Edinburgh, Scotland
August 2003

Analytical Science

Sampling and analysis of crude vermiculite stocks
at the Palabora Europe Ltd store at North Killingholme

PROJECT NO: 610-00335


    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 LOM Consulting 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.


    Mr. Steve Klek of IOM Consulting and Mr. Mike Darling of Palabora Europe Limited visited the Palabora Europe Ltd vermiculite bulk store at North Killingholme Humberside, on 5th August 2003. At the North Killngholme site, five different grades of vermiculite (micron PP & V. superfine PP & V, fine PP & V, medium PP & V and large PP & V) were stored inside large silos of approximately 27 metres diameter and 9 metres high. The approximate stocks at the time of sampling are summarized 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.

    Sample Analysis Protocol

    The main objective was to identify any hazardous asbestos fibres present in the vermiculite. This was achieved as follows:

    • Initial examination by stereo-binocular microscopy and polarised light microscopy using methods described in HSE document MDHS 77 (HSE, 1994a).

    • Quantitative assessment of amphibole asbestos by electron microscopy and X-ray diffractometry of any sample for which asbestos fibres were detected in (i) above.


    Initial Examination

    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 (UKAS).


    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).


    No amphibole or chrysotile asbestos fibres were detected in the hulk samples of any of the vermiculite samples tested by Polarised Light Microscopy. The detection limit usually quoted for this method is around l ppm by mass (HSE, 1 994a).

    Iherefore, 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 0.001% for asbestos in loose aggregates proposed by Addison et aI (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.

S Klek
Senior Occupational Hygienist

T Sodergren
Scientific Technician

LST Davies
Senior Mineralogist

Table 1.

PROJECT NO: 610-00335

Sampling and analysis of crude vermiculite stocks
at the Palabora Europe store at North Killingholme

Table 1. Details of Crude Vermiculite Stocks at North Killiugholme
on 5TH August 2003

Vermiculite GradeApprox. Stock on
05.08.03 (tonnes)
Micron (PP & V) 1202
Superfine (PP & V)2217
Fine (PP & V) 1314
Medium (PP & V) 541
Large (PP & V) 179
Superfine(VODT)No Stock

Table 2.

PROJECT NO: 610-00335

Sampling and analysis of crude vermiculite stocks
at the Palabora Europe store at North Killingholme

Table 2. Results from the Polarised Light Microscopy evaluation of vermiculite samples
from the Palabora Europe Store, North Killiugholme

IOM Sample No. DescriptionAsbestos Type Detected
E28967 Superfme (PP & V) None Detected
E28966 Fine (PP & V) None Detected
E28965 Micron (PP & V) None Detected
E28964 Medium (PP & V) None Detected
E28963 Large (PP & V) None Detected

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