Issue 21
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Category		Title		Author
Guest Article		Skin Protection in the Workplace *		Joachim Kresken

Importance of occupational skin protection

Numerous occupations in industry, skilled and unskilled trades, hospitals, medical practices and private households involve frequent washing of the hands, intensive work in wet conditions, or regular skin contact with potentially irritant or allergenic substances (for example, metal salts, cooling lubricants, solvents, detergents, disinfectants or hairdressing products). Due to the often simultaneous influence of these load factors, the natural skin barrier may become distressed or damaged, especially in persons with sensitive, dry skin, which is low in sebum. As a consequence, cumulative-toxic or, in extreme cases, allergic contact eczemas may occur, especially on the hands (Figures 1 to 3).


Figure 1: Wear dermatosis affecting an employee of a cleaning business as a consequence of intensive "wet" work.

Figure 2: Cumulative-toxic eczema affecting a painter after regular use of nitro dilutions to clean the skin.



Figure 3: Allergic contact eczema affecting an assistant who works in a photo laboratory, caused by developer solution.

Severe or recurrent occupational eczemas qualify as occupational diseases under the German regulations governing occupational diseases (Berufskrankheiten-Verordnung). Affected persons may have to change their job or place of work, and in the worst cases may even have to stop working completely. Statistical surveys carried out by the German accident insurers reveal the extent of the problem: For example, according to the annual report of the German association of occupational accident insurers (Hauptverband der gewerblichen Berufsgenossenschaften) (1), in 1995 alone more than 18,000 notifications of suspected occupational dermatoses were received by the German accident insurers. More than 7,000 of these were confirmed.

The costs incurred by the occupational accident insurers for treatment, rehabilitation and compensation measures amounted to more than DM 300 million. If the costs of the German health insurance funds, and the employers’ absenteeism-related costs are also included, the total economic loss caused by occupational dermatoses is probably at least DM 1 billion per year in Germany alone.

As well as the cases of occupational dematosis that are reported to the accident insurers, there are cases that do not appear in the statistics. These must also be taken into consideration. Although any attempt to estimate the number of undisclosed cases is necessarily speculative, it can be assumed that the figure is considerable. Fear of dismissal, in particular, is one reason why far from all cases of jobrelated dermatosis are reported to the occupational accident insurers. Moreover it can be assumed that there is a high incidence of occupational dermatoses among workers who are not compulsorily insured – for example, home workers.

General skin protection measures

In view of the considerable costs and the possible social disadvantages for those affected, a high priority is generally assigned to prophylactic measures against occupational dermatoses (2-5). Such prophylactic measures include the correct choice of job; technical protective measures in the workplace; wearing protective clothing; using suitable skin protection and skin care products; and the provision of mild skin cleansing systems (2).

The choice of an occupation that suits the job-seeker’s skin is the most important prerequisite for the prevention of occupational dermatoses. It has long been known that people with a susceptibility to atopic dermatitis are at greater risk of suffering from eczema if they take up jobs that distress the skin, such as in the metal or metalworking industries, hairdressing or other “wet” jobs (3). Before they choose a particular job, or change their job or place of work, they should ask a dermatologist to test their skin to ensure that they are kept away from any activity that would be dermatologically unsuitable for them.

In the workplace, collective technical protective measures should always take priority over personal measures. Technical solutions aimed at totally, or at least partially, eliminating the possibility of employees coming into direct skin contact with harmful substances, can best be achieved in large companies by organizational changes in work procedures or by replacing aggressive substances with harmless or far less aggressive substitutes. In smaller companies, as well as in the home and the private sphere, such measures are usually impracticable. The emphasis must therefore be on wearing protective clothing, especially protective gloves, and using skin protection and skin care products.

