Solution Summary: Portable Vacuum Fume Collectors with HEPA Filtration

A portable vacuum fume collector with HEPA filtration is a local exhaust ventilation unit that captures contaminants near the source.

Description:

A portable vacuum fume collector with HEPA (High Efficiency Particle Air) filtration is an engineering control that can reduce exposure to welding fumes, particles and dust. Portable vacuum fume collectors use a motor and fan to draw air and contaminants from the point of generation, through a flexible arm or duct and into the unit. The fumes and particles are then collected on a filter, reducing the concentration in the worker's breathing zone. These units have HEPA (high efficiency particulate air) filters to provide high collection efficiency of hazardous particles.

A welding fume capture and control system with HEPA filtration may be necessary to meet occupational exposure limits. HEPA filters capture 99.97% of the most penetrating particles but require pre-filters to extend the life of these denser filters, which are more expensive than other filters. Portable welding fume control systems also address the constant mobility of welders on construction sites. A welding ventilation bench hood is the most effective way to remove the hazardous fumes, but portable fume extractors provide a solution where semi-permanent fume hoods are not feasible.

Sentry Air Systems Model 300 Welding Fume Extractor

Power requirements: 115 volts, 2 amps
Approximate Weight: 45 pounds (depends on filters and options)
Filtration Options: HEPA (99.97% at 0.3 µm diameter), 95% efficient at 0.5 µm, charcoal, and specialty chemical, pre-filter
Air Flow Rate: 350 cubic feet per minute
Air flow rate is adjustable down to 50 cubic feet per minute
Hose Dimensions: 68 inches long, 5-inch diameter
220-volt model is available but does not come with a variable speed fan
Fire-retardant flex hose
Sound Pressure Level: approximately 61 to 66 A-weighted decibels (dBA) at 3 feet (90 dBA is OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Sentry Air Systems 400 Series Portable Fume Extractors

Model	SS-400-PFS	SS-400-FSD	SS-400-FSQ
Fume Extraction Arms	1	2	4
Maximum Air Flow Rate per Arm (cfm)	700	350	175
Hose Diameter (inches)	6	5	4
Hose Length (inches)	72	48	48

Power requirements: 115 volts, 2.5 amps
Approximate Weight: 75 pounds (depends on filters and options)
Filtration Options: HEPA, 95% efficient at 0.5 µm, charcoal, and specialty chemical, pre-filter
Air flow rate is adjustable down to 50 cubic feet per minute
220-volt model is available but does not come with a variable speed fan
Fire-retardant flex hose
Sound Pressure Level: approximately 60 A-weighted decibels (dBA) at 3 feet (90 dBA is OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Sentry Air Systems 450 Series Portable Fume Extractors

Model	SS-450-PFS	SS-450-FSD	SS-450-FSQ
Fume Extraction Arms	1	2	4
Maximum Air Flow Rate per Arm (cfm)	950	475	235
Hose Diameter (inches)	6	5	4
Hose Length (inches)	72	48	48

Power requirements: 115 volts, 10.7 amps
Approximate Weight: 85 pounds (depends on filters and options)
Filtration Options: HEPA, 95% efficient at 0.5 µm, charcoal, and specialty chemical, pre-filter
Air flow rate is adjustable down to 50 cubic feet per minute
220-volt model is available but does not come with a variable speed fan
Fire-retardant flex hose
Sound Pressure Level: approximately 72 A-weighted decibels (dBA) at 3 feet (90 dBA is OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Lincoln Electric Miniflex Portable Fume Extractor

(Photo courtesy of Lincoln Electric)

Power requirements: 115 volts, 15 amps
Weight: 38 pounds
Filtration: pre-filter, pre-separator, fine, HEPA (optional activated carbon filter)
Air Flow Rate: 94 or 134 cubic feet per minute
Hose Dimensions: 8 feet long, 1-3/4 inch diameter
Automatic start/stop capability, based on welding current, extends motor life
Sound Pressure Level: less than 70 A-weighted decibels (dBA) (90 dBA is OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Trion Air Boss One Man Portable HEPA Air Cleaner

Power requirements: 115 volts, 14 amps
Shipping Weight: 45 pounds
Filtration: spark trap, pre-filter, HEPA
Air Flow Rate: 220 cubic feet per minute
Hose Length: 10 feet
Sound Pressure Level: 85 A-weighted decibels (dBA) at 5 feet (90 dBA is OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

