§ Mr. Hooleyasked the Secretary of State for Employment (1) what level of pentachlorophenol in industrial compounds or chemicals would constitute a hazard to the health of workers using them;
(2) what level of ingestion of pentachlorophenol compounds would cause serious damage to internal organs; and what biological tests have been made of it by the Health and Safety Executive, the Pesticides Advisory Committee or other public health bodies;
(3) what action has been taken by the Health and Safety Executive to examine the effects on workers of pentachlorophenol, a dioxin contained in wood preservatives.
§ Mr. Mayhew[pursuant to his reply, 29 April 1980, c. 324–6]: The extent to which pentachlorophenol in industrial compounds would constitute a hazard to the health of workers using them would depend upon not only the concentration but also the duration and type of exposure, for example, splashes on the skin, inhalation of droplets or ingestion. The pesticides safety precautions scheme recommendations for safe use, which should appear on the product labels, take these matters into account.
The Health and Safety Executive's guidance note EH 15/78 gives the threshold limit value for exposure to airborne concentrations of pentachlorophenol as being 0.5 mg/m3, but makes special reference to the particular dangers of skin contact associated with this chemical. Threshold limit values refer to airborne 111W concentrations of substances to which it is believed that nearly all workers may be repeatedly exposed during a seven to eight-hour work day and a 40-hour working week without adverse effect. The guidance note is revised annually and EH 15/79 to be published shortly will give the same threshold limit value.
Animal studies indicate that ingestion of repeated doses of 280 mg of pentachlorophenol per day over an extended period would be likely to cause damage to internal organs in humans and that ingestion of a single dose of 7 g—approximately ¼ oz—could prove fatal. However, because of their noxious taste and odour, the likelihood of accidental ingestion of formulations containing pentachlorophenol is considered remote.
Pentachlorophenol itself is not a dioxin but the commercial product contains certain impurities amongst which are a number of chlorinated dioxins. The specific dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has not, to the knowledge of the Health and Safety Executive, been detected in any samples of pentachlorophenol sold in the United Kingdom for use in wood preservatives.
No biological tests on pentachlorophenol have been carried out by the Health and Safety Executive, nor by the Advisory Committee on Pesticides—it is not a function of the committee to do so—nor, so far as the Health and Safety Executive is aware, by other public health bodies in the United Kingdom. The Health and Safety Executive is aware of the considerable number of animal studies into acute and chronic effects from both pentachlorophenol and its impurities which have been reported in the scientific literature.
A study reported in the journal of the Institute of Wood Science in 1966 of workers specifically involved in the wood preserving industry did not show any adverse effects which were considered to be occupationally related; the workers studied were involved in the use of a number of pesticides including formulations containing pentachlorophenol. At its last review of pentachlorophenol in December 1979 the Advisory Committee on Pesticides expressed the view that a further study should be undertaken of persons exposed at work to pentachlorophenol. Such a study is currently being 112W planned by the Health and Safety Executive.
§ Mr. Hooleyasked the Secretary of State for Employment (1) which EEC countries have placed limits on the use of pentachlorophenol in wood preservative or other compounds in common industries or domestic use;
(2) which public bodies are responsible for monitoring the level of dioxin compounds and toxicity in wood preservative;
(3) how many wood preservatives on sale to the public contain the dioxin pentachlorophenol; and what health warnings are given on the packaging;
(4) what limits are placed on the dioxin content of wood preservatives used in the timber and furniture trades, in particular the level of pentachlorophenol.
§ Mr. Mayhew[pursuant to his reply, 29 April 1980, c. 324–6]: Twenty-one wood preservative products containing pentachlorophenol have been notified to the Health and Safety Executive and cleared through the pesticides safety precautions scheme for sale specifically to the public, subject to the incorporation on product labels of official recommendations for safe use; between 60 and 70 other pentachlorophenol wood preservatives have been cleared for use solely by professional operators or for use in the industrial treatment of timber.
Health warnings are being modified to bring product labels into line with the requirements of the EEC directive 78/631/ EEC on the labelling of pesticides, and therefore existing labels will vary in detail in the meantime. They should, however, include recommended hazard warnings and precautionary advice broadly as follows:
Harmful by skin absorption and if swallowed Irritating to skin and eyesWear overalls and synthetic rubber/PVC gloves Take off immediately all heavily contaminated clothingWash splashes from skin or eyes immediatelyAvoid working in spray mist or wear respiratory equipment and eye protectionWash hands and exposed skin before meals and after work When using do not eat, drink or smoke If you feel unwell seek medical advice.The percentage of pentachlorophenol in ready-for-use wood preservative formulations is limited, under the pesticides safety 113W precautions scheme to a maximum of 6 per cent.
Pentachlorophenol is not itself a dioxin but the commercial product contains certain impurities among which are a number of chlorinated dioxins. The specific dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has not, to the knowledge of the Health and Safety Executive, been detected in samples from pentachlorophenol sold in the United Kingdom for use in wood preservatives.
No specific limit is placed on the level of dioxins in wood preservatives, but the levels of dioxins, other impurities and their toxic effects are taken into account when the data are assessed under the pesticides safety precautions scheme. The Health and Safety Executive, with advice from the Advisory Committee on Pesticides, is responsible for the assessment of the toxicity of wood preservatives notified under the pesticides safety precautions scheme. No monitoring is carried out by the Health and Safety Executive on the levels of dioxins in wood preserving products, but suppliers provide information on the nature and levels of significant impurities.
The Health and Safety Executive is not aware of any official limitations placed by any EEC country on the use of pentachlorophenol in wood preservatives or other compounds in common industrial or domestic use.