Skin exposure to permanent hair dye compounds was assessed in 33 hairdressers using a previously evaluated hand rinse method. Hand rinse samples were collected from each hand before the start of hair dyeing, after application of the dye and after cutting the newly-dyed hair. Sixteen of the hairdressers did not use gloves during dye application, and none used gloves while cutting the dyed hair. The samples were analysed for pertinent aromatic amines and resorcinol (RES) using an HPLC method. 10 of 54 hair dye mixtures contained 1,4-phenylenediamine (PPD), 40 toluene-2,5-diaminesulphate (TDS), and 44 RES. After application of the hair dye, PPD was found in samples from 4 hairdressers, TDS in 12 and RES in 21. PPD was found in samples from 3 of the 17 hairdressers that used gloves during application of the hair dye, TDS in 5 and RES in 11. In the group that did not use gloves during the application of hair dye (n = 16) PPD was found in samples from 1 hairdresser, TDS in 7 and RES in 11. After cutting the dyed hair, PPD was found in samples from 5 hairdressers, TDS in 14 and RES in 20. Analysis of samples of newly-dyed hair cuttings revealed the presence of aromatic amines and/or RES in 11/12 samples. Our conclusion is that hairdressers' skin is exposed to allergenic compounds during hair dyeing. Exposure occurs from dye application, from cutting newly-dyed hair and from background exposure. The exposure loadings are in the level, where there is a risk of sensitization and/or elicitation of contact allergy (i.e. for PPD 22-939 nmol per hand). The glove use observed in this study was often improper, and was insufficient to prevent exposure. To reduce exposure, improved skin protection and work routines are important.

Hairdressers have an increased risk of developing occupational skin diseases due to exposure to skin irritants and sensitizers. In the present work a method of assessing dermal exposure to permanent hair dyes was developed. The sampling performance characteristics of hand wash sampling with bag rinsing were studied for five hair dye compounds. The effect of residence time, sample load and different matrices were studied. Thirty volunteers were exposed to a reference solution of these compounds and to commercial hair dye products. The sampling efficiency after 5 min residence time was between 70 and 90% for the dye components in the hair dye products. Sampling efficiency decreases with increasing residence time, making the time of sampling an important factor. Hand wash sampling should be performed as soon as possible after the work task of interest. We conclude that the sampling efficiency is adequate for measurements of dermal exposure to permanent hair dyes. Hand wash sampling with bag rinsing is a useful tool for field studies of dermal exposure assessment in hairdressers.

Objective: To assess occupational dermal exposure to permanent hair dyes in hairdressers.Methods: Dermal exposure was assessed in 31 hairdressers using a previously evaluated method, hand wash sampling with bag rinsing. The measurements were performed in hairdressing saloons during working hours. Hand wash samples were collected from each hand before start of the hair dyeing process, after application of the hair dye and after cutting the newly dyed hair. 13 of the hairdressers did not use gloves during application of the hair dye, and during cutting of the dyed hair no one used gloves. The samples were analysed for aromatic amines and resorcinol using an HPLC‐method.Results: After application of the hair dye PPD (p‐phenylenediamine) was found in samples from 1 hairdressers (148–185 nmol/hand), TDA (toluenediamine) in samples from 12 hairdressers (range 10–735 nmol/hand) and resorcinol in 22 individuals (range 19–769 nmol/hand). In the samples taken after cutting the dyed hair PPD was found in 2 hairdressers (range 36–358 nmol/hand), TDA in 14 (range 8–361 nmol/hand) and resorcinol in 20 (range 10–725 nmol/hand.Conclusion: Skin exposure to aromatic amines and resorcinol was detected in more than half of the hairdressers after application of hair dye and also after cutting newly dyed hair. To reduce exposure improved skin protection is important.

Non‐ionic surfactants, e.g. fatty alcohol ethoxylates, are considered to cause less skin irritation than other types of surfactants. However, the autoxidation of alcohol ethoxylates generates products that are both skin irritating and sensitizing, such as formaldehyde. It has been suggested that formaldehyde be used as an indicator of the degree of autoxidation of fatty alcohol ethoxylates, and thus also as an indicator of the sensitizing capacity of the product. Attempts to analyse formaldehyde in autoxidized ethoxylates using 2,4‐dinitrophenylhydrazine derivatization resulted in formation of the corresponding hydrazone not only from free formaldehyde but also from autoxidation products during the derivatization reaction. Consequently, this derivatizing agent is inappropriate for the determination of formaldehyde in autoxidized fatty alcohol ethoxylates. Focus on the content of primary oxidation products, i.e. hydroperoxides/peroxides, is suggested, particularly as they also are potent sensitizers.

