Innovation Partners for Aerobiology & Biomedical Research

For this blog entry, we discuss the occurrence of "Popcorn workers lung" attributed to diacetyl inhalation, following the recent legal proceedings of a Bronchiolitis obliterans (BO) sufferer who contracted the respiratory disease following exposure to diacetyl from Popcorn. BO is an obstructive respiratory disease, whereby the bronchioles are obstructed by tissue damage and aberrant epithelial repair. The result is a narrowing of the bronchioles, restricting normal respiratory function. This should be of concern to managers and safety officals of manufacturing plants producing diacetyl and whos employees or consumer base may be at risk from exposure. 

This post has been written by Peter Desmond, a scientific contributor at airmid healthgroup. Peter is a graduate of Trinity College Dublin with a B.A (mod) in Microbiology.

Recent studies conducted on vacuum cleaner emissions, have vacuum cleaners as a potential source of indoor exposure to airborne allergens, bacteria and other pathogens.

In this blog post I review the issues around this occurrence and the steps manufacturers of vacuum cleaners can take to ensure their products meet certification standards, in particular the asthma & allergy friendly certification standard.  As an accredited immunoassay testing facility airmid healthgroup is a designated laboratory for the program.

This blog is written by Peter Desmond, scientific contributor at airmid health group. Peter is a gradate of Trinity College Dublin with a B.A (mod.) in Microbiology

The testing of vacuum cleaners and similar domestic electrical appliances such as air cleaners involves the use of "test-dust"; inert particles consisting of silicon dioxide, aluminium, iron and sodium oxides. It is used to mimic typical household dust, which is composed of a mixture of fibres and particles of varying sizes and compositions. Sources of which include skin, mites, soil, heating emissions and pollen grains. In this blog post, we talk to Dr. Angela Southey, a lead researcher at airmid healthgroup, about a recent study she conducted and presented at the prestigious 13th International Conference on Indoor Air Quality and Climate in Austin, Texas comparing the characteristics of ISO fine test dust to real house dust.

Introduction to the study

Domestic products, such as vacuum cleaners, are often tested using inert particle mixtures called 'test dust'. Depending on the standard's testing requirements, the test dust consists of a defined mixture of silicon dioxide, aluminium, iron and sodium oxides and other components such as talcum powder, wood flour and potassium chloride (ASTM. 2007, CEI IEC. 2004, ASTM. 2004). The test dusts are graded according to their particle size range. ISO 12103-1 A2 Fine Test Dust (or ISO Fine Dust) is a test dust with a particle size range from 1-80m. ISO Fine Dust is used in ASTM standard F2608-07 (ASTM. 2007) for determining the change in room air particulate counts as a result of test dust removal from floor coverings with the vacuum cleaner under test. Household dust is composed of a heterogeneous mixture of fibres and irregularly shaped particles of varying particle sizes and composition. Particle sources include skin, hair, mites, plant pollen, fibres, soil, road dust, cooking emissions, heating emissions and cigarette smoke (Edwards et al. 1998; Molhave et al. 2000). Comparison of the particle size distribution of the ISO Fine Dust with that of household dust by laser diffraction, demonstrated that ISO Fine Dust bears little resemblance to the 'real' dust that a vacuum cleaner would encounter in the home (nor does it purport to).

The aim of this study was to determine if a test dust, more representative of household dust, should be produced and standardized for domestic appliance testing.

ASHRAE 52.2 is a method of testing general ventilation air cleaning devices to determine their removal efficiency as a function of particle size. It is a method that determines the ability of an air filter to remove particles on the basis of specfic particle sizes ranging between 0.3 to 10 microns. A central feature of ASHRAE 52.2 is the incorporation of the Minimum Efficient Reporting Value (MERV) for each filter tested. Angela Southey is the head of the environmental test chamber at airmid healthgroup. In this interview, we ask Angela about Airmid’s new ASHRAE 52.2 test duct, its functional association with the Environmental Test Chamber and the importance this facility has for HVAC testing, MERV testing and its potential for contract research.

This article has been written in Q and A format following an interview with Angela Southey PhD at the test facility at airmid healthgroup and is a hugely informative interview on the subject.