EMD545b Lecture #7 Controls in Biosafety III

1. EMD545b Lecture #7Controls in Biosafety III Decontamination and Emergency Response

2. Decontamination • Encompasses: • antisepsis, disinfection, decontamination, and sterilization • Antisepsis • chemical applied to living tissue that will control or arrest the growth of a microorganism • Decontamination • disinfection or sterilization of contaminated materials

3. Decontamination • Disinfection • To free from infection, reduction of contaminant load to a safe level, does not imply total destruction of all microorganisms. Will not always destroy spores. • Sterilization • The destruction of all forms of microbial life. Difficult to achieve (usually referred to a very low chance that a microbe survived).

4. Disinfection in Healthcare • High-Level Disinfection • sporicidal/tuberculocidal (but used for shorter times than required for sterility). Equipment that will have invasive contact with patient. • Intermediate • tuberculocidal (equipment that will contact mucous membranes of patient) • Low-level (kills vegetative bacteria) • for non-critical equipment (no invasive contact)

5. Sterilants - Physical Methods • Steam Autoclave • steam under pressure --> moist heat • 121 C/250 F @ 15 psi for 30 - 60 minutes • Dry Heat • 160 - 170 C/320 - 356 F for 2 - 4 hours • Incineration • 2 stage burn, 1400 & 1800 F

6. Sterilants - Gases • Formaldehyde gas • heat formalin to vaporize it (1 ml/ft^3) • heat paraformaldehyde (0.3 g/ft^3) • 2 hour exposure time required (8 hour or overnight contact period recommended) • can neutralize HCHO (toxic, suspect carcinogen) with ammonium bicarbonate • room temperature > 70 F, %RH - > 70%

7. Sterilants - Gases • Ethylene Oxide • 400 - 800 mg/L • 35 - 60 C temperature, 30 - 60% RH • contact time up to 4 hours • Hydrogen Peroxide • vaporize from 30% H2O2

8. Liquid Disinfectants • Surface treatment or to treat liquid waste • Inactivate by • coagulation, denaturation, lysis, enzyme inactivation • Factors to consider: • temperature, humidity, pH • contact time, concentration • penetrability • presence of organic material

9. Liquid Disinfectants • Alcohol • Ethanol, Isopropanol ( 70 - 85%) • requires presence of water for protein denaturation • bactericidal (vegetative bacteria) • virucidal (enveloped viruses) • Not sporicidal • Not as effective against non-enveloped viruses) • flammable • low BP, higher evaporation rate, difficult to get 10 minute contact time

10. Liquid Disinfectants • Glutaraldehyde • stable in and stored in acid pH range • activated by adding sodium bicarbonate to elevate pH to > 7.5 (14 day shelf-life) • contact time (10 - 180 minutes) • sporicidal at longer contact times • sterility requires 6 - 10 hours • non-corrosive • effective in presence of organic material

11. Liquid Disinfectants • Formaldehyde (4 - 8 %) • active in alkaline pH range, non-corrosive • effective in presence of organic material • diminished activity in colder temperatures • 10 - 30 minute contact time required • fixative (penetration rate of 8mm/24 hours in tissue specimens) • wide spectrum disinfectant • suspect carcinogen, toxic at low levels

12. Liquid Disinfectants • Phenol (0.2 - 3%) • Not sporicidal, not effective against non-enveloped viruses • Tuberculocidal, fungicidal, bactericidal • not affected by presence of organic material • hard water can affect effectiveness • Toxic, can be absorbed through skin (large spills to skin can be fatal)

13. Liquid Disinfectants • Quaternary Ammonium Compounds (0.1 - 2%) • cationic detergents, very good cleaning agents • inactivated by organic material • bactericidal, algicidal, fungicidal, will destroy enveloped viruses • not tuberculocidal or sporicidal • low-level disinfectant • good for general surfaces and floors • very toxic to eyes (a few drops can lead to blindness)

14. Liquid Disinfectants • Halogens - chlorine (0.01 - 5%) • wide spectrum of activity • acts rapidly at low concentrations (10 - 30 min.) • inactivated by organic material (use more) • will lose chlorine upon exposure to light/air • more cidal at low pH, good at lower temps. • very corrosive

15. Liquid Disinfectants • Halogens - Iodine (0.47%, 75 - 1600 PPM) • inactivated by protein • 1600 PPM inactivates wide spectrum of agents • effective over wide pH range • tuberculocidal, sporicidal • corrosive, will stain, toxic, allergenic • Dilution issue - must follow recommended dilutions for iodophors (or iodophor may not be as effective)

16. Liquid Disinfectants • Hydrogen Peroxide (3% - 25%) • stable, non-toxic, fast acting • 10 - 25% solutions are sporicidal • inactivated by organisms that produce catalase

