1. U NIVERSITY OF M INNESOTA Dept. of Environmental Health and Safety www.dehs.umn.edu Hazard Analysis Process for Adding Amines to Steam System C. Moody, A. Streifel, and M. Nagel

2. Southeast steam plant

3. Background Peak campus steam demand - 450,000 lb/hr –Hospital demand – 20,000 lb/hr Corrosion of boilers, coils, pumps, traps and piping –Increased maintenance and energy costs – $1M per year

4. Causes of corrosion Corrosion caused by formation of carbonic acid –CO 2 + H 2 O  H + + HCO 3 - (carbonic acid) Major sources of CO 2 –Dissolved gas in make-up water –Thermal breakdown of NaHCO 3 and Na 2 CO 3 Oxygen enhances corrosion

5. Amine addition Add neutralizing amines to keep pH range at 8.5 - 9.2 –Morpholine condenses soon after release to protect close-in piping –Cyclohexylamine protects far reaches of condensate piping

6. Health Effects Eye irritation Irritation of upper respiratory tract Dermatitis and sensitization from skin contact

7. Health standards Amine Type OSHA PEL (ppm) FDA limit in steam (ppm) Odor Threshold (ppm) Morpholine 20100.14 Cyclohexyl- amine 10 0.90

8. NIOSH Health Hazard Evaluations 1982 – Museum study –Diethylaminoethanol (DEAE) produced eye irritation and dermatitis –Air samples - 0.01 ppm 1988 - Electrical components factory –Nausea, dizziness, throat irritation –DEAE and cyclohexylamine added at 4x normal strength 1989- Nurses in humidified nursery & newborn ICU – Eye and upper respiratory irritation –Cyclohexylamine and morpholine

9. NIOSH Evaluation -1993 VA Medical and Research Center Morpholine and cyclohexylamine –Fatigue, allergy symptoms, eye and upper respiratory irritation Air, surface and steam samples –Air samples not exceeding minimum detectable concentrations –Detectable concentrations in surface samples –Measured concentrations in condensed steam samples Recommended no amines for humidification

10. Potential campus exposures Humidification of sensitive patient areas Medical device sterilization Irritation for students and staff when added in excessive amounts to steam Food preparation

11. Control Options for Hospital Clean steam generators Direct steam humidification with monitoring and control

12. Team approach to evaluate proposal Facilities Management Department Contract steam plant operator Department of Environmental Health and Safety

13. Options for amine addition Inject amine based on: –pH of condensate return –Steam demand Grab samples versus real-time monitoring Metered injection

14. Proposal Inject amine based on steam demand –Use computer to calculate injection rate –Use chemical metering pump Install analyzer to continuously monitor downstream concentration Use analyzer signal to prevent overfeed of amine

15. Metering Pump

16. Analyzer

17. Monitor

18. Failure analysis Conduct “What If” analysis based on description of monitoring/control system –Review possible failures –Evaluate control features –Make additional recommendations for monitoring and control

19. What If Analysis What IfConsequences/HazardsSafety FeaturesRecommendations Vendor delivers wrong concentration of solution Amine concentration in steam may not be able to be adjusted by metering pump Certification provided by vendor of amine type and concentration Analyzer detects and adjusts injection rate Certification should accompany the shipment and should be logged in by steam plant staff There is an interruption in steam flow Steam flow interrupted, amine injection continues without interruption, producing excessive amine concentration Control system shuts down amine injection within several seconds None There is a sudden drop in steam demand As aboveAnalyzer continuously monitors the concentration, computes required concentration and makes adjustments to injection pump Target concentration is 1 ppm, but has capacity to deliver up to 10 ppm. Notice and approval of University necessary for increase in dosage.

20. What If Analysis … What IfConsequences/HazardsSafety FeaturesRecommendations Amine concentration exceeds upper setpoint Excess amine in steamDCS system adjusts pump rate down, or shuts down the injection pump depending on excursion; generates operator alarm Connect the alarm point to central monitoring system Test the shut down mode during calibrations Chemical pump failure Pump begins to operate at excess rate Pump leaks On-line analyzer indicates an excursion and shuts down pump Not enough pressure to inject amine None Analyzer failureFalse high concentration signal generated Incorrect low concentration signal generated Analyzer adjusts concentration downward only (fails closed) Analyzer calibrated against laboratory samples of amine blend Take independent samples in critical areas at peak and non-peak steam demand periods

21. Recommendations Certify amine concentration Request written permission of the University to change amine concentration Route alarm conditions to central monitoring point Take independent steam samples

22. Results Real time analyzer –Amine concentrations 1.0 - 2.5 ppm No complaints of irritation or odor

23. Benefits and Conclusions Safety and health assurance –Patients, employees and students Cost effectiveness –Alternative to clean steam generators –Reduce maintenance and energy costs Process hazard analysis useful

25. Craig Moody Craig Moody, CIH Department of Environmental Health and Safety University of Minnesota moody002@umn.edu 612-626-4399 moody002@umn.edu