Furniture Stripping Research Articles

Overexposure and Control of Methylene Chloride in a Furniture Stripping Operation

This inspection by the Occupational Safety and Health Administration (OSHA) reports on OSHA follow-up activity where employees were overexposed to methylene chloride.( 1 ) The employer operated a s...

Exposures to lead, metals, and wood dust during stripping and refinishing furniture.

The National Institute for Occupational Safety and Health (NIOSH) received a request for a Health Hazard Evaluation (HHE) from a management official at a furniture finishing company. The request concerned worker exposures to lead and other metals that may result from stripping and refinishing furniture. A survey was conducted to evaluate worker exposures in the furniture stripping shop for lead, other metals, and wood dust during typical wood stripping and refinishing operations.

Engineering controls for furniture strippers to meet the OSHA methylene chloride PEL.

This case study demonstrates how methylene chloride exposures during furniture stripping can be reduced to below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 25 ppm (as an 8-hour time-weighted average). Five surveys were conducted at one facility; the first four resulted in employee exposure geometric means from 39 to 332 ppm. For the fifth survey local exhaust ventilation was used at the stripping tank and the rinsing area, which together exhausted 138 m3/min (4860 ft3/min). Additional controls included providing adequate make-up air, adding paraffin wax to the stripping solution, raising the level of the stripping solution in the tank, and discussing good work practices with the employee. The employees' methylene chloride exposures during the fifth survey resulted in a geometric mean of 5.6 ppm with a 95% upper confidence limit of 8.3 ppm, which was found to be significantly lower than the OSHA PEL and the OSHA action level of 12.5 ppm. The cost of the ventilation system was $8900.

The impact of maintenance and design for ventilation systems.

Ventilation systems need to be designed to include access for cleaning and preventive maintenance. Without such access, the exhaust volume will deteriorate. Because of access difficulties and the many demands on their time, plant managers are sometimes errant in performing proper preventive maintenance. Three surveys measuring workers' exposures to methylene chloride were conducted at the same furniture stripping facility. A new ventilation system was installed for the first survey, resulting in an exhaust volume of 2900 cfm and worker exposure to methylene chloride of 59 ppm (geometric mean). Immediately after the first survey, the gasoline-powered fan was replaced by a smaller capacity electrically powered fan. Deterioration in the ventilation system was seen after seven years. Problems included clogged slots, paint chips and sawdust deposits in plenums, and a loose and frayed fan belt. The second survey indicated a reduction in exhaust volume to 1060 cfm and increased worker exposure to 330 ppm. With the smaller capacity fan still in place, the system was otherwise upgraded to allow for easier access and maintenance was performed. The third survey showed that the ventilation system performance was better (exhaust volume improved to 2080 cfm) and the worker exposures were reduced to 73 ppm. This study shows the benefits of designing for preventive maintenance and the necessity of keeping the ventilation systems clean.

Case study: control of methylene chloride exposures during furniture stripping.

Methylene chloride, a potential occupational carcinogen, is one of the principal solvents used for furniture stripping. Methylene chloride exposures among workers in furniture stripping operations have been found to be high. This article describes a furniture stripping operation at a sheltered workshop before and after the ventilation system was modified. Previous to ventilation system modifications, workers who were stripping furniture had exposures to methylene chloride ranging from 600 to 1150 ppm. These high exposures and an evaluation of the ventilation system prompted the design and installation of a modified ventilation system. Primary modifications included installing a local ventilation hood, decreasing the velocity of makeup air entering the stripping area, removing a contaminated charcoal adsorption bed and improving work practices. The modified system was arranged into three configurations that included a slot hood, a downdraft hood, and a combination slot and downdraft hood. The three configurations were evaluated over a three-day period, and it was found that they controlled the worker's personal exposures to methylene chloride while stripping to 28 ppm for the combination configuration, 30 ppm for the downdraft configuration, and 34 ppm for the slot configuration. Although the exposures are above the proposed Occupational Safety and Health Administration permissible exposure level of 25 ppm, these results show a substantial improvement over the existing ventilation system. The ventilation system described is applicable to other furniture stripping facilities if rinse area local ventilation is improved.

