Abstract  The principal aim of the study was to estimate the level of exposure to organic solvents of graffiti removers, and to identify the chemicals used in different cleaning agents. A secondary objective was to inform about the toxicity of various products and to optimise working procedures.

Exposure to organic solvents was determined by active air sampling and biological monitoring among 38 graffiti removers during an 8-h work shift in the Stockholm underground system. The air samples and biological samples were analysed by gas chromatography. Exposure to organic solvents was also assessed by a questionnaire and interviews.

Solvents identified were N-methylpyrrolidone (NMP), dipropylene glycol monomethyl ether (DPGME), propylene glycol monomethyl ether (PGME), diethylene glycol monoethyl ether (DEGEE), toluene, xylene, pseudocumene, hemimellitine, mesitylene, ethylbenzene, limonene, nonane, decane, undecane, hexandecane and gamma-butyrolactone. The 8-h average exposures [time-weighted average (TWA)] were below 20% of the Swedish permissible exposure limit value (PEL) for all solvents identified. In poorly ventilated spaces, e.g. in elevators etc., the short-term exposures exceeded occasionally the Swedish short-term exposure limit values (STEL). The blood and urine concentrations of NMP and its metabolites were low. Glycol ethers and their metabolites (2-methoxypropionic acid (MPA), ethoxy acetic acid (EAA), butoxy acetic acid (BAA), and 2-(2-methoxyethoxy) acetic acid (MEAA)) were found in low concentrations in urine. There were significant correlation between the concentrations of NMP in air and levels of NMP and its metabolites in blood and urine. The use of personal protective equipment, i.e. gloves and respirators, was generally high.

Many different cleaning agents were used. The average exposure to solvents was low, but some working tasks included relatively high short-term exposure. To prevent adverse health effects, it is important to inform workers about the health risks and to restrict the use of the most toxic chemicals. Furthermore, it is important to develop good working procedures and to encourage the use of personal protection equipment.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM WATER POLLUTION LC-50

Abstract  Anthramycin (ANT) was the first pyrrolobenzodiazepine (PBD) molecule to be isolated, and is a potent cytotoxic agent. Although the PBD family has been investigated for use in systemic chemotherapy, their application in the management of actinic keratoses (AK) or skin cancer has not been investigated to date. In the present work, anthramycin (ANT) was selected as a model PBD compound, and the skin penetration of the molecule was investigated using conventional Franz diffusion cells. Finite dose permeation studies of ANT were performed using propylene glycol (PG), 1,3-butanediol (BD), dipropylene glycol (DiPG), Transcutol P® (TC), propylene glycol monocaprylate (PGMC), propylene glycol monolaurate (PGML) and isopropyl myristate (IPM). The skin penetration of BD, DiPG, PG and TC was also measured. Penetration of ANT through human skin was evident for TC, PG and PGML with the active appearing to "track" the permeation of the vehicle in the case of TC and PG. Deposition of ANT in skin could be correlated with skin retention of the vehicle in the case of IPM, PGMC and PGML. These preliminary findings confirm the ability of ANT to penetrate human skin and, given the potency of the molecule, suggest that further investigation is justified. Additionally, the findings emphasise the critical importance of understanding the fate of the excipient for the rational design of topical formulations.

Abstract  Toxline abstract: Rept. for 19 Jun-12 Sep 90. See also PB92-196179. Sponsored by National Toxicology Program, Research Triangle Park, NC. The laboratory supplement accompanying a report on the developmental toxicity of dipropylene glycol provides test methods used in the study, as well as information on breeding and caring for the test rats. Detailed chemical analysis methods are also provided.

