Multiple hazards

Pesticide exposure victim, Margaret Reichlin, claims recent treatment of her property with a white spirit-based water sealant has released toxic chemicals from previous work carried out. David Buffin reports.

In May 1988 contractors treated the cellar of Miss Reichlin's house in Upper Enham, Hamphire, England, for rot and woodworm.  
    They did a very poor job, and as a result of exposure to a cocktail of toxic chemicals, Miss Reichlin suffered considerable immediate adverse reactions, and developed longer term ill effects.  She became highly sensitised to pentachlorophenol (PCP), lindane and tributyltin oxide (TBTO)  (see PN25 p6).  
    According to an independent consultant, Miss Reichlin reacted strongly to the chemical vapours, showing soreness and irritation of the eyes, nose and throat, headache and abnormal breathing. This reaction is characteristic of acute exposure to the chemicals to which she was exposed.
    The Health and Safety Executive (HSE) Pesticide Incident Appraisal Panel later (in 1992) confirmed the incident as a Pesticide Ill-Health Incident.
    In addition to the ill-health, Miss Reichlin spent £26,000 (US$40,000) on renovations in an attempt to make her home habitable again. She has received no compensation for her chemical induced nightmare.

PCP released by solvent  
More recently Miss Reichlin's tale of woe took an unexpected twist. On 30 July 1996, she had waterproofing treatment carried out to an external wall of her house (see photo). The material applied, a white-spirit-based water sealant, overlapped onto some timber previously treated with preservative.
    Miss Reichlin reacted strongly to the chemical vapours. According to Mr Pearson, an independent expert: "An Environmental Health Officer confirmed both a 'chemical smell', and that fabrics in the house had been contaminated." The HSE did no chemical analysis at the time of the incident.
    The white spirit-based water sealant contains a solution of flexible resin in a volatile hydrocarbon solvent. Mr Pearson says: "If such a product leached through to, or was applied to, wood previously treated with preservative, it is reasonable to suggest that there may be a rapid movement of re-dissolved preservative material back to the surface, from which it will again evaporate, causing a significant increase in atmospheric concentration."(1)
    Miss Reichlin is now concerned that liberation of previous timber treatment in her case could include PCP. "This disaster has cost me £3,000 in remedial work, and I have been affected by exposure to these chemicals for more than a year," she complained.

A historical legacy  
The HSE position is unclear as to whether there is a 'release' of timber treatment chemicals following the application of white spirit based products. In a letter to Miss Reichlin, J Pickering of the HSE said: "There appears to be no information or data available to indicate that this type of product could release timber treatment chemicals."(2)
    In another assessment, a paper commissioned by the HSE Laboratory confirmed the uncertainty. It says: "There is very little published data which relates directly or indirectly to the question of PCP mobility in wood following treatment with solvents. Therefore we are not able to form a firm and solid opinion as to the behaviour of PCP in wood following treatment with solvent."(3)
    This opinion differs from that of academics such as David Watt of the Department of Building Surveying at De Monfort University and the British Wood Preserving and Damp-proofing Association (BWPDA). Les Hill, Technical Officer at BWPDA said in a letter to Miss Reichlin: "In general terms, wood preservatives available in the mid 1980s were of organic solvent type, dissolved in white spirit or a similar solvent, which penetrate quite deeply into timbers. When the carrier solvent evaporates the active ingredients are left on the surface and also at depth in the treated timbers. Because the active ingredients are not soluble in water, they cannot subsequently be leached out by rain etc. However, they can be leached out of treated timber by organic solvents in which they will dissolve. Indeed analysis of treated timber for the presence of these wood preservatives in the laboratory depends on this fact. It is accepted within the industry that some re-distribution of active ingredients can occur. It therefore follows that a surface application of a suitable solvent could cause some re-distribution of active ingredients from deep in the timber back to the surface."(4)
    The BWPDA opinion therefore seems to support the theory that PCP applied years before could be liberated by a subsequent application of a white spirit-based water sealant. The problem may also have been caused by solvent vapour released during sealant treatment, according to BWPDA.  
    There is growing concern among some experts about past chemical treatments and their impact on the household environment.
    This has been highlighted by  David Watt: "It is clear that the problems of chemical treatment residues in buildings have not been widely considered or reported. The few papers published, concentrate on the continuing role of remedial treatment companies in providing a service to building owners and their professional advisors, rather than on the problems posed by previous treatments."(5)

Unsatisfactory tests  
In August 1997, the HSE took some samples of Miss Reichlin's breath and urine, to establish PCP levels. The tests were negative. This was no surprise to Miss Reichlin who felt the HSE should have tested structures and objects in her house, rather than testing for residues in her body.

Labelling requirement?  
Miss Reichlin is concerned that the labels of white spirit-based water sealants do not warn against the likelihood of old chemicals leaching out after subsequent application. She does not want others to develop similar problems.  
    However at present, the current label does not contain a hazard symbol, has no indication that the product contains white spirit, and is perfectly legal under the Chemicals, Hazard Information and Packing for Supply (CHIPS) in Regulations.

Conclusion  
There are two main points that arise from this case. Firstly, the impact of historical timber treatment in buildings needs further investigation. Secondly, the label on white spirit based water sealants should warn about the possible release of previously applied timber treatment.
    PCP is a persistent organic pollutant, and its possible liberation into the environment is of general concern as there are probably a number of cases where such chemicals have been applied in similar fashion.

1. Statement by CR Pearson, MA CEng MIChem E, 18 November 1996.  
2. Letter to Margaret Reichlin from JR Pickering HSE Inspector, 26 September 1996.  
3. Curran, AD, and Chambers, H, Pentachlorophenol: Leaching and Migration Properties, Health & Safety Laboratory, Sheffield, UK, 1997.  
4. Letter to Margaret Reichlin from L Hill, BWPDA, 24 January 1997.  
5. Watt, D., Chemical treatment residues in buildings, De Monfort University, presented at the Annual Royal Institute of Chartered Surveyors, University of Portsmouth, 11 September 1997.

[This article first appeared in Pesticides News No. 38, December 1997, page 8]