Assessment of Methylene Chloride-Related Fatalities in the United States, 1980-2018.

Importance: Methylene chloride is a halogenated organic solvent widely used in paint strippers, cleaners, adhesives, and sealants. Despite label warnings and occupational standards, methylene chloride-related fatalities continue to occur in the United States. Objective: To identify and analyze methylene chloride-related fatalities in the US. Design, Setting, and Participants: For this case series, we conducted systematic searches of sources, including PubMed and government databases, for unintentional fatalities in the US that were associated with exposure to methylene chloride or products containing methylene chloride between 1980 and 2018. We reviewed all available information, including inspection reports, autopsy reports, and medical records; data analyses were conducted from August 2018 to August 2020. Cases were categorized as those occurring in the home (consumer deaths) or at work (occupational deaths). Exposures: Methylene chloride or products containing methylene chloride. Main Outcomes and Measures: To determine characteristics of the methylene chloride-related fatalities, we recorded demographic information; the setting; circumstances, including information on safety measures used, if available; and products used. Where medical records were available, we recorded toxicology results and autopsy findings. We also obtained data about nonfatal methylene chloride cases from the American Association of Poison Control Centers. Results: From 1980 to 2018, 85 methylene chloride-related fatalities were identified in the US, including 74 (87%) in occupational settings; of those who died, 75 (94%) were men, and for the 70 cases with available information, the median (interquartile range) age of the decedents was 31 (24-46) years. Paint strippers were the most common products involved in methylene chloride-related fatalities (n = 60). The proportion of occupational fatalities related to paint stripping increased from 22 (55%) before 2000 to 30 (88%) after 2000. Similarly, occupational fatalities associated with bathtub or paint stripping in bathrooms increased from 2 (5%) before 2000 to 21 (62%) after 2000. From 1985 to 2017, the American Association of Poison Control Centers documented 37 201 nonfatal methylene chloride cases, with a decrease in the annual number of cases starting in the late 1990s. Conclusions and Relevance: Results of this case series demonstrated that despite regulations to address the toxic effects of methylene chloride use for consumers and workers, there are continuing fatalities in the US, particularly in occupational settings. Prevention of fatalities associated with methylene chloride exposure should emphasize the use of safer substitutes, rather than hazard warnings or reliance on personal protective equipment.

Occupational solvent exposure and adult chronic lymphocytic leukemia: No risk in a population-based case-control study in four Nordic countries.

The aim of this study was to assess the effect of occupational solvent exposure on the risk of adult chronic lymphocytic leukemia (CLL). The current case-control study was nested in the Nordic Occupational Cancer Study (NOCCA) cohort. 20,615 CLL cases diagnosed in 1961-2005 in Finland, Iceland, Norway, and Sweden, and 103,075 population-based controls matched by year of birth, sex, and country were included. Occupational histories for cases and controls were obtained from census records in 1960, 1970, 1980/1981, and 1990. Exposure to selected solvents was estimated by using the NOCCA job-exposure matrix (NOCCA-JEM). Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by using conditional logistic regression models. Overall, nonsignificant CLL risk elevations were observed for methylene chloride, perchloroethylene, and 1,1,1-trichloroethane. Compared to unexposed, significantly increased risks were observed for cumulative perchloroethylene exposure ≤13.3 ppm-years (OR = 1.85, 95% CI 1.16-2.96) and average life-time perchloroethylene exposure ≤2.5 ppm (1.61, 95% CI 1.01-2.56) among women, and cumulative methylene chloride exposure ≤12.5 ppm-years (OR = 1.19, 95% CI 1.01-1.41) and 12.5-74.8 ppm-years (OR = 1.23, 95% CI 1.01-1.51) among men in an analysis with 5 years lag-time, though without dose-response pattern. Decreased CLL risk was observed for aliphatic and alicyclic hydrocarbon solvents and toluene. This study did not support associations for solvent exposure and CLL. Observed weak associations for methylene chloride, perchloroethylene, 1,1,1-trichloroethane exposures, aliphatic and alicyclic hydrocarbons and toluene were not consistent across sexes, and showed no gradient with amount of exposure.