17. Rank Order of Resistance to Disinfection • Prions • Protozoan cysts • Bacterial spores • Non-enveloped (hydrophilic) viruses • Mycobacteria • Fungal spores, fungi • Vegetative bacteria • Enveloped viruses (lipophillic)

18. Verification of Decontamination • Autoclave tape • time/temperature/date records on chart • Chemical indicators (diack melt pellets) • fuse if temperature reached for at least 1 second • Biological Spore indicators • Bacillus stearothermophillus • Bacillus subtilis var. niger • Manifest for biomedical waste (incineration)

19. Emergency Response • Percutaneous exposure • immediately wash well with soap & water • wash should last 15 minutes • dilution of wound most important, soap & water most readily available cleanser • Notify supervisor (if available) • don’t let this delay medical attention • inform that you are heading to Health Services • ask them to initiate incident report (mail to Health Services later) - start review of incident

20. Emergency Response • Percutaneous exposure • seek medical assistance within 1-2 hours • verify proper cleansing • baseline serum taken, tested initiated if appropriate • post-exposure prophylaxis provided if necessary • counseling offered • Before initiating work: • ensure working sink, soap, paper towels present • suitable disinfectant if used

21. Emergency Response • Facial mucous membrane contact • (eyes, nose, mouth) • wash well in eye wash for 15 minutes • eye wash station checked weekly • flow will hit eyes/face (strength, direction) • clear, clean water • unit can be activated for hands-free operation in 1.5 seconds • hold eyelids open with hands • know location of eyewash and how to use before starting work • vision may be impaired in exposure situation

22. Emergency Response • Aerosol exposure • BL2 • leave lab upon release • Wash wounds, flush face/eyes if exposed, wash hands • post sign, keep area vacated for 20 - 30 minutes to allow aerosols to settle • decontaminate personnel clothing, skin • notify lab supervisor, biosafety, and Health Services if necessary

23. Emergency Response • Aerosol exposure • High risk BL2, BL2+, BL3 • hold breath, drop gloves on floor, and immediately proceed to the anteroom • remove all lab clothing and any personal clothing that may have been contaminated • wash all exposed skin surfaces, hands • post sign to alert of spill

24. Emergency Response • Aerosol exposure • verify airflow direction into lab • call safety, principal investigator • no entry until joint risk assessment with safety • all exposed report to Health Service

25. Exposure Incident Follow-up • documented written report • name, lab, department • date, time, location • description of incident • risk assessment for health services • material involved (biohazard, fixed, etc.) • wounds, visible cuts on person • route of exposure, estimated dose (concentration/volume) • depth of wound

26. Exposure Incident Follow-up • Experience of person involved • safety training records • prior accidents/exposures • Object/items involved • sharps (type, brand, reusable/disposable) • location of needlebox • animals • During preparation/use/disposal/cleaning?

27. Exposure Incident Follow-up • Appropriate onsite response after incident? • wash, report, visit to Health Services • Personal protective equipment worn at time • Engineering controls in use? • What were the safety practices at time? • How is the area decontaminated/cleaned? • What is their plan to prevent recurrence? • What can you add after the review? • Write up new SOP and check periodically

28. Accidents & Illnesses • prompt reporting • immediate medical assistance • serum samples, stool specimens, nasal and skin washings • investigate serious, unusual or extended illnesses

29. Report of seroconversion • examine worker • investigate procedures • revise procedures to eliminate exposure

30. Biohazard Spills • BL1 • can clean immediately w/ basic PPE • Spill in a biosafety cabinet • already contained • can initiate clean-up immediately at all levels • for spills that go into grilles, flood drain pans with disinfectant (ensure that drain is closed) and call safety for evaluation - more extensive decon may be needed

31. Biohazard Spills • BL2 spill (outside containment equipment) • evacuate lab for 20 - 30 minutes • treat exposed, remove lab clothing, wash • post-sign • call safety if exposure risk (airborne) high • defined area on floor, bench? - lab • widespread aerosol throughout room (centrifuge incident) - safety assistance needed

32. Biohazard Spills • BL3 (spill outside containment equipment) • evacuate lab • remove PPE in anteroom (contaminated clothing) • wash/decon all exposed skin surfaces, face & hands • post sign • verify airflow direction • call safety & PI, notify Health Services • lab remains closed until cleared by Safety

33. Spill Decontamination • Spill kit (assembled in advance, kept in BL1, BL2 labs, outside of BL3 labs) • concentrated disinfectant (appropriate for agent in use) • paper towels, biohazard bags • squirt bottle • sharps container, forceps/tongs • lab coat/gown, gloves, utility gloves • full face protection, booties • respiratory protection as required

34. Spill Decontamination • COVER • cover spill area with paper towels • DISINFECT • slowly pour disinfectant around perimeter and into the center of spill area. 10-15 minute contact time. • Clean/disinfect surrounding areas • CLEAN • absorb spill and paper towels and place in biohazard bag. Sharps placed in sharps container. • DISINFECT • spray spill area with disinfectant, allow to air dry

