Recent achievements in the control of PAH exposure on coke oven ...

More documents

Recommendations

Info

3. The correlat<strong>in</strong>g risk associated with chronic workplace <strong>exposure</strong> at this level is 4 deaths <strong>in</strong>10,000 (1 <strong>in</strong> 2,500) workers accord<strong>in</strong>g to <strong>the</strong> Ne<strong>the</strong>rlands’ 'health-based calculatedoccupational cancer risk values' follow<strong>in</strong>g occupational <strong>exposure</strong> to B[a]P [7].Legislation [8] prescribes that <strong>the</strong>se areas should undergo regular clean<strong>in</strong>g <strong>in</strong>clud<strong>in</strong>g <strong>the</strong>wip<strong>in</strong>g <strong>of</strong> walls and floors.Initial audits and sampl<strong>in</strong>g undertaken at Tata Steel’s UK coke oven plants identifieddifferences <strong>in</strong> availability <strong>of</strong> safe refuges, <strong>the</strong> <strong>control</strong> systems available, <strong>the</strong> ma<strong>in</strong>tenance andclean<strong>in</strong>g regimes, and <strong>the</strong> conditions <strong>of</strong> areas considered safe refuges. Welfare facilities and<strong>of</strong>fices generally conformed to <strong>the</strong> requirements for designation, however, mach<strong>in</strong>e <strong>control</strong>cab<strong>in</strong>s did not, and so <strong>the</strong>se were identified as a priority for upgrad<strong>in</strong>g especially <strong>in</strong> high<strong>exposure</strong> risk areas such as <strong>the</strong> battery top.Immediate recommendations result<strong>in</strong>g from audits <strong>in</strong>volved: implementation or upgrad<strong>in</strong>g <strong>of</strong> air filtration systems replacement <strong>of</strong> w<strong>in</strong>dows and door seals upgrad<strong>in</strong>g <strong>of</strong> air condition<strong>in</strong>g units to motivate operators to keep external doorsclosedA number <strong>of</strong> actions resulted:1. An air filtration unit has been identified for trial tak<strong>in</strong>g <strong>in</strong>to account <strong>the</strong> follow<strong>in</strong>g factors: Must be able to provide adequate protection to allow compliance with <strong>the</strong> TSE CoP. Must <strong>in</strong>corporate high efficiency particulate and charcoal filtration. Must have a sta<strong>in</strong>less steel structure to withstand a coke oven environment. Should be multi-functional to draw <strong>in</strong> air from external source and/or recirculate onvariable speed as required. Spare parts and consumables must be available at short notice <strong>in</strong> case <strong>of</strong>emergencies. Should be situated <strong>in</strong>side <strong>the</strong> cab<strong>in</strong> and be compatible with <strong>the</strong> current electricitysupply. Must be provided with an adequate and effective ma<strong>in</strong>tenance regime <strong>in</strong>clud<strong>in</strong>g filtermedia performance determ<strong>in</strong>ation. The ma<strong>in</strong>tenance regime should be compatible with <strong>the</strong> exist<strong>in</strong>g ma<strong>in</strong>tenancecontract companies. Must be available for supply and <strong>in</strong>stallation to all TS UK sites.2. Potentially suitable vacuum clean<strong>in</strong>g systems have been identified and obta<strong>in</strong>ed for trial toassist with rout<strong>in</strong>e clean<strong>in</strong>g <strong>of</strong> cab<strong>in</strong>s.3. Replacement <strong>of</strong> unsatisfactory cab<strong>in</strong> doors and w<strong>in</strong>dow seals has commenced.4. Air condition<strong>in</strong>g systems have been <strong>in</strong>vestigated and more suitable systems identified.5. Mach<strong>in</strong>e cab<strong>in</strong>s will undergo complete ma<strong>in</strong>tenance prior to <strong>in</strong>stallation <strong>of</strong> <strong>the</strong>se systems.This <strong>in</strong>cludes repairs to doors and w<strong>in</strong>dow seals and ‘box<strong>in</strong>g <strong>in</strong>’ <strong>of</strong> cables to leave smoothsurfaces.With respect to cleanl<strong>in</strong>ess <strong>of</strong> welfare facilities, mess rooms and <strong>of</strong>fices, it is appreciated thata stricter level <strong>of</strong> decontam<strong>in</strong>ation may be required to ensure that <strong>in</strong>advertent <strong>exposure</strong>, suchas <strong>in</strong>gestion, does not occur. To ensure that standards are ma<strong>in</strong>ta<strong>in</strong>ed, clean<strong>in</strong>g regimes arecurrently under review and a strategy has been implemented whereby respiratory protectiveequipment and personal protective equipment is removed as far as possible prior to enter<strong>in</strong>g
