1 / 16

Setting the scene

UK Approach to Risk Assessment of Genotoxic Carcinogens in the Occupational Setting Dr Susy Brescia Chemicals Regulation Directorate. Setting the scene.

misha
Download Presentation

Setting the scene

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. UK Approach to Risk Assessment of Genotoxic Carcinogens in the Occupational SettingDr Susy BresciaChemicals Regulation Directorate

  2. Setting the scene • For some chemicals/uses (cosmetics, biocides for the amateur, food additives, etc), mutagenic property sufficient to ban/not authorise use by the general public no risk assessment required; • For industrial/professional uses of chemicals with a mutagenic property, societal position has been not to ban, but to seek to manage the risk risk needs to be considered.

  3. Legal framework for industrial/professional uses of chemicals • Chemical Agents Directive; • Carcinogens Directive; • REACH; • Classification, Labelling and Packaging Regulation;

  4. Genotoxic carcinogens: definition • Induce tumours, increase tumour incidence and/or malignancy or shorten time to tumour occurrence in animals or humans; • Evidence of mutagenic activity in vivo; • Assumption made – genotoxicity key event in mechanism of carcinogenesis

  5. Genotoxic carcinogens: identifiable threshold or not identifiable threshold? • Increasing evidence even directly acting genotoxicants have (rather than can be postulated to have) a biological threshold – difficult to identify experimentally; • Where mechanistic data available and practical dose threshold identified RA according to threshold approach; • Where threshold cannot be identified – we do not know whether a threshold exists (any exposure might carry some risk);

  6. UK approach to RA of non (identifiable)-threshold genotoxic carcinogens • A safe level of exposure cannot be identified; • No attempt to quantify levels of risk; • ALARP: reduce exposure ‘As Low As is Reasonably Practicable’;

  7. UK approach: why no quantification of risks?

  8. ALARP • Not a risk assessment methodology; • Risk management tool; • Emphasis on adequacy of controls to achieve sufficiently low level of exposure at which there could still be a level of cancer risk, but if so, the judgement is that it is low; • To ensure exposure is reduced at the lowest achievable and reasonably practicable level;

  9. Lowest Reasonably Practicable Level • In theory, balance between costs of controls and health benefits; In practice, as no estimation of risks, ALARP has been as low as possible without astronomic costs/closure of business; Or • According to REACH, in principle, level at which socio-economic benefits of the substance outweigh the risks; In practice, as no risk estimation in the UK, difficult to implement it in transparent manner; But • At this level still continuing duty on industry towards improved control

  10. Benefits and disadvantages of ALARP BENEFITS • Simple - based on hazard identification and exposure control; • No concerns about accuracy of risk estimates; • Regulators not forced to defend inaction at “acceptable/tolerable” levels of risks (10-6 is 200 in 20 million); DISADVANTAGES • Not completely transparent; • No absolute reference point – best practice tends to be current practice that is best;

  11. ALARP in practice in the workplace (1) • Elimination/total ban (M+U restriction/REACH restriction from 1 June 09) - technically and economically viable, less hazardous substitutes (underlying principle of CAD, Carc Dir and REACH) REACH Authorisation of nominated SVHCs (including genotoxic carcinogens): Industry to show • Invest in research of safer alternatives; • Develop substitution plan; • Continuing duty to improve controls;

  12. ALARP in practice in the workplace (2) • Very high level of containment - Closed automated systems; - Redesign of the process; - Engineering controls e.g. equipment under negative pressure; - Regularly cleaned and maintained equipment; - PPE (appropriate gloves, respirators and goggles) and LEV for system breaches (sampling, packing, maintenance/repair); But - Some processes less efficient/do not work when enclosed; - Costs for closed systems may be too high for small companies;

  13. ALARP in practice in the workplace (3) • Other measures to control risks - Dust and mist suppression methods (e.g. tablets or pellets rather than powder); - Control of staff to work area; - Change of PPE regularly; - Training of employees in the handling of dangerous chemicals; - Air and biological monitoring to show exposure levels are low and PPE is working; - Health surveillance;

  14. RA of genotoxic carcinogens: some personal thoughts • Unless dramatic scientific advance in developing methods to identify thresholds for genotoxicants, regulatory system has no magic solution to offer; • Both qualitative and quantitative approaches based on assumptions and not facts – hence inherently faulty; Question • From what we know today on the mechanisms of gentoxicity, is it time to push the boundaries?

  15. Is there a satisfactory alternative to ALARP?

  16. THANK YOU

More Related