Asbestos TEM Laboratory
Find out more about our Transmission Electron Microscopy (TEM) service in Australia
Transmission Electron Microscopy (TEM) analysis
ITGA Group is a TEM laboratory specialised in asbestos analysis, identification and counting since 1996.
Transmission Electron Microscopy allows the detection, classification and identification of mineral fibres in bulk and air samples. With a minimum object size detection of just 1nm , TEM can see the smallest fibrils of carcinogenic asbestos (20nm) where traditional methods (PLM and PCM) are limited to 200nm.
Our asbestos services:
Detects, classifies and identifies commercial and non-commercial asbestos in bulk samples
Determines the real concentration of asbestos for air monitoring and clearance certificates
Natural Occurring Asbestos (NOA) analysis
Ghost wipes / Swabs analysis to determine the concentration of asbestos in surface sampling
Our environmental services:
SMF/RCF analysis
Fire residue analysis (soot and carbon black)
Erionite analysis
An expertise that ITGA brought in Australia in 2020 with the creation of its first international joint-venture: COHLABS-TEM. The very first NATA accredited facility in Oceania for asbestos testing using Transmission Electron Microscopy.
The golden standard for asbestos analysis:
Transmission Electron Microscopy (TEM)
What is TEM?
Transmission Electron Microscopy is a powerful tool for detecting, classifying, and identifying all types of asbestos and minerals thanks to :
- a very high magnification of more than x10.000
- a high-resolution of 0.1nm
- a minimum object size detection of 1nm
- the access to the atomic arrangement/crystal structure using the electron diffraction mode
- the access to the chemical composition using Energy Dispersion X-Ray Spectroscopy.
The concept of TEM is to produce electron at the top of the microscope within the electron gun by heating a tungsten filament which will send, through a vacuum column, electrons through the sample. The sample is disposed at the middle of the vacuum column by a specific sample holder. Comparing to SEM where electrons will reflect on the sample, here electrons will transmit the sample. All electrons will then hit the fluorescent screen enable the image recording system to produce the image you are looking for.
Advantages of TEM
AVOID FALSE NEGATIVE
TEM in able to detect very fine fibres that cannot be observed using PLM.
TEM can identify the non-commercial asbestos minerals such as tremolite, actinolite and anthophyllite which cannot be identified by PLM due to the wide range of optical properties these minerals exhibit.
Declaring there is no asbestos where there is – this is the worst-case while trying to managing asbestos in-situ. This can be avoided by utilising TEM.
Common asbestos containing materials not observable under PLM include; Vinyl tiles, sealants, mastics & epoxy resins.
AVOID FALSE POSITIVE
Working in environments that contain multiple organic fibres present? TEM can be used to confirm mineral fibres as being non-asbestos allowing the avoidance of unnecessary costs of specialist asbestos remediation where it is not necessary.
TEM distinguishes asbestos fibres from all other fibres to get the right result.
REAL EXPOSURE
Fibres released from ACMs are released in different sizes. Many of these asbestos fibres are thinner than 0.2 μm and therefore are not observable using Phase Contrast Microscopy (PCM).
By using TEM for your sample analysis you can avoid under-estimations in exposure:
TEM detects asbestos from .01μm.
In many cases, you’re exposed to Thin Asbestos fibres that you cannot detect with the PCM.
Generally speaking, TEM can accurately define the mystery mineral by morphology, chemistry, and crystal structure. As electron microscopy is the golden standard that complements other optical techniques:
TEM has a much higher resolution than other techniques. SEM and Optical Microscopes (PLM/PCM) does not detect Thin Asbestos Fibre (TAF) which are proven to be carcinogenic.
Especilly, chrysotile that has the ability to generate fibrils as thin as 20 nm in diameter, which is 10 times less than the separating power of an optical microscope and 5 times less than the minimum object size detection of a SEM.
TEM determines the crystal structure which is imperative in differentiating countless look alike mineral fibres that are not hazardous from asbestos minerals.
For example, some chemical compositions given by EDS of minerals such as talc and anthophyllite can be quite similar, thus asbestos can be differentiated and identified only with TEM thanks to the crystal structure/electron diffraction mode that shows a different pattern.
TEM has already proven-efficient standards in sampling, preparing and analysing asbestos, set by regulators such as NIOSH and AFNOR since early 90’s.
Why TEM for bulks?
- TEM is able to detect very fine fibres that cannot be observed using traditional Polarised Light Microscopy (PLM) Techniques.
- TEM can identify the non-commercial asbestos minerals such as tremolite, actinolite and anthophyllite which cannot be identified by PLM due to the wide range of optical properties these minerals exhibit.
Why TEM for air samples?
- TEM can avoid under-estimations in exposure as it can detect thin asbestos fibres of 0.02μm.
- TEM can complement existing Phase Contrast Microscopy counting techniques as it can distinguish asbestos fibres from all other fibres to get the right result. This eliminates both false positive and false negatives which can be costly to your clients.