35. Mixed Biohazard Spill • Chemical/biohazard spill • will chemical inactivate the biohazard? • is chemical a listed hazardous or toxic waste? • chemical safety risk assessment (PEL, TLV, exposure routes, chemical PPE) • chemical neutralizers or absorbents used • inactivate biohazard component of waste and discard as hazardous chemical waste • check for incompatibilities with proposed disinfectant

36. Mixed Biohazard Spill • Radioactive/biohazard spill • again, more regulated waste takes precedence • inactivate the biohazard component and discard as radioactive waste • avoid bleach with 125-I (radioiodine gas may be released) • booties required for radioactive spill • Geiger-mueller, Scintillation probes (NaI), Liquid Scintillation Counters to determine scope of radioactive contamination

37. BL3 Emergency Response • Airflow alarm in BL3 lab - work in progress • all work under containment • stop work @ time of alarm, remove outer gloves, verify airflow reversal • if verified, cap all cultures and return to incubator or freezer • decontaminate work surfaces in biosafety cabinet, leave waste inside cabinet, leave cabinet on • remove PPE, leave lab, post “lab down” sign, and notify safety, PI, and maintenance

38. BL3 Spill @ time of Airflow Alarm • Worst-case breach • Verify interlock of supply with exhaust • did supply also shut down? • is air movement neutral and not out of lab? • duct tape around entire door to seal in lab • shut exhaust/supply dampers to/from BL3 lab • if breach, may have to evacuate adjacent rooms, floor, building??? • Rapid notification to safety, PI, maintenance • Why redundancy/emergency power so important in BL3 labs!

39. Non-Ambulatory Researcher in BL3 Lab • Prompt notification • 2 person team approach • good visual access inside the lab • video surveillance • method of communication outside the lab • Consider person and all clothing contaminated • EMT’s w/ PPE enter with support or safety personnel • EMT’s provide medical assistance • Safety or support cuts off/removes/decontaminates PPE and regular clothing • 2 EMT’s outside lab awaiting transfer of patient

40. Non-Ambulatory Researcher in BL3 Lab • Decontaminate EMT’s equipment • may have to buy new supplies (BSL3 stigma) • Evaluate contamination of laboratory • gas decontamination may be required • Level of coordination must be practiced • schedule drills periodically • Always hold a post-incident review (lessons learned) session - will benefit all involved

41. Maintain a spill kit for cleaning biological spills. Keep the spill kit outside the BSL-3 Lab (to prevent contamination of supplies)

42. Biohazard Spills • BSL-3 (spill outside containment equipment) • evacuate lab • remove PPE in anteroom (contaminated clothing) • wash/decon all exposed skin surfaces, face & hands • post sign • verify airflow direction • call safety & PI, notify Health Services • lab remains closed until cleared by Safety

43. Spill Decontamination – BSL-3 • Confine spread of contamination to smallest possible zone • HEPA filtered space? • Exhaust location? Notify Plant Maintenance • Determine extent of contamination within zone • Exposed personnel to Employee Health after decon • Environmental stability of spilled agent? • Is time on your side? Wait it out • Unique requirements for agent? (immunization, PPE – any responders at high risk? • Default to HEPA-filtered PAPR for emergency entry

44. Spill Decontamination – BSL-3 • What is the 99.9% particle clearance time for the BSL-3 Lab in minutes? • Is manual facility chemical decontamination sufficient? Which chemicals are effective? • Determine need for Space Decontamination • How sealed/sealable is the space? • Can you achieve parameters required for space decon? • Select remediation plan with incident commander (EHS, FD, FBI?) – Level A/B/C/D Response? • Are clearance swab samples/air samples required to document destruction?

45. Spill Decontamination (Aerosol release throughout laboratory) • Large area decontamination • Gas decontamination • Formaldehyde, chlorine dioxide, vaporized H202? • Outside vendor? EH&S? • Sealed laboratory? • Liquid Chemical Decontamination • Foggers, sprayers? • Contact time? Biological indicators? • Process verified/lab cleared prior to reuse

46. Spill Decontamination – BSL-3 • Release of a Select Agent from BSL-3 lab? • Immediate agency notifications by RO/ARO • Public Health Risk from release of agent? • Public Affairs Office (EHS Director, CEO) • City/Town Dept. of Public Health • State Dept. of Public Health • CDC? • Lessons learned meeting? • Was response protocol effective? • Identify areas of improvement?

47. Spill Decontamination • COVER • cover spill area with paper towels • DISINFECT • slowly pour disinfectant around perimeter and into the center of spill area. 10-15 minute contact time. • Clean/disinfect surrounding areas • CLEAN • absorb spill and paper towels and place in biohazard bag. Sharps placed in sharps container. • DISINFECT • spray spill area with disinfectant, allow to air dry