Abstract  The use of chemical dispersants during oil spill responses has long been controversial. During the Deepwater Horizon (DWH) oil spill, 1.8 million gallons of dispersant, mainly Corexit 9500, were applied in offshore waters to mitigate the human health and coastal environmental impact of surface oil contamination. To evaluate the potential impact of the dispersant on marine life, 18 species, representing important ecological and commercial taxa, were tested using low-energy, dispersant-only water accommodated fractions (WAFs) of Corexit 9500 and standard acute toxicity test methods. All prepared WAFs were analytically characterized. Analyses included the two dispersant markers found in the dispersant and evaluated in samples collected during the DWH Response, dioctylsulfosuccinate sodium salt, and dipropylene glycol n-butyl ether (DPnB). The median lethal and effective concentrations (LC/EC50s) were calculated using a nominal exposure concentration (mg/L, based on the experimental loading rate of 50 mg/L) and measured DPnB (µg/L). Results ranged from 5.50 to > 50 mg/L dispersant and 492 to > 304,000 µg/L DPnB. Species sensitivity distributions of the data demonstrated that taxa were evenly distributed; however, algae and oysters were among the more sensitive organisms. The calculated 5% hazard concentration (HC5) for DPnB (1172 µg/L) was slightly higher than the USEPA chronic criteria of 1000 µg/L and substantially higher than all measured concentrations of DPnB measured in the Gulf of Mexico during the DWH oil spill response.

Abstract  Aerobic biodegradation of tripropylene glycol (PG3) was investigated under the conditions of the OECD screening test 301E and the Continuous Flow Activated Sludge Simulation test (CFAS). A modified two-chamber facility with a denitrification stage was used for the CFAS test. Primary PG3 biodegradation was measured by the HPLC with fluorimetric detection and analyte derivatisation. Metabolites were identified by LC-MS with electrospray ionisation and GC-MS with electron impact ionisation, as well as semiquantitatively determined by the LC-MS technique. PG3 was found to be inherently biodegradable and it exhibits a strong poisonous effect on activated sludge after exceeding the threshold concentration (10 mg l(-1)). Metabolite accumulation onto the activated sludge is probably responsible for this poisonous effect. Probable biotransformation products of tripropylene glycol under the aerobic conditions include metabolites with a single terminal aldehyde or a ketone group and metabolites with two terminal aldehyde or ketone groups. Their concentration rises at the end of the OECD screening test.

Abstract  Dipropylene glycol (DG) has been considered safe to use as a solvent in perfumes and other cosmetics (1). Our recent case of allergic contact dermatitis from DG in a hand lotion (2) prompted this further study. Materials and Methods: We used standard (S) DG (synthesis grade purity >97%) from E. Merck (Darmstadt, Germany) and cosmetic grade (CG) DG (purity 96%) from our case (2). In a pilot study, 34 eczema patients were patch tested with either S or CG DG at 10%, 5%, 2% and 1% aq. When no reactions were seen, the standard series at Gentofte was supplemented with DG 10% aq., S and CG, for 7 months (25.1.94- 25.8.94). 503 consecutive eczema patients, 212 men and 291 women, were tested, patches being applied for 2 days, using Scanpor tape and Finn Chambers, and reactions being read at D2, D3 and 05-7. The original patient (2) was repatch tested with both S and CG DG at I% and 0.5% aq. Results: 6. 7% (34/503) of the patients reacted to at least 1 of S and CG DG (Table 1). There was l positive patch test reaction to S DG, the remaining reactions being either ?+, 5.1% (26/503), or IR, 1.4% (7/503) (no sex difference). 10 of those with ?+ reactions to DG were also tested with their own cosmetics and 2 reacted, l to mascara, skin tonic and eye shadow, and I to camomile liniment (DG contents not determined). The original patient (2) had + + and + + + reactions to CG DG, as well as to S DG, 0.5% and 1% aq. Discussion: DG is a mixture of 3 isomers (1), their distribution in the 2 grades used in this study differing as determined by GC/MS (2). The original patient (2) reacted to both grades and no difference was found between the frequency of reactions to the 2 grades in 503 consecutive eczema patients. Only 1 patient out of 503 (0.2%), however, had a definitely positive patch test reaction to DG, its clinical relevance not being established. Patch testing with other grades of DG used in cosmetics (I) might give different results, but at present, we consider contact allergy to dipropylene glycol to be rare in our study population.