Enviroflex International, Inc. Portable Welding Smoke Extractors

Model	ESE102A	ESE202A	ESE102A-HV	ESE202A-HV
Maximum Air Flow Rate per Arm (cfm)	80	160	105	210
Motors	1	2	1	2
Power Requirements	120 volts, 6.5 amps	120 volts, 13 amps	120 volts, 8.5 amps	120 volts, 17 amps
Weight (pounds)	39	43	40	45

Filtration: pre-filter, HEPA, and optional carbon filter for odors and some gases
Hose Dimensions: 15 feet long, 1-3/4 inch diameter (25 and 50-foot hoses are available)
Nozzles: 3-inch cone, 3-inch cone with 1 foot of duct, 8-inch slot with 1 foot of duct (all with a magnetic base)
220 volt motors are available

Risks Addressed:

Welding generates fumes that can expose workers to manganese, iron, nickel, hexavalent chromium, and other elements found in the base metal, filler rod and coatings. These metals have relatively low occupational exposure limits and exposure can lead to serious health effects including lung cancer, Parkinson-like symptoms known as “manganism,” and neurological effects.

In a study of production welders and non-welders at a large manufacturing facility, production welders were found to have eight times greater welding fume metal exposures than non-welders 474 μg/m³to 60 μg/m³ (p=0.001) (Schoonover, 2010).

Meeker et al (2007) cite several sources that indicate manganese exposures among welders in construction range from 0.01 to 2.0 mg/m³ and often exceed occupational exposure limits. Meeker et al (2010) analyzed three sets of hexavalent chromium exposure data collected during welding and found that approximately 12 percent of the 348 exposures were above the OSHA PEL (5 μg/m³).

Occupational Exposure Limits for Fumes Associated with Welding

Metal	ACGIH TLV (mg/m³)	NIOSH REL (mg/m³)	OSHA PEL (mg/m³)
Manganese, elemental and inorganic compounds	0.02 (respirable) 0.1 (inhalable)	1	5 (as ceiling)
Hexavalent chromium, Cr (VI)	0.01 (insoluble)	0.001	0.005
Nickel	1.5 (inhalable)	0.015	1.0
Iron oxide	5 (respirable)	5	10

Employees exposed to Cr (VI) face an increased risk of significant health effects. The health effects cited by OSHA that are associated with Cr (VI) include lung cancer, asthma, nasal septum ulcerations and perforations, skin ulcerations (“chrome holes”), and allergic and irritant contact dermatitis.

NIOSH states that “Recent studies indicate neurological and neurobehavioral deficits may occur when workers are exposed to low levels of manganese (<0.2 mg/m³) in welding fumes. These effects include changes in mood and short-term memory, altered reaction time, and reduced hand-eye coordination.”

OSHA states that welding, cutting or heating performed in an enclosed space on metal coated with lead-bearing paint requires employers to provide local exhaust ventilation or protect employees with airline respirators.

How Risks are Reduced:

Portable vacuum fume extractors with HEPA filtration are used mainly for source capture of welding smoke and fumes. These units use a motor and fan to draw air and contaminants from the point of generation, through a flexible arm or duct and into the unit. The fumes and particles are then collected on a high efficiency filter, reducing the concentration in the worker's breathing zone. As long as the fumes are removed before they are inhaled, the hazard is reduced.

Using fume collectors will visibly remove particulate matter, but the extent that it reduces the small, respirable particles is significant. Although exposure is not reduced to zero, substantial reduction is documented. This is dependent on the amount of air flow through the machine, the distance welding occurs from the machine inlet, how effectively it filters particles in the air, the nature and amount of work and the extent to which workers are exposed to particles that are not captured. While there is little published sampling data on these specific tools, evidence indicates exposure to respirable metal particles can be significantly reduced through the use of fume extraction methods.

Mike Flynn and Pam Susi analyzed 30 years of welding sampling results from OSHA compliance inspections that included 100,000 measurements collected on 30,000 welders from 1978 to 2008. The results indicated that heavy construction and structural steel erection had elevated risks of exposures over the TLV for manganese. Mean values for lead, cadmium, copper, zinc, and hexavalent chrome were over the corresponding OSHA PEL (2013 AIHA conference presentation).