<strong>of</strong> <strong>the</strong>se facilities. A ‘wipe test’ and an appropriate guidance value are be<strong>in</strong>g developed toallow rout<strong>in</strong>e monitor<strong>in</strong>g <strong>of</strong> <strong>the</strong> work<strong>in</strong>g environment and effectiveness <strong>of</strong> <strong>the</strong> clean<strong>in</strong>gregimes.Exposure assessments at TSE coke ovensBiological monitor<strong>in</strong>g is an effective way <strong>of</strong> determ<strong>in</strong><strong>in</strong>g <strong>in</strong>dividual <strong>exposure</strong>s to <strong>PAH</strong>s via allpotential routes and ensur<strong>in</strong>g ongo<strong>in</strong>g effectiveness <strong>of</strong> <strong>the</strong> adopted <strong>control</strong> measures.Exposure to <strong>PAH</strong>s are determ<strong>in</strong>ed by measur<strong>in</strong>g a metabolite (1-hydroxypyrene) <strong>of</strong> one <strong>of</strong><strong>the</strong> <strong>PAH</strong> family (pyrene) <strong>in</strong> ur<strong>in</strong>e.The TSE CoP provides an <strong>in</strong>itial biological monitor<strong>in</strong>g guidance value (BMGVs) <strong>of</strong> 4 µmol 1-hydroxypyrene/ mol creat<strong>in</strong><strong>in</strong>e* to correspond with a guidance value set <strong>in</strong> <strong>the</strong> UK by HSE.This is not health based but is a practicable, achievable level set at <strong>the</strong> 90th percentile <strong>of</strong>available biological monitor<strong>in</strong>g results collected from a representative sample <strong>of</strong> workplaceswith good occupational hygiene practices. If a result is greater than <strong>the</strong> BMGV it does notnecessarily mean that ill health will occur, but it does <strong>in</strong>dicate that <strong>control</strong> <strong>of</strong> <strong>exposure</strong> maynot be adequate or that an <strong>in</strong>dividual’s work<strong>in</strong>g methods or use <strong>of</strong> <strong>control</strong>s may be below <strong>the</strong>required standard. Under <strong>the</strong>se circumstances employers will need to look at current workpractices to see how <strong>the</strong>y can be improved to reduce <strong>exposure</strong> [9].A fur<strong>the</strong>r <strong>in</strong>-house guidance value has been established by TSE at 2 µmol 1- hydroxypyrene/mol creat<strong>in</strong><strong>in</strong>e. This value is representative <strong>of</strong> very low levels <strong>of</strong> occupational <strong>exposure</strong>consider<strong>in</strong>g <strong>the</strong> background population <strong>in</strong>clud<strong>in</strong>g heavy smokers, and should be achievable ifall <strong>control</strong> measures are adequate and used correctly.Operators employed at <strong>the</strong> coke ovens will be required to undergo biological monitor<strong>in</strong>g aspart <strong>of</strong> <strong>the</strong>ir rout<strong>in</strong>e health surveillance. The frequency <strong>of</strong> monitor<strong>in</strong>g is determ<strong>in</strong>ed by <strong>the</strong>operator’s potential risk <strong>of</strong> <strong>exposure</strong> and <strong>exposure</strong> history. Roll<strong>in</strong>g programmes have beendevised where not already <strong>in</strong> place to ensure ongo<strong>in</strong>g assessment <strong>of</strong> employee’s <strong>exposure</strong>sand efficiency <strong>of</strong> <strong>the</strong> <strong>control</strong>s currently <strong>in</strong> place along with <strong>the</strong>ir ma<strong>in</strong>tenance regimes.* Creat<strong>in</strong><strong>in</strong>e is produced at a constant rate with<strong>in</strong> <strong>the</strong> human body and can be used <strong>in</strong> analysis to correct forde/hydration and normalise results. Conversion: 1mol/mol = 1.93 µg/gResults – Improvements <strong>in</strong> behaviours and reduction <strong>in</strong> <strong>exposure</strong>s due to <strong>control</strong>simplementedThe outcome <strong>of</strong> all <strong>control</strong> measures implemented to date was immediately seen and<strong>in</strong>cluded: Increased awareness and knowledge <strong>of</strong> <strong>the</strong> operators, result<strong>in</strong>g <strong>in</strong> visibleimprovement <strong>in</strong> <strong>the</strong> use <strong>of</strong> available <strong>control</strong> measures <strong>in</strong> behavioural audits. Lower results from biological monitor<strong>in</strong>g, as shown <strong>in</strong> Figs 5 and 6, identify<strong>in</strong>greduced <strong>exposure</strong>s, through all routes, <strong>of</strong> 63.5% (representative average).Demonstration that biological monitor<strong>in</strong>g guidance values can be achieved even <strong>in</strong>employees, who have <strong>the</strong> greatest levels <strong>of</strong> <strong>exposure</strong>, provided <strong>the</strong> <strong>control</strong> measuresare <strong>in</strong> place. Successful collaboration across all TSE coke oven plants. Identification <strong>of</strong> approximately £100k cost sav<strong>in</strong>g opportunities by develop<strong>in</strong>gprotocols for us<strong>in</strong>g shared fan units and issu<strong>in</strong>g personal helmets as RPE options andthrough optimisation <strong>of</strong> filtration change frequency and review <strong>of</strong> exist<strong>in</strong>g hand andsk<strong>in</strong> protection.
Page 1 and 2: Recent ach
Page 3 and 4: Department of Ener
Page 5 and 6: Investigations int
Page 7: Provision of <stro
Page 11 and 12: well beyond 30 years and new <stron

Recent achievements in the control of PAH exposure on coke oven ...

Create successful ePaper yourself

Delete template?

Save as template?