# Spray **Polyurethane Processes** 

Daniel Almaguer, M.S. Kathleen Ernst

Disclaimer: The findings and conclusions in this presentation are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health (NIOSH). Mention of com

pany nam es or products does not constitute endorsem ent by the Centers for Disease Control and Prevention (CDC) or NIOSH.

# Who is NIOSH?

 Created under the OSHAct of 1970  **Mission** - To ensure safety and health at work for all people through research and prevention.  Responsible for conducting occupational safety and health research.  Education and Training. 

###  To provide leadership in research to prevent work - related illness, injury, disability, and death.

# DART **- EPHB**  Division of Applied Research & Technology (DART) Engineering & Physical Hazards Branch (EPHB)  Conduct research on engineering controls (e.g. ventilation) to reduce exposures to hazardous agents.  Engineers, Industrial Hygienists  Identify, evaluate, design and disseminate information on engineering controls.

# Spray **Polyurethanes Usage** 

 Products  Flexible foams  Rigid foams  Coatings  Adhesives  Industries  Construction  Tanks and Pipes  Bedding  Adhesives  Sealants  Elastomers  Binders  Bedding  Furniture  Appliance  Electronics  Wheels and tires  Packaging  Textiles and Fibers

# Polyurethanes **= Isocyanates**

 Isocyanates - highly reactive compounds containing the isocyanate group ( - NCO)  Isocyanates react readily with alcohol ( - OH or hydroxyl) groups to produce polyurethane polymers  Isocyanates are one of the raw materials from which polyurethane materials are made.

# What is the Concern/Problem?

 Isocyanates are the leading attributable chemical cause of occupational asthma in the United States and many other industrialized countries

 Workers with asthmatic symptoms from isocyanate exposure often continue to have symptoms even after exposures have ended.

 Affected workers often have to leave their jobs to prevent further progression of respiratory symptoms.

# MDI Health Effects

 Health effects result from inhalation and skin exposures.  Irritation and Lung Injury  Respiratory Sensitization  Dermal Sensitization  Acute exposure for some sensitized individuals may prove fatal ( **Feb. 2003** ).

## Spray Polyurethane Foam

**Insulation (SPF)**  **NIOSH has not conducted**  **a study of SPF insulation**  **process.**  NIOSH has conducted a comprehensive study of the TBL process.  NIOSH has conducted a review of industry information on the SPF insulation process.  Presentation of what we know about the two processes.

## NIOSH Truck Bed **- Liner (TBL)**  **Study**

 Identify shops with help of major companies.  Assessed MDI exposures in TBL shops.  PBZ and area sampling for MDI.  Airflow measurements and evaluation of LEV. 

###  Evaluated spray booths and LEV systems to identify the best controls.  Recommended control strategies including engineering control design.

# NIOSH TBL Study (cont.)

 Designed improved LEV system for spray on bed - liner shops. CPI has also designed improved LEV.  Compare isocyanate sampling methods: filter cassette vs. impinger/cassette.  Disseminate information.  TBL Alert  TBL PPE Poster

## MDI used in both TBL and SPF

 Methylenebis(phenyl isocyanate) [MDI] is used in both the TBL and SPF insulation processes.  Studies show MDI in these two processes exceed the OELs.  Heated product will result in increased airborne MDI concentrations.

## TBL and SPF Insulation Processes **Two Part Chemical Application**   Part A

– Isocyanate  MDI  pMDI  Part B

– Polyol Resin  Amine catalyst  SPF has a blowing agent **Applied w ith**  **hand -**  **held spray gun using pressuriz**  **ed system**

# Isocyanate **Mixing and Curing**

Component A (Isocyanate) Mix Polyurethane **Cure time?** Component B (Resin) Mix

TBL - Isocyanate component is almost always added in excess to the mix to ensure a complete reaction. **SPF?**

## Dermal Hazards before spraying

**(Applies to both TBL and SPF)** 

 Absorption of isocyanates through skin  Can lead to sensitization  Contamination and cross contamination of work surfaces can occur . Employees are exposed to the raw isocyanates handling opened containers and setting up equipment.