When protective gloves are worn, care must be taken to ensure that the glove material has been sufficiently tested for resistance to the materials against which it is supposed to provide protection. Permeable gloves not only provide no protection, but under some circumstances they can even reinforce the effects of harmful substances – for example, by the occlusion effect of the glove material (3, 5). Moreover, if closely fitting gloves are worn for a long period of time, heat and moisture may build up, causing the skin to swell and soften, with subsequent decomposition of perspiration and buildup of odors. Other constraints on wearing protective gloves apply in workplaces where the sense of touch is extremely important and where it must be possible to move the fingers freely. These considerations clearly reveal why, for many tasks, prophylactic measures must be limited to the use of suitable skin protection and skin care products and to the provision of mild skin cleansing systems.

Skin protection and skin care products

In the work sphere, a distinction is made between special skin protection and general skin care products, depending on why and when they are used. General products are mostly applied after work to maintain or restore the function of the stratum corneum and can be primarily tailored to the individual type of skin of the person using them. This is naturally easier to achieve in the private sphere than in a work setting, where skin care products must be available for a number of people with different types of skin. As a compromise, most companies provide creams and lotions of the oil-in-water (O/W) emulsion type, which should not only be readily absorbed by the skin, but should also have a sufficiently high lipid content (at least 20 percent). Formulations with a very low lipid concentration and a correspondingly high water content can cause the skin to become drier, especially in the case of people with a dry skin type, which is low in sebum, and can, in consequence, increase the risk of eczema (3, 4). Such persons should, therefore, use products of the water-in-oil emulsion type, which have a more pronounced refatting action, rather than O/W emulsions.

Table 1
Specialty skin protection preparations (from 4)
Noxae		Skin endangerment characteristics		Necessary product properties
Water and water-miscible working substances (e.g. rinsing and cleansing agents, desinfectants, cooling lubricants with admixed water		Drying out of the skin, due to loss of natural moisturizing factors from the outermost skin layers		Hydrophobic, high lipid content
Alkaline working substances (e.g. lyes)		As above, but the skin's ability to neutralize alkalis is also overtaxed		As above, but also weakly acidic to neutral pH
Water-immiscible working substances (e.g. organic solvents, oils, cooling lubricants without admixed water)		Defatting of the skin through removal of the lipid from the intercellular cavities of the stratum corneum		Water-soluble, low-fat or non-fat, high content of solids or film-forming polymers
Intensive soiling, or working substances that cling strongly to the skin (e.g. used oil, adhesives, resins, paints)		Skin is more difficult to clean, use of strong-acting skin cleansing products is necessary		As above, but with added specialty emulsifiers to reduce adhesion and simplify cleansing the skin
Working substances with hard, sharp-edged surfaces (e.g. sand, wire wool, glass fibers)		Mechanically induced irritation or microlesions		Astringent through addition of special tanning agents
Occlusive protective clothing (e.g. rubber gloves, rubber boots)		Build up of moisture with softening of the skin (maceration) and decomposition of perspiration		as above
Fluctuating or not clearly definable exposure to harmful substances		Widely varied		Dualistic action principle (e.g. water-soluble base with addition of special tanning agents)
UV irradiation by sunlight (when working in the open air) or from artificial sources of light (e.g. when welding)		Erythema formation, increased risk of skin cancer, damage to connective tissue, photo-toxic and photoallergic skin reactions		UV-absorption and/or reflection with the help of UV-A/UV-B filter combinations or pigment additives, waterproof

In contrast to the general skin care products, special skin care preparations are used exclusively before and during work. Their main purpose is to selectively reduce contact with substances that are harmful to the skin. Preparations are available for making skin cleansing easier, and for a variety of other purposes (Table 1). Factors that influence the choice of such products include the condition of the user’s skin, the material-compatibility and the physicochemical properties of the harmful substances concerned. In general, strongly lipophilic topical preparations are recommended against water-miscible noxae, and hydrophilic bases against water-immiscible ones (2-6). This concept, which is largely based on theoretical considerations, practical experience, and the results of in vitro experiments, could not be verified with this degree of clarity in more recent in vivo experiments (7-10). For example, a strongly lipophilic product, which, on the basis of preliminary in vitro tests, had been expected to provide good protection against a model irritant (sodium lauryl sulfate), proved practically ineffective under the in vivo conditions of the repetitive irritation test, while two other preparations with a significantly lower lipid content were convincingly effective under the same test conditions (Figure 4).

