THE SCHUNDLER COMPANY
FOR POSSIBLE ASBESTIFORM FIBRE
BASED ON VERMICULITE FROM PALABORA, SOUTH AFRICA
by
IOM CONSULTING
Sampling and analysis of crude vermiculite stocks
1. INTRODUCTION
Palabora Europe Limited is the European distributors of vermiculite produced by the Palabora Mining Company from open cast mines at Phalaborwa, Transvaal, South Africa.
In order to address concern on Health and Safety issues in the world-wide market for vermiculite, Palabora Europe have previously commissioned the IOM to undertake a detailed analysis of vermiculite from the main PP & V ore body at Phalaborwa and one grade from the adjacent VODT deposit. This original study produced favourable results and was followed up by a less detailed routine screening exercise. This investigation was a continuation of the routine screening exercise.
IOM Consulting was therefore invited to carry out a further independent sampling and analysis exercise on behalf of Palabora Europe Limited. The main aims were to collect representative samples from each grade of vermiculite as available in the European market, split them and analyse them at the IOM Consulting's Edinburgh headquarters for asbestiform mineral content.
2. SAMPLING
Mr Steve Clark of IOM Consulting and Mr Mike Darling of Palabora Europe Limited visited the Palabora Europe Ltd vermiculite bulk store at North Killingholme Humberside, on 13th November 2002. At the North Killingholme site, six different grades of vermiculite (micron PP & V, superfine PP & V, fine PP & V, medium PP & V, large PP & V and superfine VODT) were stored inside large silos of approximately 27 metres diameter and 9 metres high. The approximate stocks at the time of sampling are summarised in Table 1.
Samples were collected from each grade as representatively as possible, by clearing away loose dust from the top of the material and digging into the stock as far as possible, avoiding any material falling in and re-mixing. A number of sub samples per site were extracted and mixed from each stockpile. Each sample was split on site with one sample being retained by Palabora Europe and the rest by IOM Consulting.
For the respirable and total inhalable dust and quartz simulation, additional vermiculite was collected from the PP & V micron grade.
Sample Analysis Protocol
The main objective was to identify any hazardous asbestos fibres present in the vermiculite. This was achieved as follows:
A portion of each sample was examined for the presence of fibrous asbestiform minerals at X8 - X40 magnification using stereo-binocular microscopy. Any fibres detected, were mounted in appropriate refractive liquid and identified at 125X magnification using Polarised Light Microscopy (PLM) and dispersion staining microscopy. The method used was based upon MDHS 77 (HSE, 1994a).
This part of this analysis was carried out under IOM's external quality accreditation, awarded by the United Kingdom Accreditation Service (IIKAS).
4. RESULTS :
Polarised Light Microscopy Examinations
No amphibole or chrysotile asbestos fibres were detected in any of the samples of crude vermiculite collected. Therefore, quantitative analysis of the vermiculite materials was not undertaken.
A summary of results for the PLM analysis is given in Table 2. Certificates of Analysis for the PLM analyses are also attached (Appendix 1).
5. COMMENTS
No amphibole or chrysotile asbestos fibres were detected in the bulk samples of any of the vermiculite samples tested by Polarised Light Microscopy. The detection limit usually quoted for this method is around lppm by mass (HSE, 1994a).
Therefore, all of the vermiculite materials tested comply with the proposed 0.1% European packaging and labelling of carcinogen requirements (HSE, 1994b) and the 0.1% trigger value required for labelling of hazardous materials in the US.
The levels are also lower than the 0.00 1% for asbestos in loose aggregates proposed by Addison et al (1988) based on work at the IOM using asbestos and soil mixtures. Therefore, it is concluded that these materials or products containing them should not present a significant asbestos-related health hazard when used in controlled occupational environment.
SAMPLED BY: ANALYSED BY: AUTHORIZED BY:
Table 1.
CONTRACT NO: 946E PROJECT NO: 161
Sampling and analysis of crude vermiculite stocks
Table 1. Details of Crude Vermiculite Stocks at North Killiugholme
Table 2.
CONTRACT NO: 946E PROJECT NO: 161
Sampling and analysis of crude vermiculite stocks
Table 2. Results from the Polarised Light Microscopy evaluation of vermiculite samples
The Schundler Company Back to Technical Information on Vermiculite, or
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Edinburgh, Scotland
November 2002
at the Palabora Europe Ltd store at North Killingholme
CONTRACT NO: 161/946E PROJECT NO: 161
3. METHODS
S Clark
Senior Scientific Technician
A Cameron
LST Davies
Scientific Technician
LST Davies
Senior Mineralogist
at the Palabora Europe store at North Killingholme
on 13 th November 2002
Vermiculite Grade Approx. Stock on
13.11.02 (tonnes)Micron (PP & V) 1717 Superfine (PP & V) 1803 Fine (PP & V) 1422 Medium (PP & V) 200 Large (PP & V) 711 Superfine(VODT) 624
at the Palabora Europe store at North Killingholme
from the Palabora Europe Store, North Killiugholme
IOM Sample No. Description Asbestos Type Detected
E21348 Superfme (PP & V) None Detected
E21344 Fine (PP & V) None Detected
E21347 Campaign Superfine (VOD T) None Detected
E21346 Medium (PP & V) None Detected
E21345 Micron (PP & V) None Detected
E21349 Large (PP & V) None Detected
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