Meeker et al (2007) describe a study of the effectiveness of the Lincoln Electric Miniflex Portable Fume Extractor. Use of the Miniflex resulted in a 75 percent reduction in manganese exposures when used in an experimental setting and a 53 percent reduction when used in a field setting. Meeker et al (2010) report mean breathing zone Cr (VI) concentrations were reduced by 55 percent and to less than the REL when LEV was used in an experimental setting, compared to no LEV use.

In a limited study paid for by Sentry Air Systems, Inc., RF Adams & Associates, Inc. measured a 97 percent reduction in a welder’s exposure to hexavalent chromium while using a Sentry fume extractor (Model 300-WFE) during MIG welding of stainless steel.

An unpublished report (Meeker & Susi, 2013) on the evaluation of the Trion Air Boss One Man Portable HEPA Air Cleaner indicates that it may be effective in reducing hexavalent chromium exposures during welding of stainless steel. Manganese exposures were higher when the air cleaner was not used but the difference was not statistically significant for manganese, nickel or iron concentrations while welding.

A different report looked at the effectiveness of portable and mobile fume extractors during electric arc welding in India. Results indicate that the breathing zone concentration of manganese was reduced from 22.16 (standard deviation = 20.90) μg/m³ to 8.25 (standard deviation = 4.5) μg/m³ through the use of a portable 110-pound (50 kilograms) local exhaust ventilation (LEV) system. This corresponds to an average reduction of manganese concentration in the welder’s breathing zone of 63 percent. Use of mobile 330-pound (150 kilograms) LEV unit reduced the concentration of manganese in the welder’s breathing zone from 70.06 (standard deviation = 37.38) μg/m³ to 8.29 (standard deviation = 1.76) μg/m³. This corresponds to an average of an 88 percent reduction in manganese exposure (Zaidi, 2004).

Additional Considerations:

Ventilation for construction tools is often misunderstood. There are additional conditions and practices that can improve the performance of fume collectors and reduce welding fume exposure:

Keep your head out of the welding fume plume.
Position the fume collector so that it is drawing welding fumes and gases away from you and be sure that partitions or other structures do not block cross ventilation.
Position the vacuum hood or shroud as close to the point of fume generation as possible to improve effectiveness.
Wear a NIOSH-approved respirator until exposures are known or if adequate ventilation can't be provided. An industrial hygienist should evaluate each welding process you perform to determine the need for a respirator.
Monitor vacuum performance on a regular basis. A vacuum with a pressure gauge allows for frequent and easy monitoring of air flow.
Remove all paints and coatings prior to welding. Paints and coatings may contain metals or other materials and generate hazardous fumes during welding.

As is the case with any construction equipment, users should follow manufacturer’s safety recommendations and comply with any applicable local, state or federal regulations.

OSHA, under 1926.353(a)(3), requires that local exhaust ventilation for welding consists of “freely movable hoods intended to be placed by the welder or burner as close as practicable to the work. This system shall be of sufficient capacity and so arranged as to remove fumes and smoke at the source and keep the concentration of them in the breathing zone within safe limits.” Applicable limits are found in Subpart D. OSHA, under 1926.353(a)(4), does not require that the exhaust air be filtered: “Contaminated air exhausted from a working space shall be discharged into the open air or otherwise clear of the source of intake air.”

OSHA’s new hexavalent chromium standard requires under 1926.1126(e)(1) that “the employer shall use engineering and work practice controls to reduce and maintain employee exposure to chromium (VI) to or below the PEL unless the employer can demonstrate that such controls are not feasible.” This means that welding or cutting where hexavalent chromium is present should include local exhaust ventilation.

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Availability

The Lincoln Electric Company
To obtain information, visit Miniflex Portable Fume Extractor or contact 1-888-935-3876

Air Distribution Technologies, Inc.
To obtain information, visit Air Boss One Trion Man Portable HEPA Air Cleaner or contact 1-919-775-2201 customerservice@trioniaq.com

Sentry Air Systems, Inc.
To obtain information, visit Portable Fume Extractors or contact 1-800-799-4609 sales@sentryair.com

Enviroflex International, Inc.
To obtain information, visit Portable Welding Smoke Extractors or contact 1-877-368-3539

Solution Summary: Portable Vacuum Fume Collectors with HEPA Filtration

Description:

Risks Addressed:

How Risks are Reduced:

Effects on Productivity:

Additional Considerations:

Contributors:

Hazards Addressed:

Availability

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