The few in vivo methods that have been developed for testing the efficacy of skin protection preparations are currently being tested by the skin protection work group of the German association for occupational and environmental dermatology (the Arbeitsgemeinschaft für Berufs- und Umweltdermatologie – also referred to as the ABD) to determine whether they can be used as routine test methods (11). In contrast to the best protective gloves, however, even the most effective of the tested skin protection preparation provides only partial protection, for a limited period of time, against contact with the relevant harmful substances. For this reason, inadequate descriptions of this product group (for example, “invisible glove”), which could give users a false sense of safety, should be avoided.

Skin protection through mild skin cleansing

Employees in many workplaces have to wash their skin several times each day with soaps, syndets or other skin cleansing products. This means, especially for persons who tend to have dry skin, low in sebum, that there is increased risk of developing cumulative-toxic and allergic contact eczemas. Even the water used to wash the skin removes considerable amounts of the natural moisturizing factors localized in the stratum corneum. Moreover, surfactants and other components of skin cleansing products can remove the skin’s sebum, causing impairment of the epidermal barrier function. Both processes cause increased transepidermal water loss (TEWL), resulting in the clinical picture of dry, rough skin (Figure 1). This skin condition, which can be described as a wear dermatosis, prepares the ground for the further progress of the disease. Surfactants and other job-related irritants, as well as potential contact allergens, can penetrate more easily into the deeper skin layers and trigger the pathogenetic mechanisms for a cumulative-toxic or an allergic contact eczema (Figure 5).

Efforts to ensure mild cleansing of the skin should be focused on reducing the risk of these side-effects as far as possible. Several aspects should be taken into account, concerning both personal behavior and the choice of the skin cleansing product that is to be used (Table 2). The wide variety of soils that are encountered in the industrial sector require a wide range of different skin cleansing products whose action is based on a number of different cleansing principles and a mild cleansing effect. Depending on the type and intensity of the soil, a choice can be made between simple soaps and syndets, hand cleansers that contain abrasive components, and specialty products containing additives such as solvents, reducing agents or other components that enhance the cleansing action (2-4).

Table 2
Conditions for mild skin cleansing
·	Use skin cleansing measures only when essential (no unnecessary washing)
·	Use skin cleansing products that are tailored to the type and intensity of the relevant soiling and do not have an excessively strong cleansing action
·	Avoid skin cleansers that contain surfactants with a strong irritant action
·	Use additional skin protection and skin care products

Within the individual product classes, the skin compatibility of the relevant commercial products depends primarily on the types of surfactants used. Comparative irritation tests with various methods have shown that there are sometimes considerable differences between the individual classes of surfactants in terms of their irritant effect (Table 3). These differences are reflected in the individual commercial preparations (12-15) and should be taken into account in the choice of product. Skin cleansers based on surfactants with a strongly irritant effect, such as soap raw materials or fatty alcohol sulfates, should be avoided, especially by persons with dry skin, which is low in sebum, or with sensitive or damaged skin. Instead they should use products based on surfactants with better skin compatibility, such as ether carboxylic acids, sulfosuccinates or alkyl polyglycosides. Only under these circumstances can skin cleansing contribute to skin protection in the workplace.

Table 3
Classification of some important classes of surfactants in terms of skin compatibility (from 4)
Surfactant class		Skin compatibility
Alkyl polyglycosides ("sugar surfactants")		good to very good
Ethoxylated fatty acid glycerides
Betain derivatives
Castor oil sulfonates
Sulfosuccinates
Ethoxylated fatty alcohols
Isethionates
Fatty alcohol ether sulfates		moderate
Alkylolamides
alpha-Olefinsulfonates		poor
Secondary alkane sulfonates
Alkylbenzolsulfonates
Fatty alcohol sulfates
©Skin Care Forum

