[Preventive measures against health damage due to chemicals in household products].

Chemicals in household products have been paid much attention as the main cause of health damage in consumers, such as allergic contact dermatitis. Preventive measures against health damage due to chemicals in fabrics, plastics and rubber products for household use, are reviewed, focusing on 1) the incidence of health damage due to household products, 2) causative product-chemical investigation, and 3) case studies on skin damage.

Needle fibers of an azo-dye mixture induce polyploidy in a Chinese hamster cell line CHL.

In a routine Safety evaluation of chemicals included in household products, we found a mixture of azo dyes (CMBA, main component: N-[5-[(2-cyanoethyl)ethylamino]-4-methoxy-2-[(5-nitro-2,1-benzisothiazol-3-yl)azo]phenyl] acetamide) that precipitated in the culture medium in a characteristic fiber form (around 2 - 33 microm in length) similar to that of asbestos. We compared CMBA with an asbestos, chrysotile B, in a cytotoxicity, chromosome aberration (CA), and micronucleus (MN) test in a Chinese hamster lung cell line (CHL). In the cytotoxicity test, the 50% growth inhibition concentration was 11.0 microg/ml for CMBA and 0.398 microg/ml for chrysotile B asbestos. CMBA and chrysotile B both induced polyploidy in the CA test and equal-sized binucleated and polynuclear cells in the MN test. CMBA differs from chrysotile B chemically. The former is an organic chemical and the latter is a mineral. Although CMBA is soluble in methanol and can be safely disposed by burning, it should be handled carefully when manufactured in a factory.

[Research on the marketing status of antimicrobial products and the use of antimicrobial agents indicated on product labels from 1991 through 2005].

To clarify the marketing status of antimicrobial products, descriptions on the labels of commercially available antimicrobial products were investigated from 1991 through 2005, and the results were analyzed using a database system on antimicrobial deodorant agents. A classification table of household antimicrobial products was prepared and revised, based on which target products were reviewed for any changes in the product type. The number of antimicrobial products markedly increased over 3 years starting from 1996, among which there were many products apparently not requiring antimicrobial processing. More recently, in the 2002 and 2004 surveys, while sales of kitchenware and daily necessities decreased, chemical products, baby articles, and articles for pets increased; this poses new problems. To clarify the use of antimicrobial agents in the target products, a 3-step (large, intermediate, small) classification table of antimicrobial agents was also prepared, based on which antimicrobial agents indicated on the product labels were checked. The rate of identifying the agents increased. However, this is because of the increase of chemical products and baby articles, both of which more frequently indicated the ingredient agents on the labels, and the decrease of kitchenware and daily necessities, which less frequently indicated them on the labels. Therefore there has been little change in the actual identification rate. The agents used are characterized by product types: quaternary ammonium salts, metal salts, and organic antimicrobials are commonly used in textiles, plastics, and chemical products, respectively. Since the use of natural organic agents has recently increased, the safety of these agents should be evaluated.

[Preventive measures against health damage due to chemicals in household products].

Chemicals in household products have been paid much attention as main cause of health damage on consumers, such as allergic contact dermatitis. Preventive measures against health damage due to chemicals in fabric, plastic and rubber products for household uses, are reviewed, focusing on (1) regulation and voluntary control by manufacturers, (2) incidence of health damage from household products, (3) causative product-chemical investigation, (4) case studies on skin damage and respiratory tract damage.

Monitoring of polycyclic aromatic hydrocarbons and water-extractable phenols in creosotes and creosote-treated woods made and procurable in Japan.

