FOR PROTECTING MINERS AT SMALL SURFACE

M/NM MINES(Crushed Stone, Sand & Gravel, etc.)

Rocky Mountain DistrictDenver, CO

AIR QUALITYAIR QUALITY30 CFR § 56.5002

“EXPOSURE MONITORING”

•Dust, gas, mist and fume surveys shall be conducted as frequently as necessary to determine the adequacy of control measures.

• Airborne Contaminants

Airborne Contaminants ?• What are they at your mine?

– Mineral Dust ?• Silica/Quartz (Respirable)• Nuisance Particulate• ????Fibers

– Fumes?• Welding• Solvents

– Gases and Mists?• CO (shops, enclosed workplaces, cabs,

booths)• Cleaning (atomizing)

– Others………..?

What Are Dusts?

• Solid particles suspended in air

• Generated by blasting, drilling, crushing, grinding, etc.

The Body Defends Against Dust By:

• Trapping larger particles in the nasal passages, throat, trachea, larynx

• Trapping particles in mucous and carrying them up the airways where they are coughed out or swallowed (mucociliary escalator)

Silica dust may be a hazard, if

• it is in the respirable range: small enough to get into the air sacs (alveoli) ----basically less than 10 microns in size

• it is present in high enough concentrations

bronchiole

alveoli

How Does Silica Affect The Body?

• Silica particles build up in the lungs leading to a type of dust disease (pneumoconiosis) called silicosis

• Makes affected workers more susceptible to TB

• Causes cancer

Silicosis : Severity of Disease

Dust Concentration

Percent of free silica

Duration of exposure

Size of particles (respirable??)

Development of Silicosis is:

• More Likely With:

• Inadequate dust control measures

• Inadequate respiratory protection

• Lack of medical screening

• Lack of air monitoring

NUISANCE PARTICULATES(Total Dust)

• TLV: 10mg/M3

• IRRATANT– Respiratory system– Sinus membranes– Mucous tract– Skin– Eyes

Some Nuisance Particulate*

• Alundum• Calcium Carbonate• Cellulose (paper fiber)

• Portland Cement• Corundum• Emery• Glass, fibrous or

dust• Glycerin Mist• Vegetable oil mists

(some exceptions)

• Kaolin• *Sio2 less than 1%

• Limestone• Magnesite• Marble• Pentaerythritol• Plaster of Paris• Rouge• Silicon Carbide• Starch• Sucrose• Tin Oxide• Titanium Dioxide

Evaluate Worker Exposures By:

•Doing work area inspections

•Sampling, monitoring workers

•Observing work practices

Monitoring: Personal Exposures

REDUCE Dust Exposures:

• Assess potential for exposure• Use engineering controls, such as:Dust CollectorsEnvironmental cabs and boothsWater SpraysHEPA Filters and Vacuum (Don’t

cleanup with brooms/shovels)

M62.11062.110MMust establish: SYSTEM OF MONITORING

MPerformance based.

MSystem sufficient to determine compliance with rule.

MAssess miner’s noise exposure over full work shift.

Noise MonitoringMSpecific requirements for determining

miner’s noise dose.

MUse appropriate integration range: M80-130 for AL M90-140 for PEL and DHPL

andM 90 dBA criterion levelM 5 dB exchange rateM A-weighting & slow response

Cannot adjust for hearing protector worn.Cannot adjust for hearing protector worn.

Noise Monitoring

MNotify miner of exposure at or above AL, and above the PEL and DHPL.

MMust be in writing and given to miner within 15 days of determination.

MCopy must be kept as long as miner exposed at or above AL, plus 6 months.

MMiners and their representative have right to observe monitoring. (no pay required)

ADMINISTRATIVE CONTROLS

ROTATE WORKERS / WORK SCHEDULES

ESTABLISH REGULATED AREAS

PUT UP WARNING SIGNS & BARRICADES

ELIMINATE THE JOB

IMPROVE EDUCATION & TRAINING

CONTROL AT POINT OF WORKER

JOB ROTATION

ENCLOSURE

PERSONAL PROTECTIVE EQUIPMENT

TRAINING & EDUCATION

PERSONAL MONITORING

MAINTENANCE PROGRAM

MINERS:

OBSERVE RULES -� work practices, cleanup, hygiene

NOTIFY SUPERVISORS OF HAZARDOUS CONDITIONS AND PROBLEMS WITH CONTROL MEASURES

MAINTENANCE USE REQUIRED PPE