References

(1) Hauptverband der gewerblichen Berufsgenossenschaften (Hrsg.), Übersicht über die Geschäfts- und Rechnungsergebnisse der gewerblichen Berufsgenossenschaften im Jahre 1995, Sutter Druckerei, Essen (1996)
(2) Kresken, J.; Reinigung, Schutz und Pflege der Haut am Arbeitsplatz, Pharm. Ztg. 137, Nr. 37, Supplement Dermopharmazie (1992) 3-9
(3) Tronnier, H.; Kresken, J.; Jablonski, K.; Komp, B.; Haut und Beruf, Strategien zur Verhütung berufsbedingter Hauterkrankungen, Grosse Verlag, Berlin (1989)
(4) Kresken, J.; Maßnahmen zur Verhütung berufsbedingter Hauterkrankungen, in: Dicke, W.; Mehlem, P. (Hrsg.), Alles über Hautschutz, Hautreinigung, Hautpflege, 3. Aufl., 51-69, Wirtschaftsverlag NW, Bremerhaven (1993)
(5) Gloor, M.; Köhler, S.; Gehring, W.; Hautschutzmaßnahmen, ein Stiefkind prophylaktisch dermatologischer Tätigkeit, Z. Hautkr. 66 (1991) 201-207
(6) Wulfhorst, B.; Schwanitz, H.J.; Zur Wirksamkeit von Hautschutzpräparaten, Arbeitsmed. Sozialmed. Umweltmed. 29 (1994) 84-92
(7) Frosch, P.J.; Kurte, A.; Efficacy of skin barrier creams (IV), the repetitive irritation test (RIT) with a set of four standard irritants, Contact Dermatitis 31 (1994) 161-168
(8) Grünewald, A.M.; Lorenz, J.; Gloor, M.; Gehring, W.; Kleesz, P.; Lipophilic irritants, protective value of urea- and of glycerol-containing oil-in-water emulsions, Dermatosen 44 (1996) 81-86
(9) Schlüter-Wigger, W.; Elsner, P.; Efficacy of four commercially available protective creams in the repetitive irritation test (RIT), Contact Dermatitis 34 (1996) 278-283
(10) Kresken, J.; Klotz, A.; Rosenberger, V.; Gewerblicher Hautschutz: Wirksamkeitsprüfung nichtwassermischbarer Hautschutzsalben im repetitiven Irritationstest (RIT), in: Korting, H.C.; Braun-Falco, O.; Gloor, M.; Hautreinigung und Hautpflege: Nutzen und Risiko, Berichtsband über ein Symposium am 6./7. September 1997 in Dessau, Springer Verlag (in press)
(11) Schnetz, E. et al.; Development and evaluation of an in vivo test model for cumulative irritation, first results of a multi center study, poster presentation, 3rd International Symposium on Irritant Contact Dermatitis, 2.-4. October 1997 in Rome
(12) Kresken, J.; Boullon, G.; Syndets und ihre Inhaltsstoffe, Pharm. Ztg. 134 (1989) 2545-2551
(13) Kresken, J.; Eckert, J.; Wassilew, S.W.; Zur Problematik von Hautverträglichkeitsprüfungen, Untersuchungen von Hautreinigungsmitteln in Modifikationen des Duhring-Kammer-Tests, Dermatosen 37 (1989) 63-66
(14) Kresken, J.; Wassilew, S.W.; Untersuchungen zur Irritationspotenz gewerblich verwendeter Hautschutz-, Hautreinigungs- und Hautpflegepräparate, in: Meyer-Falcke, A.; Jansen, G. (Hrsg.): Verhandlungen der Deutschen Gesellschaft für Arbeitsmedizin, 29. Jahrestagung in Düsseldorf vom 26.-29. April 1989, Gentner Verlag, Stuttgart (1990) 173-176
(15) Gottfreund, J.; Jander, B.; Schweitzer, K.-D.; Chemischer Aufbau und dermatologische Leistung von Syndets, SÖFW-Journal 120 (1994) 755-761



From 1984 to 1988 Dr. rer. nat. Joachim Kresken was head of the medical research department of a major manufacturer of skin protection, skin cleansing skin care preparations. Since 1989 he has worked as a self-employed druggist in Viersen, Germany, and as a part-time technical journalist and scientific consultant. He was a founder member of the Society for Dermopharmacy in 1995, and is its president.