Ann. occup. Hyg., Vol. 45, No. 4, pp. 291–294, 2001Crown Copyright 2001

Published by Elsevier Science Ltd on behalf of British Occupational Hygiene SocietyAll rights reserved

Printed in Great Britain.0003-4878/01/$20.00

PII: S0003-4878(00)00090-9

Sharing Toxicological Information on IndustrialChemicalsPAUL OLDERSHAW* and STEVE FAIRHURSTHealth Sciences Division, Health and Safety Executive, Stanley Road, Bootle, Merseyside, UK

A clear and comprehensive appreciation of the toxicological hazards of a substance is anessential prerequisite to establishing appropriate, balanced and effective risk managementmeasures in the workplace. For many substances, there are currently numerous problemsand issues surrounding: the adequacy of the toxicological information base; its interpretation;the transfer of key messages to, and their understanding by, those who need to take action;and the roles and practices of the various standard-setting bodies operating in this area andthe interaction between them. This paper briefly touches on these issues, on a range of activi-ties and initiatives directed at improving the current situation, and on the implications forall those involved, particularly the world occupational hygiene community. Crown Copyright 2001 Published by Elsevier Science Ltd on behalf of British Occupational Hygiene Society.All rights reserved

Keywords: industrial chemicals; toxicity; information gathering; information transfer; standard-setting

INTRODUCTION

A clearly understood, well-communicated positionon the toxicological properties of a substance is anessential foundation stone for the development ofsound risk management positions and regulatorystandards. One then has a good basis for ident-ifying measures that should be employed to secureappropriate control of exposure in order to protectthe health of those exposed to the substance atwork.

Assembling a complete and robust toxicologicalprofile for a substance can be a complex task.There are multiple potential hazards to consider(e.g. acute systemic poisoning, eye irritation, skinsensitisation, genotoxicity and its potential conse-quences, reproductive toxicity) and the depen-dency on dose level, dose pattern and exposureroute for the expression of each of the hazards pos-sessed by the substance. A substantial amount ofraw data is required to enable all of these consider-ations to be addressed. Appreciable technical

Received 8 September 2000; in final form 15 November2000.*Author to whom correspondence should be addressed. Tel.:+44-151-951-3509; fax: +44-151-951-3197

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resource is necessary to process, critically analyseand interpret such information, distilling it into asuccinct, accurate and readily transferable toxico-logical picture.

The availability of this resource is restricted.Developing countries which might not yet have strongnational toxicological capability can be provided withsuch toxicological information by parts of the worldmore rich in this knowledge and expertise. There areseveral difficulties and barriers to overcome in pursu-ing this goal. Nevertheless progress is being made ona number of fronts. How things stand currently andthe way in which things seem to be progressing alsohas implications for the world’s occupational hygienecommunity. This paper considers briefly the issuesinvolved particularly in relation to occupationalexposure standards and their availability and usearound the world.

SOME OF THE PROBLEMS

Consideration of the current situation reveals a ser-ies of issues that create problems:

1. Shortage of Data. For many substances of occu-pational relevance, few toxicological studieshave been conducted and/or few real-life experi-

292 P. Oldershaw and S. Fairhurst

ences properly characterised and documented.Several analyses have concluded that there arefew or no toxicological data available on manyindustrial chemicals (National Academy ofSciences, 1984; USEPA, 1998, Allanou et al.,2000).

2. Conflicting positions on data interpretation. Forsome of the better studied substances, differentinterpretative positions on the conclusions thatshould be drawn are taken by different interestedparties in different parts of the world. In thisrespect there are as many issues of disagreementbetween different regulatory agencies as there arebetween ‘the regulatory authorities’ and other bod-ies, e.g. industry, academia and workers’ represen-tatives.

3. Poor transfer of toxicological information to thoseexposed. The primary methods of transfer of toxi-cological information along with any particularsubstance are via a label on the substance packag-ing and on an accompanying Material Safety DataSheet (MSDS). Although conceptually these enjoyuniversal recognition as means of communication,in practice different parts of the world employ dif-ferent (or no) labelling systems, based on differentprinciples, and the thoroughness, quality and clar-ity of the toxicological information carried onmany MSDSs is poor. There is also probably aneed for initiatives aimed at trying to improve theunderstanding of toxicological information bythose exposed.