Evaluation of three physiologically based pharmacokinetic (PBPK) modeling tools for emergency risk assessment after acute dichloromethane exposure.

INTRODUCTION: Physiologically based pharmacokinetic (PBPK) models may be useful in emergency risk assessment, after acute exposure to chemicals, such as dichloromethane (DCM). We evaluated the applicability of three PBPK models for human risk assessment following a single exposure to DCM: one model is specifically developed for DCM (Bos) and the two others are semi-generic ones (Mumtaz and Jongeneelen). MATERIALS AND METHODS: We assessed the accuracy of the models' predictions by simulating exposure data from a previous healthy volunteer study, in which six subjects had been exposed to DCM for 1h. The time-course of both the blood DCM concentration and percentage of carboxyhemoglobin (HbCO) were simulated. RESULTS: With all models, the shape of the simulated time course resembled the shape of the experimental data. For the end of the exposure, the predicted DCM blood concentration ranged between 1.52-4.19mg/L with the Bos model, 1.42-4.04mg/L with the Mumtaz model, and 1.81-4.31mg/L with the Jongeneelen model compared to 0.27-5.44mg/L in the experimental data. % HbCO could be predicted only with the Bos model. The maximum predicted % HbCO ranged between 3.1 and 4.2% compared to 0.4-2.3% in the experimental data. The % HbCO predictions were more in line with the experimental data after adjustment of the Bos model for the endogenous HbCO levels. CONCLUSIONS: The Bos Mumtaz and Jongeneelen PBPK models were able to simulate experimental DCM blood concentrations reasonably well. The Bos model appears to be useful for calculating HbCO concentrations in emergency risk assessment.

Bilateral hearing loss after dichloromethane poisoning: a case report.

Dichloromethane is a widely used organic solvent. Occupational exposure to dichloromethane is frequent and can result in both acute and chronic toxicity, affecting mostly the central nervous system, directly or through its metabolite, carbon monoxide. The effects of dichloromethane on the peripheral nervous system are debated. Here we report the case of a 37-year-old woman who was accidentally exposed to dichloromethane. In the days following the incident she experienced bilateral hypoacusis. Hearing loss regressed after 25 days treatment with hyperbaric oxygen. This is the first report of sudden hearing loss after acute exposure to dichloromethane, suggesting a possible toxic effect of this solvent on the auditory system.

Fatalities due to dichloromethane in paint strippers: a continuing problem.

BACKGROUND: Exposure to dichloromethane (DCM or methylene chloride - CH2 Cl2 ) in paint strippers continues to be an avoidable source of morbidity and mortality. DCM has been under regulatory scrutiny by occupational and consumer product agencies since the identification of its carcinogenicity in the mid-1980s. METHODS: We investigated two independent workplace incidents that resulted in three cases of DCM intoxication from paint stripper use. RESULTS: Each incident investigated resulted in a fatality. A third worker suffered obtundation requiring hospitalization and intubation. CONCLUSIONS: The continued occurrence of fatalities and other serious injuries due to DCM-containing paint strippers in the United States calls for a re-evaluation of existing regulatory strategies.

A case of methylene chloride poisoning due to ingestion of home-distilled alcohol and potential new treatment with ethanol infusion.

We describe a case of a 51-year-old man who ingested methylene chloride and presented with the classical clinical features. He developed an acute abdomen that required repeated laparotomy. The effect of an ethanol infusion on carboxyhaemoglobin concentrations in this case was also of interest and could potentially be a new treatment modality.

Fatal exposure to methylene chloride among bathtub refinishers - United States, 2000-2011.

