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Mirrico Seminar, Kazan, September 2011 Paul Wood and Anna Vatsurina. Outline. Learnings from an incident Review Risk, Hazard and Exposure Exposure issues Examples of how Dow Microbial Control, controls exposure to biocides Packaging Labelling Safe Removal Transport Lab Safety Storage
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Mirrico Seminar, Kazan, September 2011Paul Wood and Anna Vatsurina
Outline • Learnings from an incident • Review Risk, Hazard and Exposure • Exposure issues • Examples of how Dow Microbial Control, controls exposure to biocides • Packaging • Labelling • Safe Removal • Transport • Lab Safety • Storage • Dosing • Suggestions • Conclusions
Everyone Learns from an Incident Biocides are not dangerous when handled correctly
Chemical Handling: Level of Risk Two factors to determine the risk when handling a chemical • Hazard Type or Consequence of Exposure • Corrosive = will cause burns (contact may not be detected immediately) • Toxic = a poison • Respiratory irritant = like household bleach or ammonia • Skin sensitizers = cause “skin allergy” • Exposure Potential or Likelihood of Event • How much product ? • Probability of an exposure ?
Level of Risk Hazard x Exposure Potential = Risk Priority in hazard management reduces the exposure potential = x Ethanol Safe Hazard = HIGHLOW LOW Unsafe Ethanol = x Hazard = HIGH HIGHHIGH
Ingestion Inhalation Skin Exposure Potential How do we come into contact with a chemical ? • There are many routes to exposure
Gloves left lying on the floor Water collecting on top of a drum Contaminated cleaning cloth left in a bin Opening, moving, connecting / disconnecting, emptying apparently “Empty” drums Containers used for hazardous materials without labels Cleaning / repair of contaminated installations Door handles / Doors opened by someone wearing gloves Types of Workplace Exposure Exposure to biocide residues
Spills from damaged packaging, or pipe work Dosing from drums, or pails manually Decanting from drums, or pails into smaller vessels Using samples Collecting samples from the production process Taking samples for Quality Control of raw materials Samples shipped to customers Handling samples in the lab. Types of Workplace Exposure Exposure to liquid biocides
Perform a hazard- and safety analysis of the intended task according to your internal rules ( EHS review ) Follow the recommendations on MSDS* and Labels Exposure Control If there is the potential for exposure • Industrial Hygiene / Cleanliness and Housekeeping • Working Instruction • Spill-/Leakage Handling • Emergency Procedures • Training !!! • Installations and tools you intend to use for the planned task • PPE (Personal Protective Equipment): type and control intervals • Appropriate ventilation of the working place / area • Safety installations: Safety Showers / Eye rinsing stations
Biocide Packaging Packaging has to be designed to be safe • Containers • Have to be UN approved • 3H1/Y1.4/150/** GB/3380 • Stringent testing • Drop tested • Are fitted with tamper evident seals for security reasons • Are palletised to prevent damage • The number of drums are limited on a pallet to prevent overhang and restrict weight • Packaging ergonomics
Signs placed around the workplace inform operators on which and when personal protective equipment should be worn in specific areas In addition use educational posters as part of an on-going safety education program On Site Signs & Labelling Product labelling is one source of information but there are others…
Helmet • Goggles • Suit • Gloves • Rubber Overshoes Personal Protective Equipment ( PPE )
Lab Safety To avoid mishandling and accidents Always ensure samples are clearly labelled Warning symbols are visible Store products in clearly labelled cabinets To prevent exposure during use Handle biocides in a fume cupboard Make sure lab technicians wear the correct protective clothing: Gloves Goggles Ensure the area where biocides are handled is kept clean
Warehouse Storage Store biocides safely • To maximise the safety of people • Training • Keep pedestrians separate from product • Safety barriers around offices • Special bins for hazardous waste • Ventilate warehouse • To prevent blind corners, or falling containers • Restrict pallet height • To avoid mishandling • Use painted areas • Good lighting
Suggestions • Be proactive • Review the MSDS and label warnings • Do a safety review of the job • Have a written procedure and follow it • Evaluate and inspect the equipment to be used • Inspect your Personal Protective Equipment • Have the spill deactivation kit equipment and chemicals in place before an incident occurs!
