principle, glove disinfection during wearing is possible, but cannot be generally assessed due to the widely varying disinfectant compositions and glove properties. For a factual statement, the manufacturer should always be consulted. In addition, the allergy risk of latex should not be neglected. The material is well suited as an over glove when worn by two pairs — it should not be worn directly on the skin for long periods of time.

Nitrile gloves are more resistant to many chemicals, including oils. They are permeable to many solvents like acetone or dichloromethane. They are therefore only suitable to a limited extent for use in the laboratory for identity testing. When filling and decanting hazardous substances, thicker chemical gloves should generally be used. Polyethene gloves have hardly any elasticity so that the basic shape of the gloves differs from others. The entry point must be more expansive to put on the glove than with other materials. These gloves are known from hairdressing supplies; they often come with hair tints.

Protective gloves made of polyvinyl chloride are particularly suitable for work with acids and alkalis and are partly resistant to organic compounds. The advantage of gloves made of neoprene is their durability. Polychloroprene has excellent physical properties and is more resistant to weathering and ageing than gloves made of other materials.

When subjected to mechanical stress, material properties such as tear resistance, elongation, and abrasion are essential. In hand sales, the gloves are subject to heavy wear, not least due to frequent typing and pulling on drawers. Here, gloves that are free of vulcanization accelerators are generally at a disadvantage. Vinyl gloves in particular, which do not contain these substances, tear quickly — at the same time they are considered to be the most compatible.

AQL value

The AQL value is not related to the protective effect of the glove. The value, which usually ranges between 0.65 and 4.0, indicates how many gloves in a batch were defective — the lower the AQL value, the fewer disposable gloves in a batch were defective within a sample. AQL stands for “acceptance quality level”. For a batch size of 10,000 gloves, for example, this results in a sample size of 200 gloves within the GMP guidelines. These are checked at least visually. All specimens that show tears, holes or other defects are rejected. With six faulty gloves, for example, a value of 1.0 is obtained when a special AQL table is included.

AQL values are determined for every product in the industry. If a manufacturer has defined an AQL value of 1.0 with six defective gloves for a batch size of 10,000 pieces, the entire batch is discarded if seven or more defective copies are found. Pharmacies can read the AQL value in the datasheet. As an aid to selecting suitable gloves, the higher the requirement profile for a product, the lower the approved AQL value should be.

No powdered gloves

Powdered gloves have a special wearing comfort. The powder molecules make it easier to put on — the hand slides in better, even if it is not completely dry. The powder does not soften the skin so quickly. Nevertheless: Powdered gloves are outdated, especially latex gloves. Latex is a natural product with increased allergy potential. The proteins from the milk of the tropical rubber tree are responsible for this. The risk increases with increasing content of latex proteins in the product. Powdered gloves usually contain significantly higher protein concentrations that accumulate on the powder. When putting on and taking off the gloves, these are swirled and distributed by the air. The use of powdered latex disposable gloves is no longer permitted.

Vulcanization accelerators can cause a knockout.

So-called vulcanization accelerators are used to give gloves their shape. These are chemical substances that make rubber solid faster or at lower temperatures. Organic materials containing sulfur and nitrogen are most frequently used. Derivatives of benzothiazole, a compound from the group of sulfur-nitrogen heterocycles, are particularly suitable.

Vulcanization accelerators can be divided into different speed groups. For example, there are ultra-accelerators, which include substances such as dithiocarbamates, thiuram disulfides and monosulfides and xanthogenates. These are followed by the semi-ultra-accelerators with substances such as mercaptobenzothiazole and aldehydamine condensation products. Moderately strong accelerators are dibenzothiazyl disulfide, diarylguanidines such as diphenyl guanidine, arylbiguanides such as tolylbiguanide, hexamethylenetetramine and aldehyde ammonia. Only weak accelerators are for example triarylguanidines and diarylthioureas.

Thioram allergy is the most common form of allergy when it comes to incompatibility with vulcanization accelerators. It is triggered by allergens of dithiocarbamates. The symptoms are similar to a contact allergy. It expresses itself through Skin rash in the form of pustules, blisters, pimples and wheals, skin redness and swelling. Those affected almost always suffer from severe itching and burning of the skin. In rare cases, anaphylactic symptoms have been reported. The rash can be treated with cortisone ointments. As long as the skin is irritated and open, gloves should not be worn. After the symptoms have subsided, gloves that have been treated with vulcanization accelerators during manufacture should be avoided. The manufacturers state whether these substances have been used, and certificates indicate the extent to which these substances have been washed out of the product afterwards.

Hand care

In general, proactive hand care is to be preferred — it should not be creamed only after the skin is cracked. When wearing gloves, the hands should be washed with soap-free surfactants at the beginning of the shift and then rubbed with a skin protection cream. After the product has been completely absorbed, the hands can be disinfected. The gloves should only be put on when the skin is dehydrated, as otherwise, the skin may swell additionally. A fallacy: the hands are still low in germs after taking off the gloves. Over time, more endogenous germs are formed under the gloves — coronaviruses and other pathogenic germs, however, remain on the outside of the glove. Therefore, when stripping the gloves, care should be taken to ensure that the gloves are not touched from the outside. In case of doubt, disinfect again.