In 2010, the Michigan Fatality Assessment and Control Evaluation program conducted an investigation into the death of a bathtub refinisher who used a methylene chloride-based paint stripping product marketed for use in aircraft maintenance. The program identified two earlier, similar deaths in Michigan. Program staff members notified CDC's National Institute for Occupational Safety and Health (NIOSH), which in turn notified the Occupational Safety and Health Administration (OSHA). In addition to the three deaths, OSHA identified 10 other bathtub refinisher fatalities associated with methylene chloride stripping agents that had been investigated in nine states during 2000-2011. Each death occurred in a residential bathroom with inadequate ventilation. Protective equipment, including a respirator, either was not used or was inadequate to protect against methylene chloride vapor, which has been recognized as potentially fatal to furniture strippers and factory workers but has not been reported previously as a cause of death among bathtub refinishers. Worker safety agencies, public health agencies, methylene chloride-based stripper manufacturers, and trade organizations should communicate the extreme hazards of using methylene chloride-based stripping products in bathtub refinishing to employers, workers, and consumers. Employers should strongly consider alternative methods of bathtub stripping and always ensure worker safety protections that reduce the risk for health hazards to acceptable levels. Employers choosing to use methylene chloride-based stripping products must comply with OSHA's standard to limit methylene chloride exposures to safe levels.

A case of acute toxic hepatitis after suicidal chloroform and dichloromethane ingestion.

Chloroform and dichloromethane are halogenated hydrocarbons that have been used as a potent anesthetic agent or a general industrial solvent. Short-term exposure to chloroform anesthesia and long-term exposure to chloroform and dichloromethane in workplaces can produce adverse health effects, such as hepatitis, cardiac arrhythmia, and carbon monoxide intoxication. Most of the related reports, however, involve the inhalation of such substances by humans. Limited reports are available regarding the adverse clinical effects of these substances in the case of a person's immediate ingestion of them. A 23-year-old man with an altered mental status after attempting suicide through the oral ingestion of unknown chemicals was brought to the emergency department (ED). We identified that the patient was poisoned with chloroform and dichloromethane by analysis of contents of the suspected chemicals in the bottle through gas chromatography. Abnormal liver enzymes were noted on postingestion day 2, and jaundice occurred on postingestion day 3. The radiologic findings from computed tomographic (CT) scanning showed severe fatty infiltration of the liver parenchyma. The patient received supportive cares and was restored to health from hepatic dysfunction and was discharged without complications after 2 weeks of admission.

Severe optic neuropathy caused by dichloromethane inhalation.

PURPOSE: In this paper, we report a case of severe optic neuropathy caused by dichloromethane inhalation. CASE: A 65-year-old man fell unconsciousness while cleaning a dichloromethane tank containing a small amount of dichloromethane (purity greater than 99%) and was transported to the emergency department of our hospital, after which he was treated with hyperbaric oxygen therapy. After 1 month, narrowing of the visual field in both eyes was noted and the patient was referred to our department for additional examinations. Visual acuity was 0.3 in both eyes, which demonstrated normal reactions to light, while the critical flicker frequency (CFF) values were 30 and 25 Hz in the right and left eye, respectively. There were no abnormal findings shown in slit-lamp and fundus examinations, except for a mild cataract. Concentric contractions of the visual field by 10 degrees in both eyes were shown by a Goldmann perimetry examination, while an electroretinogram (ERG) and visual evoked cortical potential (VECP) examination exhibited nearly normal results. We diagnosed the condition as optic neuropathy caused by organic solvent poisoning, based on the decreased visual acuity, decreased CFF values, and visual-field narrowing. Although the patient was treated with vitamin B(12), visual disturbance, optic nerve atrophy, and results of VECP examinations worsened in both eyes, whereas ERG examination results were normal. CONCLUSIONS: Based on our findings, we considered that the central nervous system, including the optic nerve, was more severely damaged than the retina due to the normal findings in the ocular fundus and ERG examinations. Since dichloromethane produces carbon monoxide when catabolized in the liver, carbon monoxide toxicity together with the direct toxic effect of dichloromethane were considered to contribute to optic neuropathy in this case. The outcome for the present patient was poor.