Case Study: Control of Methylene Chloride Exposures During Furniture Stripping

Methylene chloride, a potential occupational carcinogen, is one of the principal solvents used for furniture stripping. Methylene chloride exposures among workers in furniture stripping operations have been found to be high. This article describes a furniture stripping operation at a sheltered workshop before and after the ventilation system was modified. Previous to ventilation system modifications, workers who were stripping furniture had exposures to methylene chloride ranging from 600 to 1150 ppm. These high exposures and an evaluation of the ventilation system prompted the design and installation of a modified ventilation system. Primary modifications included installing a local ventilation hood, decreasing the velocity of makeup air entering the stripping area, removing a contaminated charcoal adsorption bed, and improving work practices. The modified system was arranged into three configurations that included a slot hood, a downdraft hood, and a combination slot and downdraft hood. The three configurations were evaluated over a three-day period, and it was found that they controlled the worker's personal exposures to methylene chloride while stripping to 28 ppm for the combination configuration, 30 ppm for the downdraft configuration, and 34 ppm for the slot configuration. Although the exposures are above the proposed Occupational Safety and Health Administration permissible exposure level of 25 ppm, these results show a substantial improvement over the existing ventilation system. The ventilation system described is applicable to other furniture stripping facilities if rinse area local ventilation is improved.

Control of Methylene Chloride—Furniture Stripping Dip Tank

Abstract The furniture stripping industry has an estimated 21,000 workers who are employed by approximately 4000 small businesses averaging slightly over five employees each. Previous worker exposure studies have documented time-weighted average exposures to methylene chloride in the furniture stripping industry ranging from 300 parts of methylene chloride per million parts of air (ppm) to over 2100 ppm. This article describes an evaluation of a local exhaust ventilation system designed by researchers from the National Institute for Occupational Safety and Health (NIOSH) for furniture stripping dip tanks that can be used to control methylene chloride exposures to workers. The dip tank process makes up approximately 10 percent of the furniture stripping industry. (Ventilation systems for the major process, the solution recycle method, have been previously evaluated by NIOSH researchers and the information has been published elsewhere.) The ventilation system described herein is a two-sided slot hood with a...

Exposure of Workers Engaged in Furniture Stripping to Methylene Chloride as Determined by Environmental and Biological Monitoring

Abstract In response to reports of adverse reproductive effects of exposure to methylene chloride, investigators from the National Institute for Occupational Safety and Health conducted an industrial hygiene survey of a cohort of 14 furniture strippers exposed to methylene chloride in five furniture stripping shops. Both environmental and biological monitoring of the workers were conducted. Personal time-weighted average (TWA) concentrations of methylene chloride were determined. Pre- and postshift alveolar breath samples were analyzed for carbon monoxide and methylene chloride. Postshift venous blood samples were analyzed for carboxyhemoglobin and methylene chloride. Methylene chloride TWA exposures of the workers ranged from 15 to 366 ppm, while exposures to other solvents were well below their respective evaluation criteria. The highest average exposures to methylene chloride by job category were strippers (191 ppm) followed by washers (145 ppm) and refinishers (31 ppm). Postexposure breath concentrations of methylene chloride ranged from 2.3 to 167 ppm, while blood concentrations ranged from 0.1 to 8.8 ppm. Linear regression analysis showed that the TWA methylene chloride exposure concentrations were quadratically correlated to postshift alveolar breath (r = 0.98) and blood concentrations (r = 0.87) of methylene chloride. This high degree of correlation between the biological and environmental concentrations suggested that the major route of exposure was inhalation. Serious problems with ventilation of sprayer-based furniture stripping operations were found. Deficiencies in work practices and personal protective equipment were also noted. Recommendations are made for reducing exposures to methylene chloride during furniture stripping.

Furniture Stripping Vapor Inhalation Fatalities: Two Case Studies

Abstract Two strikingly similar fatal accidents at furniture stripping workplaces were investigated to determine causes and recommend preventive measures. The investigations included air sampling for solvent vapor concentrations, observations at the accident scenes, extensive interviews with co-workers and acquaintances of the victims, a review of material safety data sheets and other documentation, and a consideration of the medical records including autopsies. Both employers were cited under Michigan OSHA standards for exposing the victims to an injurious mixture concentration of solvent vapors. The stripping liquids were composed of methylene chloride (65–85%), methanol (6–12%), and other additives. Both the methanol and the methylene chloride posed a significant vapor inhalation hazard. Highly toxic, oxygen-deficient atmospheres existed within the unventilated tanks; however, in the working area outside the tanks, nonlethal levels were found. Both victims were young males who were found with their upp...