In biological monitoring of styrene, the exposure is usually related to the urinary concentration of mandelic (MA) and/or phenylglyoxylic (PGA) acids in a urine sample taken after the workshift or on following morning. To study this relationship further, a single-compartment mathematical model was developed by which measured occupational repetitive uptake of styrene during a working day was related to measured excretion rates of the urinary metabolites. The model was used in practice to calculate the unknown uptake (dose) from MA and PGA excretion analyzed in urine samples. For comparison, a styrene limit dose was calculated from the exposure limit. Analytical results of samples from plastic boat builders were compared with the limit values.

In a plastic boat company we studied workers' attitudes toward wearing respiratory protective equipment and differences in styrene exposure received with and without respirators. The workers studied used either half-facepiece air-purifying or full-face air-supplied respirators as much as possible during the first day of the study. On the second day respirators were used only for short periods or-not at all. Individual styrene exposures were measured by personal air sampling in the breathing zone. When using respirators the exposure was measured both inside and outside the respirators. The styrene metabolites mandelic and phenylglyoxylic acids were determined in urine samples collected during the workday. The eleven workers studied used the respirators 52% of the time on the first day and 7% of the time on the second. The reasons for not wearing respirators were that they delayed work, were too tight and uncomfortable, made it difficult to breath, and/or became too warm. The use of respirators during work operations such as spraying, laminating, and painting reduced the styrene exposure by 56%-92%. The excretion rate of mandelic and phenylglyoxylic acids in urine collected at the end of the working day was 30%-99% lower when respirators were worn than when they were not.

Isotachophoretic methods for the determination of compounds of interest in biological monitoring are reviewed. The analytes are charged biotransformation products such as acids or amines. Comparisons are made between isotachophoretic methods and other techniques regarding sensitivity, need for preseparation or derivatization and similar technical aspects.

A method has been developed for the isocratic high-performance liquid chromatographic analysis of hippuric acid in human blood plasma. After the addition of an internal standard (3-methoxysalicylic acid), plasma samples (1 ml) were made alkaline and extracted stepwise with methylene chloride and ethyl acetate. The detection limit was 50 pmol of hippuric acid per ml of plasma. The concentrations of hippuric acid in plasma from house painters (n = 8), with long-term exposure to solvent vapours from alkyd paints, were in the range 1-21 nmol/mol (median 11 nmol/ml). These values were statistically significantly higher than those for controls (n = 9): 2-8 nmol/ml (median 3 nmol/ml).

Colour developing agents which are derivatives of p-phenylenediamine can cause contact allergy. This study was done to perform if the observed simultaneous test reactions between different colour developing agents could be explained by common contaminants, reaction products or impurities. High-performance liquid chromatography (HPLC) was used for the separation of p-phenylenediamine, 1,4-benzoquinone, hydroquinone, Metol and the colour developing agents CD-2, CD-3 and CD-4. The stability in water solutions and in petrolatum mixtures was examined for the last three substances. Samples of test preparations drawn at different stages of guinea pig maximization tests (GPMT) with colour developing agents were analysed, as well as patch test preparations for clinical use and tank solutions from developer machines. No contaminants or reaction products in common were shown in the bulk chemicals, tank solutions or test preparations of CD-2, CD-3 and CD-4. These findings and the GPMT studies imply that the simultaneous test reactions reflect cross-sensitization. The colour developing agents were stable in petrolatum mixtures, but unstable in water solutions. Therefore, fresh solutions for intradermal induction and petrolatum mixtures for topical induction and challenge were used in the final GPMT's.

Colour developing agents which are derivatives of p-phenylenediamine (PPDA), e.g. CD-2, CD-3 and CD-4, are known to cause allergic contact dermatitis and lichenoid reactions in workers at film laboratories and in photographers. Some of these patients show positive patch test reactions to more than one colour developer, and also to developers that they have not been occupationally exposed to. The aims of the study were to determine the sensitizing potential of CD-2, CD-3 and CD-4, and to study cross-sensitization between the colour developing agents and PPDA. In three separate series of guinea pig maximization tests (GPMT), animals were exposed to CD-2, CD-3 and CD-4, respectively. Challenge testing was done with CD-2, CD-3, CD-4 and PPDA in all series. CD-2, CD-3 and CD-4 were analysed with respect to purity, common contaminants and reaction products, using high-performance liquid chromatography (HPLC). Test substances used in the GPMT were analysed before and after testing, and remaining substances on the patches and on the skin were analysed, as well as bulk chemicals and tank solutions. CD-2, CD-3 and CD-4 were shown to be extremely potent sensitizers — 100% of the animals were sensitized. Simultaneous reactions to the other tested colour developing agents were found in 75%–100%, while reactions to PPDA were not seen. No contaminants or reaction products in common were detected by the HPLC analysis. The simultaneous test reactions were interpreted as cross-sensitization. Metabolization of these chemicals within the skin was, however, beyond the scope of this study.

