Particulate, Gas & Vapor(Sampling Equipment)

Cindy Hammons

PARTICULATE

Definitions

Aerosols – the dispersion of solid or liquid particles in the gaseous medium

Dust – dispersion of solid particles in the gaseous medium

Fumes – solid particles in a gaseous medium formed by condensation of solid materials (vapor)

Smoke – usually but not necessarily consist of solid particles

Shape, Size and Distribution

Various shape, size and density of particulate

AED is the diameter of a unit density sphere having the same settling velocity as the particle concern

Polydisperse dust cloud (geometric mean and geometric standard deviation)

Aerodynamic Behavior In Airstream Impaction – proportional to the momentum

i.e. mass and velocity Sedimentation – proportional to its diameter Diffusion – for particles < 0.1um

Size Selective and Selected Area of Deposition Nasopharyngeal deposition (upper

respiratory tract) – 7 to 20um Tracheobronchial (conducting airways) – 5

to 7um Alveolar region (gas exchange area) – 0.5 –

5um

Inhaled Dust Fractions (Sampling Instrument) Respirable dust – the dust fraction that will

penetrate to the unciliated portion of the lungs

Purpose of Sampling

Compliance with the requirement of the law Health risk assessment Epidemiological study Assessment of control measures

Type of Sampling

Area sampling Personal sampling

Type of Sample & Equipment

Total dust Inspirable dust – 7 hole sampler, IOM

sampler, close face sampler Respirable dust – BMRC horizontal

elutriator, AEC cyclone Thoracic dust – vertical elutriator Fibers – open face sampler with cowl

Sampling Equipment

Real time – piezobalance, dust counter etc Non real time – filtration, impaction

(cascade impactor)

GAS & VAPOR

Definitions

Gas – a state of matter in which a substance completely fills the region in which it is contained; has very low density and viscosity; can expand and contract greatly in response to changes in temperature and pressure; and easily diffuses into other gases e.g., CO, CO2, HCN, NH4, SO2, H2S, N2O, O3, Formaldehyde, phosgene, arsine, vinyl chloride etc

Vapour – the gaseous state or form of a substance which is normally in the liquid or solid state at room temperature and pressure. The liquid or solid may be reduced to the vapor by the action of heat. A vapor can be liquefied by a suitable increase in pressure e.g., toluene, xylene, alcohol, C2S, benzene, carbon tetrachloride etc

Physiological Effects

Carcinogens – vinyl chloride, benzene, benzidine, B-napthylamine, formaldehyde

Systemic poisons – C2S, parathion, hexane, chlorinated hydrocarbon

Asphyxiation – CO, CH4, HS, Na Nitrite Irritation – acid, alkali, O3, N2O, phosgene Anesthetic/narcosis – alcohol, ketones Sensitizer – TDI, formaldehyde

Physicochemical Properties

Solubility Melting and boiling points Vapor pressure Vapor density or relative density Flash point

CSDS

Physicochemical properties

Purpose of Sampling

Compliance with the requirement of the law Health risk assessment Epidemiological study Assessment of control measures

Type of Sampling

Area sampling Personal sampling

Sampling Equipment

Real time Non real time

Sampling Equipment (examples)

Charcoal tubes with pump Passive sampler (diffusion membrane) Bubbler (midget impinger) MIRAN Portable gas chromatography Detector tubes

Thank You