The recycling of disused railway sleepers treated with wood preservatives such as creosote as exterior wood for use in gardens has recently become popular in Japan. Creosote contains high quantities of polycyclic aromatic hydrocarbons (PAHs), and can lead to skin irritation and disease. In this work we have determined the amount of PAHs and water-extractable phenols in creosote and creosote-treated wood products such as railway sleepers and stakes for agricultural use that are either made or are procurable in Japan. PAHs were extracted with dichloromethane and analyzed by gas chromatography-mass spectrometry. Among carcinogenic PAHs, benz(a)anthracene was detected in the highest concentration, varying between 228 and 6328 microg/g in creosotes. Benzo(b)fluoranthene, benzo(k)fluoranthene and benzo(a)pyrene (BaP) were found in the range of 67-3541 microg/g. Almost all creosotes contained more than 50 microg/g of BaP, which is the upper limit level that is permitted in the European Union (EU). Creosote-impregnated wood products, such as brand-new or secondhand railway sleepers and foundations, contained large amounts of BaP (58-749 microg/g) and benz(a)anthracene (250-1282 microg/g). Concentrations of between 692 and 2489 microg/g of phenols were determined in the water extracts from creosotes, but the level was considerably less than the EU control value (3% by mass), and there was no correlation between the amount of water-extractable phenols and the amount of PAHs detected in each sample. The situation that consumers are free to use the creosotes containing a high concentration of carcinogens such as BaP may cause unacceptable damage to the health of persons handling these creosote products.

[Cytotoxicity of chemicals used in household products: 1997- 2004].

The cytotoxicities of chemicals used in household products were evaluated using a neutral red (NR) uptake assay. The chemicals tested during 1997-2004 were rubber additives (accelerators, antioxidants and retarders), solvents, plasticizers and biocides, such as antimicrobials, fungicides, preservatives used in paints, paper, wood and plastic products. The cytotoxicity potential of each chemical was classified by determining the concentrations inducing 50% reduction of NR uptake into Chinese hamster fibroblast V79 cells compared to control (IC50). In vivo eye irritancy of each chemical was estimated by the IC50 value. Most biocides tested showed strong cytotoxicity and had a high probability of inducing strong eye irritation.

[Examination related to revised test method for determination of formaldehyde, regulated by the law for the control of household products containing harmful substances].

In Japan, the amount of formaldehyde in textile products was regulated by the low for the control of household products containing harmful substances. Formaldehyde was determined by measuring the optical density of acetylacetone derivative of formaldehyde extracted from textiles. The household products low stated that the increase in the optical density of color development of the extract from the textile products for babies or infants within 24 months after birth should not be more than 0.05. Collaborative study decided the amount of formaldehyde equivalent to the increase in absorbance described above, and the amount was 16 ppm. There are some reports that formaldehyde causes an allergic reaction even at a very low concentration, so continuous regulation for formaldehyde in the textiles was desirable using this level of amount. We developed HPLC method for the determination of formaldehyde in textile products. Formaldehyde was determined by the direct injection of acetylacetone derivative of samples into the system equipped with ODS column and UV-VIS detector (detection wavelength 413 nm) using the mixture of acetonitrile and water as mobile phase. The linearity was obtained between a peak area or height and the concentrations of formaldehyde solution in the range of 0.0625-2 micrograms/ml. The regulation level was sufficiently detected by the present HPLC method. We recommended that the HPLC test was adopted as a reexamination method for the products may violate the regulation as well as a dimedone test.

[Validation of a method for discrimination of formaldehyde processing in textile products].

It is important to investigate a cause of formaldehyde contamination exceeding a regulation limit value in a textile product. If formaldehyde was released from a textile product itself by treatment or processing with formaldehyde, an administrative guidance is given to a manufacture. On the other hand, when the formaldehyde migrated from other textile products or a furniture stand during displaying, an improvement instruction is performed to the store. Iwama et al. [Ann. Rep. Nagoya City Public Res. Inst., 42, 11-16 (1996)] developed a method for distinguishing fabric processing and migration by additional hydrolytic extraction using hydrochloric acid solution. This study was to confirm the reliability and stability of the method for knowing formaldehyde processing on textiles. Five laboratories evaluated three samples: unprocessed textile, processed textile and unprocessed but formaldehyde-migrated textile. For a processed textile sample, amounts of formaldehyde increased by additional extractions with acidic solution, so all laboratories judged that the sample had been treated with formaldehyde. In the cases of the other two samples, such increases were not observed in the extracts using acidic solution. All laboratories reported that these samples were not processed using formaldehyde but had absorbed a different level of formaldehyde by migration. In a series of experiments, the judgement about the existence of formaldehyde processing or migration is comparatively consistent among all laboratories. This validation study concluded that the distinguishing method adopting additional extractions with acidic solution is useful to find formaldehyde processing of textile, and to deal with processing and migration separately as a cause of formaldehyde contamination.