RESPIRABLE DUST SAMPLERS Presented by .

RESPIRABLE DUST SAMPLERS

Presented by

www.skcinc.com

THE HAZARD POTENTIAL OF AIRBORNE PARTICULATES

Determined by: Chemical composition Concentration in air Size characteristics

SIZE CHARACTERISTICS OF AIRBORNE PARTICULATES

Determine the

deposition site in

the respiratory

system and the

ultimate health

effects for exposed

individuals.

SIZE-SELECTIVE EXPOSURE LIMITS AND GUIDELINES

To more appropriately assess the possible

health effects of airborne particulate

matter, occupational exposure limits and

guidelines including the Threshold Limit

Values (TLVs®) have been issued for

different sizes of particles.

RESPIRABLE DUSTDEFINED

The TLV booklet defines respirable particulate matter as those materials that are hazardous when deposited in the gas-exchange region of the lung.

Samplers designed to collect only the respirable fraction of airborne particulate matter should be used when the target compound has an established limit issued as respirable dust.

WHY USE A RESPIRABLE DUST SAMPLER?

Size-selective respirable dust samplers enable separation and collection of this specific size fraction from all the suspended particulates in air.

Collecting larger, non-respirable particulates would inflate results of the sample, overestimating exposure.

SPECIFICATIONS FOR RESPIRABLE DUST SAMPLERS

Performance specifications for respirable dust samplers have been issued by various scientific organizations and standard setting bodies throughout the world.

The performance specifications are issued as collection efficiency curves that specify the efficiency of a dust sampler for particles of designated sizes.

50% CUT-POINT:A PERFORMANCE SPECIFICATION

The 50% cut-point is often used to describe the performance of respirable dust samplers.

It is the particle size that the sampler can collect with 50% efficiency.

Particles smaller than the 50% cut-point of the cyclone are collected with an efficiency greater than 50%.

Larger particles are collected with an efficiency less than 50%.

CURRENT SPECIFICATIONS

Most organizations involved in occupational hygiene now recommend the use of respirable samplers designed to meet the specifications in ISO Standard 7708:1995.

This ISO standard has already been adopted by ACGIH, CEN, and NIOSH. U.S. OSHA has proposed adoption of this ISO Standard in their 2013 notice of proposed rulemaking for respirable crystalline silica.

CURRENT SPECIFICATIONS

The ISO standard for respirable dust samplers specifies the collection efficiency curve for respirable dust samplers.

This curve includes a 50% cut-point of 4 um. This is a more conservative curve than the

existing U.S. OSHA/MSHA regulations that specify a collection efficiency curve with a 50% cut-point of 3.5 um.

TRADITIONAL RESPIRABLE DUST SAMPLERS: CYCLONES

Named for the rotation of air within the chamber

Function on the same principle as a centrifuge

Use rapid circulation of air to separate particles according to their aerodynamic diameter

CYCLONE OPERATION Air enters through a slit on

the side of the sampler which creates cyclonic action.

Large particles fall into the cap (grit pot) and are discarded.

Small particles are thrown up onto the filter for analysis.

Cap must be in place.

CYCLONES AVAILABLE FROM SKC

Aluminum Cyclone Meets ISO/CEN criteria at

flows of 2. 5 L/min Eliminates adverse

electrostatic effects Specified in NIOSH

Methods for respirable dust and respirable crystalline silica

SKC 225-01-01/02


GS-3 Cyclone Conductive plastic Suitable for underground

mine use Eliminates adverse

electrostatic effects Multi-inlet design

overcomes orientation bias Listed in OSHA proposed

rulemaking on silica Meets ISO/CEN criteria at

flows of 2.75 L/min


GS-1 Cyclone Constructed of same

conductive plastic material as GS-3

Single inlet design serves as a Dorr-Oliver equivalent for existing U.S. OSHA/MSHA requirements

• Meets ISO/CEN criteria at flows of 2.0 L/min

SKC 225-100/103

CYCLONES AVAILABLE FROM SKC IN UK

Conductive Plastic

Cyclone Meets ISO/CEN criteria at

flows of 2.2 L/min Features a snap together

cassette Static dissipating

SKC 225-69/-37

IMPORTANT NOTE ON FLOWRATE

All cyclones are not created equal!