Styrene exposure of 18 workers in fiber-glass reinforced plastic industries was measured for 30-min periods throughout each workday for a week. The styrene uptake was estimated using pulmonary ventilation measurements. All urine voidings were collected separately and the styrene metabolites, mandelic acid (MA) and phenylglyoxylic acid (PGA) were determined. The relationship between both exposure and uptake versus excretion of these metabolites was studied. Styrene metabolite concentrations and excretion rates (with 95% tolerance limits) were calculated to correspond to a constant 8-h exposure at the Swedish exposure limit level (25 ppm) or an uptake of an exposure limit related styrene dose (6.3 mmol). The tightest tolerance limits were obtained for excretion rate of MA + PGA per 24 h. The calculated biological exposure limit was 3.4 (± 0.7) mmol MA + PGA/24 h for a dose of 6.3 mmol styrene.

Eight different isotachophoretic systems for the analysis of 27 aliphatic amines are described. Complete methods including sampling and analysis procedures for the determination of eight amines in workroom air are also given. Different systems for the generation of gaseous amine standards in air are discussed, as well as sampling with washing bottles, adsorption tubes and liquid dosimeters. The methods were used in industrial environments. The isotachophoretic method is compared with gas and high-performance liquid chromatography.

Different calculations of methyl hippuric acid excretion in urine were correlated to the time-weighted average (TWA) of the xylene exposure of a complete workday for 40 paint industry workers exposed to 12 different solvents. The 8-h TWA xylene exposure varied between 0 and 865 (median 69) mg/m3. The amount of methyl hippuric acid excreted in about 24 h showed only a slightly higher linear correlation to the xylene exposure than the amount of methyl hippuric acid excreted per hour during the latter part of the workshift among the 37 subjects exposed to TWA xylene air concentrations of 0-200 mg/m3. It was concluded that the methyl hippuric acid excretion rate during the latter part of the workshift can be used for crude xylene exposure categorizations.

The N-methylmorpholine levels in workroom air in a polyurethane foam factory were determined by two methods in which midget impinger flasks were used for sampling. The analyses were performed by gas chromatography and isotachophoresis. The values obtained by the gas chromatographic method were 19% higher than those of the isotachophoretic method. Determinations of the amine in samples generated in laboratory experiments showed no statistical difference between the two methods. The mean air concentrations of N-methylmorpholine in different work areas of the factory ranged from 7 to 22 mg/m3. Urine was collected from seven workers and analyzed for N-methylmorpholine by gas chromatography. The amine concentrations and the excretion rates increased considerably during the workday.

Methods for the biological monitoring of aromatic hydrocarbons and their metabolites in the human blood and urine are reviewed. For the determination of the unchanged aromatic hydrocarbon in blood, gas chromatographic head-space analysis is recommended. The metabolites can be monitored by photometric, thin-layer chromatographic, high-performance liquid chromatographic and gas chromatographic methods. For the assessment of health risks caused by aromatic hydrocarbons, reference values and occupational limit values, expressed as biological tolerance values and biological exposure indices, have to be considered.

A method for the determination of dimethylethylamine in workroom air has been developed. Static gas standards of the amine in air were used to evaluate different sampling techniques. The analysis was performed by isotachophoresis. The sampling equipment of choice was midget impinger flasks of glass or polystyrene containing 10 ml of hydrochloric acid (50 mmol/l). The method was used in a field study of three different iron foundries where air samples were taken. The dimethylethylamine concentration found was in the range 0.5-155 mg/m3. No pretreatment of the samples was necessary, and no interfering substances from the air in the foundries affected the analysis.

An ethylenediamine-air mixture was generated in a dynamic gas mixing apparatus, and three different sampling techniques were tested. The analysis was performed using isotachophoresis. Sampling in an impinger flask containing hydrochloric acid (20 mmol/l) gave a quantitative recovery. Desorption losses were noticed when silica gel adsorption tubes were used. Cellulose filter support pads impregnated with oxalic acid were laborious to prepare, and the recovery was high only when freshly prepared filters were used. The use of impingers was found to be the most satisfactory method, and it was used for air monitoring in two factories handling ethylenediamine.

The urinary excretion of hippuric acid and o-cresol was studied after respiratory exposure of human volunteers to approximately 80 ppm (306 mg/m3 ± SD 13) of toluene for 2 h under different work loads (0, 50,100, 150 W, respectively, during 30-min periods). The diet before and after exposure varied. An isotachophoresis method for the determination of hippuric acid is described. The correlation between the total urinary excretion, excretion rate and concentration of hippuric acid, and the respiratory uptake of toluene was poor or non-existing. The same was true for the excretion of o-cresol, which 4 h after exposure was concluded amounted to 0.03–0.26% of the toluene uptake. Thus, after a short-time exposure neither metabolite proved to be a reliable measure of individual toluene uptake at varying workloads or food intake in combination with low exposure levels.