4. Inefficiencies in the use of the available regulatoryand standard-setting toxicological resources.International co-operation and collaboration con-tinues to develop. Nevertheless, there remains atendency, for those (relatively few) bodies with theresources to distill, critically appraise and interpretsubstantial toxicological information, to duplicateactivity, often working on the same substances,and revisiting them, while leaving unexamined alarge number of other substances worthy of atten-tion.

5. Inadequate understanding of the science. It hasto be acknowledged that there remain manyissues in toxicology for which we lack a clearunderstanding. This may be at the level of anindividual substance, in terms of the way inwhich it expresses a particular experimental tox-icity finding and the relevance of this finding forhuman health. It may also be a more generalissue, for example the exposure pattern(s) thatare responsible for the induction of occupationalasthma, or the occurrence and, if so, means oflocating a practical threshold for the productionof cancer for genotoxic and carcinogenic chemi-cals. These uncertainties create difficulties inidentifying effective, but balanced managementresponses for particular substances or types ofsubstance.

PROGRESS TOWARDS IMPROVING THESITUATION

For each of the problem areas raised above, activityis underway which is aimed at improving the situ-ation. These are discussed in turn below:

1. More data. The International Council of ChemicalAssociations (ICCA) has committed itself to aninitiative whereby a standard ‘baseline’ set of toxi-cological data will be gathered and furnished tothe international community for all those sub-stances marketed in the largest quantities aroundthe world (the ‘High Production Volume’ [HPV]substances, marketed in quantities exceeding 1000tonnes per annum). The dataset generated will beequivalent to the Screening Information Data Set(SIDS) of the OECD HPV SIDS programme andit is planned that the ICCA-generated assessmentswill feed into this OECD programme, the objectbeing thereby to arrive at an internationallyagreed, internationally available assessment of atleast some of the basic toxicological character-istics of all HPV substances. Targets have beenset of producing such assessments for 1000 HPVsubstances by 2004 and all 4100 identified HPVsubstances by 2015.This initiative, if delivered,should build on pre-existing programmes in theEU (e.g. Existing Substances Regulation) andUSA to produce a significant improvement inappreciation of some of the toxicological proper-ties of the most abundant chemical substances inworkplaces around the world.

2. Harmonising positions on data interpretation.Almost a decade ago, the UNCED ‘Earth Summit’held in Rio de Janeiro developed ‘Agenda 21’,Chapter 19 of which set out six Programme Areas(A–F) comprising a range of aspects of globalchemicals management for which improvementswere to be sought through international collabor-ation (UNCED, 1992).One element covered in Pro-gramme Area A is the aim of pursuing global har-monisation of approaches to risk assessment for thepotential effects of chemicals on human health. Pro-gress towards this goal has been relatively slow, butin recent years there have been a number of initiat-ives bringing together those involved in such riskassessment activity from industrial, academic andregulatory instructions world-wide, in pursuit of thedevelopment of greater clarity and mutual under-standing of the various approaches taken and atti-tudes adopted. The value of one document that hasemerged (‘Conceptual Framework for Evaluating aPostulated Mode-of-Action’ [for carcinogenicity]),aimed at achieving common, universal standards inthe structured laying out of evidence on the mode-of-action of an experimental animal carcinogen andthe interpretation of its relevance for human health,is currently being tested by various institutionsaround the world.

293Sharing toxicological information on industrial chemicals

3. Better transfer of toxicological information tothose exposed. Programme Area B of Agenda 21,Chapter 19 sets out the objective of producing aglobally harmonised hazard classification system,and compatible labelling system, for all substancesand preparations thereof, by the year 2000. In thelast five years much of the necessary technicalwork to underpin such a global system has beencompleted. However, it must be acknowledgedthat substantial practical and political problemsremain to be overcome before one common, globalclassification and labelling system becomes areality.In relation to the other principal means ofcommunicating toxicological information, theMSDS, the UK HSE has recently completed areport (‘The purpose, value and utility of toxico-logical information in Safety Data Sheets’) whichis part of an ongoing project known as the ‘3Rs’initiative (getting the right information to the rightpeople in the right way). This project, which stillhas some time to run, is aimed at securing a rangeof improvements in the way in which people inindustry receive information essential for theirhealth and safety. Other groups have also analysedand found fault with MSDSs, and have made vari-ous suggestions for their improvement. It remainsto be seen whether or not these initiatives will beconverted into real advances.

