• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.7 no.2
• /
• pp.171-180
• /
• 1997

The objectives of this study were both 10 discuss the sampling method for airborne metalworking fluids(MWF)' mist and 10 suggest measures to minimize worker's exposure to carcinogen contained in metalworking fluids. In order to measure airborne MWF mist, it seems to be appropriate to use NIOSH Method #0500(filler weight) rather than NIOSH Method # 5026(analysis by FTIR). Because MWF mist on PVC filter evaporated and migrated during sampling, worker's exposure to MWF could be underestimated. So, when evaluating worker's exposure to MWF mist, other environmental conditions also must be considered. Enclosure and local exhaust ventilation system seems to he the most effective measure and must be constructed with process facility. In order to control worker exposure to carcinogens contained in MWF, distillation type and condition for crude oil, PAH concentration in MWF, and viscosity index of MWF must legally be described.

• Analytical Science and Technology
• /
• v.14 no.5
• /
• pp.451-457
• /
• 2001

Because liquids with high molecular weight such as mineral oil have low vapor pressure at room temperature, it is generally thought to be difficult to lose them to evaporation. However, when they are dispersed into air in small droplets during application in machining processes, their surface area becomes considerably higher. To determine the potential for metalworking fluids (MWF) filter losses, MWF mist was generated and collected on polyvinyl chloride (PVC) filters in test chamber. After collected MWF was exposed to clean air during designated period (range 10~240 minutes) and the filters were desiccated, losses were evaluated. As duration of clean air passing through PVC filter increased, loss of MWF gradually increased. MWF lost after 10 minutes ranged form 12.4 % to 21.8 % of the original loading mass, on average 53.3 % of the total loss. These results indicate that significant mass of MWF collected on PVC filters can be lost at the beginning of air sampling. Loss of MWF collected on PVC filter also occurred during desiccation without active airflow. In multiple regression to identify which factors influence the loss of MWF collected on PVC filter, both duration of air passing through PVC filter and MWF age (fresh vs. used) were significant predictor (p=0.0001). Therefore, workers' exposure to MWF measured method 0500, may underestimate true concentration. Further study is needed to develop a new method to quantify the workers' exposure to airborne MWF mist accurately.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.8 no.2
• /
• pp.186-195
• /
• 1998

The objective of this study was to determine if MWF(metalworking fluids) mass sampled on PVC filter lose during flowing airstream and desiccating and to present direction to correct the underestimated MWF mass. Flowing airstream caused MWF sampled on PVC filter to be breakthrough and lost. Loss of MWF on PVC filter increased in proportion to time of flowing airstream. Meanwhile, loss of MWF was observed during desiccating without flowing airstream. Vapor pressure of MWF is so low that it would not normally be thought to evaporate. However, MWF mist sampled on PVC filter has so great a surface area that loss by flowing airstream and evaporation can be appreciable. Loss between fresh and used MWF was also different. Those study results mean that NIOSH method(#0500 method) to take airborne MWF mist with PVC filter is not valid. Media to sample airborne MWF accurately still have not been introduced. It seems to be needed to estimate how much MWF on PVC filter may be lost during sampling. Regression model between sampling time including 1 day desiccating and total loss of MWF was "Total loss(%)=18.4%+0.06 sampling time(p=0.000, r2=49.6%)". This model help correct MWF lost when one measures airborne MWF using NIOSH # 0500 method.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2005.06a
• /
• pp.326-329
• /
• 2005

A worker who grinded the inner parts of camshafts for automobile engines using water-soluble metalworking fluid (MWF) for 14 years was diagnosed with sinusitis. We postulated that the outbreak of sinusitis could be associated with exposure to microbes contaminated in water-soluble MWF during the grinding operation. To suggest responsible agents for this outbreak, quantitative exposure assessment for chemical and biological agents and prevalence of work-related respiratory symptoms by questionnaire were studied. The exposure ranges of MWF mist (0.59 $mg/m^3$to 2.12 $mg/m^3$) measured during grinding exceeded 0.5 $mg/m^3$ of the recommended exposure limit (REL). Grinder's exposures to bacteria, fungi and endotoxins were also generally higher than not only the proposed standards, but also those reported by several studies to identify the cause of respiratory effects. Statistical test indicated that the prevalence rate of reported symptoms related to nasal cavities showed no significant differences among the operations. Evaluation on grinding operation characteristics and quantitative exposure assessment indicated that repeated exposure to MWF mist including microbes contaminated from the use of water-soluble MWF may cause respiratory diseases like sinusitis or at least increase susceptibility to the development of sinusitis

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.24 no.3
• /
• pp.300-309
• /
• 2014

Objectives: The objective of this study is to evaluate microbial exposure hazards in the metal-working fluids(MWF) handling industry. Methods: Air quality parameters(airborne bacteria, fungi, endotoxin and oil mist) and bulk MWF in storage tanks were evaluated at 54 points at nine sites in South Korea. Results: The geometric means(GM) of culturable airborne bacteria, fungi, endotoxin and oil mist concentration were $133CFU/m^3$(n=376, range $7{\sim}6,510CFU/m^3$), $159CFU/m^3$(n=381, range $7{\sim}8,469CFU/m^3$), $8.06EU/m^3$(n=103, range $0.34{\sim}280.4EU/m^3$) and $0.20mg/m^3$(n=104, range $0.01{\sim}2.87mg/m^3$), respectively. The ratio of indoor to outdoor concentration was 2.7 for bacteria, 6.1 for endotoxin, and 4.8 for oil mist. Even though average airborne bacteria concentration did not exceed recommended exposure limits($1,000CFU/m^3$), MWF in the storage tanks was highly contaminated with bacteria(arithmetic mean $2.1{\times}10^6CFU/ml$) and exceeded recommended bacteria limits($10^5CFU/ml$). Conclusions: It is necessary for MWF handling workplaces to conduct periodical biohazard inspection of MWF storage tanks. Additionally, further research may be necessary to establish biological occupational exposure limits.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.1
• /
• pp.50-62
• /
• 2003