Repercusiones multiorgánicas de la inhalación de alcohol isopropílico y cloruro de metileno como substancias de abuso / Multiorganic involvement after inhalation of isopropyl alcohol and dichloromethane as a form of substance abuse

En España el consumo de substancias de abuso está muy extendido. Entre las drogas ilegales destaca, en el momento actual, la prevalencia de consumidores de cannabis, derivados anfetamínicos y cocaína. Los inhalables volátiles, como las colas, pegamentos, gasolina y disolventes, representan otra forma de consumo de drogas, pero que está poco arraigada en nuestro medio. Se presenta el caso de una mujer snifadora crónica de una laca para el pelo, que contenía alcohol isopropílico y cloruro de metileno, y que fue remitida al Servicio de Urgencias por una sobredosis. Durante el ingreso se constataron alteraciones en las estructuras subcorticales de los lóbulos frontales, en la biología hepática y renal y en las pruebas funcionales respiratorias. También se objetivó una disfunción de la citocromooxidasa mitocondrial. La paciente evolucionó favorablemente

Substance abuse is widespread in Spain. Currently, the consumption of cannabis, amphetamine derivatives and cocaine is notable. Volatile inhaled substances such as glue, petrol and solvents are forms of substance abuse whose use in Spain is comparatively infrequent. We present the case of a female chronic sniffer of hair lacquer, containing isopropyl alcohol and dichloromethane, who was admitted to the emergency department after an overdose. Tests revealed alterations in the subcortical structures of the frontal lobes, hepatic and renal abnormalities, and deficits in respiratory function tests, all of which were attributed to chronic solvent abuse. Mitochondrial cytochrome oxidase dysfunction was also observed

Acute methylene chloride intoxication--a case report on domestic poisoning.

Acute intoxication by methylene chloride has primarily been reported from occupational settings. However, it may occur through domestic exposure, by the use of aerosol sprays, degreasers and paint removers. We describe an unusual case of an accidental domestic methylene chloride intoxication through the use of aerosol spray, resulting in an HbCO of 30%.

Fatal intoxication due to excessive dichloromethane inhalation.

A 22-year-old white male was found dead at his working place in a car lacquering company. He had removed lacquer residues by using a solvent containing dicloromethane (DCM) without using a gas mask. Pathology revealed signs of asphyxiation with obvious petechial bleedings and expressed microthrombosis of the pulmonary arteries. Toxicological analysis showed excessive concentrations of DCM which are inhaled due to exposure of extreme air concentrations.

Accidental dichloromethane fatality: a case report.

A case of accidental dichloromethane poisoning by inhalation is presented. It is of interest that carboxyhemoglobin levels were within the normal range, suggesting that the narcosis and respiratory depression were due to the direct effect of DCM on the central nervous system. The accidental death was attributed to improper ventilation of vapors in the working area.

Postmortem absorption of dichloromethane: a case study and animal experiments.

A case of accidental death after occupational exposure to an atmosphere containing dichloromethane (DCM) is reported. The concentrations of DCM in the blood and tissues of a 40-year-old man who died while observing an industrial washing machine filled with DCM vapour were blood 1660 mg/l, urine 247 mg/l, brain 87 mg/kg, heart muscle 199 mg/kg and lungs 103 mg/kg which are 3-7 times higher than previously reported fatal levels. The body was left undiscovered in the machine filled with DCM vapour for about 20 h. The present study was designed to determine whether all the DCM detected in the tissues and body fluids had been inhaled while alive using rats as the experimental model. The concentrations of DCM in the tissues and body fluids of a rat that died from DCM poisoning and was left for 20 h in a box containing DCM vapour were the same as those in the tissues and body fluids of a rat that had died from an injected overdose of barbiturates and had then been placed in the DCM box in a similar manner. Moreover, the concentrations of DCM in the tissues and body fluids of the carcasses that were exposed to the DCM vapour increased gradually throughout the period of exposure. These findings imply that DCM is able to penetrate the tissues and body fluids of rat carcasses through a route other than inhalation such as through the skin.