4. More efficient use of the available regulatory andstandard-setting toxicological resources. Slow butcontinuing progress is being made in terms ofthose institutions with the resources to producehigh quality, critical assessments of the toxicologyof industrial chemicals sharing such assessmentswith others and working co-operatively. UKexperience is that in substance assessment for thepurposes of setting occupational exposure limits,links between the technical groups involved con-tinue to develop, with the ACGIH, UK, Dutch,German, Scandinavian and Australian groups nowregularly exchanging documentation (for eachother’s use), future programmes and interpret-ational information.The International Programmeon Chemical Safety (IPCS) programme to generateCICADs (Concise International Chemical Assess-ment Documents) is also now quite well estab-lished, under Agenda 21, Chapter 19, ProgrammeArea A. This programme is directed at convertingextensive substance-specific toxicological assess-ments produced for national purposes into concise,internationally accepted and internationally avail-able documents, which spread throughout bothdeveloped and developing countries a succinct,accurate and up-to-date toxicological picture forsubstances of global relevance. A steady flow ofCICAD production has been sustained in the lasttwo or three years.

5. Improved, shared understanding of the science.One initiative which is underway is the organis-

ing of the World Occupational Exposure Values(WOEV) Symposium in Brussels in November2001. The stated mission of the Symposium is tobring together those with an interest in the scien-tific basis for occupational exposure limit values;to address common themes relating to theirdevelopment; to spread awareness of the workbeing carried forward; and to establish ongoingnetworks of interested parties. The Symposiumwill also bring occupational exposure-limit set-ting bodies together to achieve internationalcooperation on the scientific and technical issuesinvolved. The Symposium hopes to be successfulin its aims:� To address scientific and technical issues rela-

tive to exposure limits for chemical substances.� To identify key criteria used by organisations

worldwide for the setting of limit values andto make transparent important differences.

� To explore the new challenges which need tobe met by limit-setting bodies.

� To identify areas where collaboration at aninternational level can be of mutual benefit.

IMPLICATIONS

All this presents opportunities and challenges to allthose involved and to the world occupational hygienecommunity. In particular, bodies setting standardswill need to ensure that their recommendations arebased on the best available data and remain valid. Forthis ambitious goal to be realised, several things willneed to happen:

� There simply must be greater international collab-oration in this work, with a structure to facilitatesuch collaboration.

� The critical assessment documentation producedby the available resources around the world mustbe structured and extensive enough to be fit forthis international purpose. What is viewed as themost appropriate balance between risk, cost, andsocial and other factors will inevitably varybetween countries. To be of maximum help in thisbalancing, the technical picture available must beclear.

� Even if not developing their own occupationalexposure limits, users of them — professional orperhaps governmental — must understand theirderivation and be equipped to make a sensibledecision about any prevailing situation they arefacing, in comparison with such limits.

� The state of available toxicological knowledgeon a substance at any one specified time needsto be clearly established. This must includeindicating significant absences of data. Withoutthis the process of assessment cannot be trans-

294 P. Oldershaw and S. Fairhurst

parent to future users of the output of suchassessments.

� In the derivation of any standard, alongside thetoxicological picture available at the time theextent to which practicability is taken into accountmust be explicit.

� The scientific terminology used in the assessmentand limit-setting process needs agreement, codifi-cation, and expression in a way to meet the needsof all users.

� For the derivation of a toxicologically based stan-dard the individual steps and deliberations of theextrapolation procedure should be clearlydescribed. In doing so, transparency and mutual

acceptance is enhanced.

REFERENCES

Anon. Toxicity testing: strategies to determine needs and pri-orities. Washington, DC: National Academy of Sciences, 1984.

Allanou R, Hansen BJ, van der Bilt Y. Public availability ofdata on EU high production volume chemicals. EUR 18996EN. Ispra, Italy: European Chemicals Bureau, 2000.

UNCED. United Nations Conference on Environment andDevelopment, Rio de Janeiro, 1992. United Nations, Switz-erland, 1992.

USEPA. EPA analysis of test data availability for HPV chemi-cals. US Environmental Protection Agency, 1998.