Exposure to metalworking fluids (MWFs) has significantly been associated with cancer developed in multi-organs, respiratory diseases and skin diseases. Several carcinogens to humans or animals are contained in MWFs. They have been reported to be mineral oils, polynuclear aromatic hydrocarbons (PAHs), formaldehyde and N-nitrosodiethanolamine (NDELA). The great hazards of MWF have forced the advanced country including United States to regulate carcinogens contained in MWF. In 2001, American Conference of Governmental Industrial Hygienists (ACGIHs) regarded MWF mist as suspected carcinogen to human (A2) and added it to “Notice of Intended Change (NIC)” list of 2001. In spite of the fact that much MWF has widely been used in many industries using machines, Korea has no legal actions for management of MWF. What is worse, even toxicity such as Carcinogenicity has not been reported. KS (Korean Standards) lists 7 advices of MWF but it does net state the hazards to health. It is very hard to control or minimize worker's exposure to MWF containing many carcinogens. Prier to the introduction of MWF to workplace, it is the most effective measure to regulate carcinogens below a certain level. Regulation on the content of PAH seems to be necessary because less amount of PAH in mineral oils improves the quality of MWF. Also, addition of nitrosating groups to MWF should be prohibited to minimize worker's exposure to NDELA. Employers and manufacturers should indicate the Carcinogenicity of all carcinogens in MWFs in Material Safety Data Sheets (MSDS) in order fer workers to recognize Carcinogenicity. Legal actions have to be taken to protect workers from health hazards due to exposure to MWF by further investigation on MWF.

• Safety and Health at Work
• /
• v.3 no.1
• /
• pp.1-10
• /
• 2012

The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/$m^3$, short-term exposure limit ; 15 mg/$m^3$) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/$m^3$ ) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.3
• /
• pp.166-175
• /
• 2005

Health effects associated with metal working fluid (MWF) exposures include dermatitis, respiratory disease, hypersensitive pneumonitis, and asthma. Frequently, occupational exposures to MWFs are controlled by ventilating an enclosure with an air cleaning unit that includes a fan preceded by various kinds of filtration. There are several kinds of air cleaning units used in machining centers. But the associated troubles have hindered from efficiently using these devices. The main problem is the relatively short period of filter replacement. The reason is that the air cleaning units usually do not have the de-oiling systems, thus leading the earlier clogging of filters and reducing the flow rate of hood. Thus, the first stage of study was conducted to overcome this problem by developing the new oil mist collector equipped with the easy de-oiling system. The principle of de-oiling is that the centrifugal force generated by spinning the drum covered by filter fabric separates oils from the filter fabric. It would be very similar to the spin-dry laundry. By adopting this de-oiling technique, the problems associated with the conventional oil mist collectors could be solved. Several tests/analyses were performed to make the lab-scale oil mist collector. The collection efficiencies and the de-oiling efficiencies of commercially available filter fabrics were tested. Subsequently, the endurance test were conducted by observing SEM photos of filter fabrics and measuring tensile strength/expansion coefficient after spinning the filter drum for 20 minutes at the different rotation speeds. By doing these experiments, the most appropriate filter fabric and rotation speed/duration were selected. Finally, the new oil mist collector was designed. In the near future, this device must be tested in the real machining center.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2001.11a
• /
• pp.293-294
• /
• 2001

자동차 엔진을 구성하는 소재 가공시에 냉각, 절삭용구와 가공표면의 용접현장(welding), 고온에서의 마모방지와 잔열로 인한 비틀림(distortion) 방지 등을 목적으로 사용되는 수용성(soluble) MWFs (Metalworking Fluids)의 기능에 필요한 구성물질인 기유(base oil)와 첨가제(additive)가 건강상 장해를 유발한다고 알려지고 있다(김신범, 1997). 하지만 수용성 MWFs를 사용하여 소재를 가공하는 산업현장에서는 MWFs 미스트 발생제어를 공정 상부에 외부식 후드를 국소적으로 설치하는 것이 일반적인 방법이다(Fig.2). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.531-532
• /
• 2003

공작기계 가동시 윤활과 냉각 등의 목적으로 다양한 종류의 금속가공유 (MWFs : 절삭유, 윤활유, 방청유 둥)를 사용하고 있다. MWFs에는 포름알데히드, 니트로스아민, 염화파라핀 등의 발암물질이 포함되어 있는 것으로 알려져 있어 작업자 건강보호를 위해 효율적인 환기가 요구되고 있다. 현장에서 가장 많이 사용하고 있는 포켓 필터형 오일미스트 콜렉터는 제진 장치가 없기 때문에 필터 표면에 한번 부착된 오일 미스트와 먼지가 떨어지지 않기 때문에 일정시간 후 필터 표면에 막힘 현상이 발생한다. 필터 표면이 막히면 차압 증가와 함께 송풍량이 감소하기 때문에 미스트 제거 효율이 크게 저하되고, 결과적으로 오일미스트의 환기 효율이 크게 감소된다.(중략)