Each cyclone has different operating specifications and performance criteria.

Be sure you know the flow rate specified to achieve the desired cut-point before using any cyclone.

TIPS FOR SAMPLING WITH SKC AL OR GS CYCLONES

Load filter into a 3-piece filter cassette. Place cyclone into middle ring. Calibrate the pump with sampler in line. Take sample at specified flow rate. Remove filter & cyclone from sample train. Recap and send filter to lab.

Clean cyclone before reuse.

TIPS FOR CALIBRATION

SKC Aluminum CycloneHas a handy calibration adapter that fits over the cyclone and allows standard tubing to be attached for connection to the pump calibrator.

The chamber fits both the 25-mm and the 37-mm aluminum cyclones.

SKC 225-01/2

SKC

225-01-03

TIPS FOR CALIBRATION Calibration Jar SKC 225-111/112

Very large jars are not recommended when calibrating with the piston-style primary calibrators like the Defender. The dead volume in the jar can affect the rise/fall of the piston causing the readings to be erroneously low!

TIPS FOR CALIBRATION Calibration Jar SKC 225-111/112

Use the smallest jar possible to contain the cyclone/filter assembly. SKC offers a calibration jar suitable for the SKC GS or other samplers of similar size.

TIPS FOR CALIBRATION Another option is the so-

called “jarless” calibration method when using piston-style primary calibrators.

Attach the pump only to the suction port and the cyclone/filter assembly to the other port on the calibrator. This will create the same pressure drop as the sampling train assembled in the field.

POST-SAMPLE CLEANING After sampling, clean all parts of the cyclone, with mild

soapy water Don’t forget to clean the grit pot. Dry the cyclone. (Air-dry or blow-dry) Wipe with a dust-free tissue or wipe with an isopropyl

alcohol moistened pad. Caution: Do not use strong solvents to clean plastic

cyclones

A NEW RESPIRABLE DUST SAMPLER FROM SKC

SKC has developed a new impactor based sampler for respirable dust called the Parallel Particle Impactor or PPI.

The PPI was designed to improve performance characteristics evidenced with older traditional cyclones.

PPI SAMPLERS FROM SKC

Specifically designed to precisely match the new criteria for respirable samplers specified in the ISO 7708 standard that is followed by most occupational hygiene organizations around the globe.

PPI SAMPLER PERFORMANCECOMPARED TO CRITERIA

0

25

50

75

100

1 10

Aerodynamic Particle Diameter, da, mm

Pene

trati

on, P

, %

Respirable PPI, 2.0 L/min



ISO/CEN Respirable Criteria

5

SKC RESPIRABLE PPI:FUNCTIONALITY

The disposable models of the PPI look and function very much like a traditional 37-mm cassette.

But the inlet comes pre-loaded with size-selective impactor plates that scrub out non-respirable dust.

PPI samplers are smaller than traditional cyclones and can fit under a welder’s helmet or other PPE.

SKC RESPIRABLE PPI:FLOWRATES

Single-use, disposable PPI models are available for use at either 2, 4, or 8 L/min.

This provides flexibility in pump options, sample duration, and concentration.

4 L/min: 225-387

8 L/min: 225-384

2 L/min: 225-385

IMPORTANT NOTES ON THE PPI

Disposable PPI samplers are available from SKC pre-loaded with designated filters or your lab can load the filters into the PPI.

Reusable PPI samplers made of aluminum are also available for those that want to assemble, clean, and reuse.

A calibration adapter is available for the PPI as SKC 225-389.

THANK YOU FOR YOUR INTEREST

Please visit the SKC website for more training options and details on SKC samplers.

Email [email protected] with questions or contact your local SKC representative.

www.skcinc.com

RESPIRABLE DUST SAMPLERS Presented by .

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