Why use biocides ? Essential To: • Maintain Efficient Heat Exchange • Prevent Corrosion • Prevent Plugging of Orifices • Prevent Potential Health Concerns • Maintain Aesthetic Appearance
Why use biocides ? • Microbes can be: • algae if light reaches the collection basin • aerobic bacteria • anaerobic bacteria (SRB’s) • Moulds and yeast
Bio-films • Microbes can attach to surfaces and produce slime • impairs the heat transfer • induces microbial corrosion (MIC) • clogs filters, screens, casings and nozzles • potentially harboursLegionellapneumophila
Stage 1 Conditioning Layer Stage 2 Bacterial Attachment Stage 3 Slime Formation (EPS Production) Stage 4 Slime Thickening Stage 5 Slime Detachment Biofouling Control – Biofilm Issue • A biofilm is a layer of slime that is produced by microbes after they attach to a surface • Biofilms serve to protect the microbial community that is underneath it • Corrosion and H2S production result from the growth of microbes within a biofilm • Removing biofilm is more difficult than preventing the formation of a biofilm
Examples of “Patchiness” in Bio-films on 316 Stainless Steel
Review of the active ingredients used in indistrial water cycles
Oxidisers • Cl2, HOCl, Br2, HoBr, • Chloramaines ; ClO2, H2O2 / Peracetic acid • Corrosive • Very fast acting • Effect is short-lived – no permanance • Generate high levels of AoX ( adsorbable organic halides )
Glutaraldehyde 1, 5-pentanedial
Glutaraldehyde Features • Quick kill (1-3 hours) under alkaline conditions (pH 7-9) • Broad spectrum efficacy • Highly effective against SRB, biofilm, and Legionella • Readily biodegradable at concentrations < 5-ppm • Compatible with dispersants, surfactants and most WT chemicals, including CMIT/MIT • Compatible with halogens and other WT additives • Does not contain or release formaldehyde • Kills via cross-linking proteins in cell wall
Glutaraldehyde Limitations • Weak efficacy versus fungi and algae • Stability with ammonia (NH3) and alkaline pH • De-activated by bisulphites • Polymerises under alkaline and high temperature conditions (haziness / yellowing) • Evaporation (volatilization) potential increases with temperature and /or aeration
Br H Br N C C H C N O DBNPA 2,2-dibromo-3-nitrilopropionamide Registered Applications • Cooling Water (Re-circulating / Once-through / Open / Closed) • Retort Systems, Pasteurizers • Reverse Osmosis Membranes • Air Scrubbers and Washers • Paper Mills • Additives/Mineral Slurries • Enhanced Oil Recovery • Publicly Owned Treatment Works
DBNPA Features • Extremely fast acting (15 - 60 min) • Broad spectrum efficacy • Highly effective against biofilm and Legionella • Effective at low dose levels • Easy to dose liquid • Non-corrosive at in-use concentration • Low environmental impact • Short half-life at more alkaline pH’s • Kills via reactions with sulphydryls and disruption of respiration and metabolism
DBNPA Limitations • Liquid product shelf life is limited (6 months) • Weak versus fungi and algae • Low solubility in water • Incompatible with strong nucleophiles and reducing agents • Not UV stable • Occasionally referred to as an oxidizer
THPS tetrakis(hydroxymethyl) phosphoniumsulphate
THPS Limitations • Known to release formaldehyde rapidly (25% of total dose) • Cationic properties react with anionic inhibitors • Not compatible with oxidizing biocides • Unstable at high pH • Issues with use of THPS in high calcium waters
CMIT / MIT Registered Applications • Recirculating Cooling Water (Open and Closed) • Air Washers & Industrial Scrubbing • Industrial Process Water • Brewery Pasteurizers and Can Warmers • Industrial Wastewater • RO / UF Membranes (non-medical; non-potable) • Pulp and Paper Slimicide • Additive and Slurry Preservation
CMIT / MIT Features Product Feature Customer Benefit
CMIT / MIT Limitations • Poor stability above pH 9 and >40º C • Poor stability with nucleophiles and reducing agents (sulphides, sulphites, amines,) • Perceived weakness versus SRB • Slow killing • Safe handling concerns / sensitization / burns • New solid version will address safety issues