## Hazards During Spraying

**(TBL and SPF Spray Gun User)**

 Inhalation and skin absorption  MDI droplets in spray aerosol  Increased MDI vapor from exothermic reaction SPF process has additional workers in the area during spraying

## TBL Real Time Aerosol Spray **Highly Variable Concentrations**

3 4 5 6**R e** **l a** **t i** **v e** **C o** **n c** **( m** **g /** **m 3** **)**

0 1 213:30:1313:31:0413:31:5513:32:4613:33:3713:34:2813:35:1913:36:1013:37:0113:37:5213:38:4313:39:3413:40:2513:41:1613:42:0713:42:5813:43:4913:44:4013:45:3113:46:2213:47:1313:48:0413:48:5513:49:4613:50:3713:51:2813:52:1913:53:1013:54:0113:54:5213:55:4313:56:3413:57:2513:58:1613:59:0713:59:5814:00:4914:01:4014:02:3114:03:2214:04:1314:05:0414:05:55 **Ti me**  **( h:**  **m: s)** **R e** **l a** **t i** **v e** **C o** **n c** **( m** **g /** **m 3** **)**

**Unknown in SPF** 

**pr ocess**  **– hazdust**  **particle counter**  **used to collect**  **re altime**  **data, not specific for**  **MDI**

## Sampling Pump/Media

**for MDI Aerosols**

**NIOSH TBL** 

**Study compar ed impinger**  **s ampling**  **method with filter**

**m ethod. Results indicated**  **impingers captur**  **ed levels of MDI 2**  **- 5 times**  **higher than filters** 

## NIOSH TBL Study Results vs. **Canadian SPF Insulation Results** 

 TBL samples collected at six shops.  Canadians SPF

– five sites  MDI monomer samples ranged up to 5.4 mg/m 3  Canadian SPF

– 2.1 mg/m 3  Canadian SPF

– 2.1 mg/m 3

 **NIOSH REL** = **0.2 mg/m 3**  **; 15 -**  **min. ceiling**

= 0. 02 mg/m 3 ; 8 - 10 hour TWA  OSHA PEL = 0.2 mg/m 3 ; 10 - min. ceiling

# Other SPF Chemicals of

**concern**

 Amine catalysts

– considered proprietary in many cases  Blowing agent

# Spray **Booth Results**

 Samples exceeded NIOSH REL  by 3 to 27 times the REL  Canadian study - SPF exceed REL by 10.5x



###  Always wear PPE, full - face respirator, and use exhaust ventilation when spraying.

# Preparation **Area Results**

 **Samples collected outside spray area/enclosure**  **To assess ventilation and integrity**  **of enclosure**  **Below N**  **IOSH REL**  **But, some samples show ed**  **detectable concentrations**   **Results document MDI is escaping enclosures**

 **Basis for Recommending**  **enclosing spray area**

**– Isolate the SPF spray area** 

# Exhaust **Results**

 **Detectable MDI concentrations w ere**  **found at some exhaust locations.**   **Sample location and w ind**  **direction possibly affected results, giving “non**  **- detect” reading.** 

 **Exhaust to unoccupied area.**  **Prevent access to exhaust area.**  **Does exhaust need to be filtered? discussion/research**  **needed**

# Post Spray **Results**

 **Detectable MDI concentrations in booth**  **All below N**  **IOSH REL**  **15 -**  **30 minutes TWA samples: concentrations**  **higher at the beginning of the sample period**

 **Assessment of SPF needed to determine w hen**  **it is safe to re**  **- enter and/or re**  **- occupy area.**   **Do not re -**  **enter booth w ithout**  **PPE. Minimum**  **needed is full -**  **face APR w ith**  **HEPA filters and**  **chemical protective clothing to protect skin.**

# TBL Recommendations **for**

**Worker Protection** 

# NIOSH TBL Alert **- 2006**  **Contains Recommendations for:**  **Workers**  **Employers**  **Future Research**  **Engineering controls**  **Exposure monitoring**  **Respiratory protection**  **Medical monitoring**   **Surveillance**  **Decontamination**

## GOT EVERYTHING COVERED?

**Keep yourself working**  **safe by reading these helpful**  **tips each day**

**befor e**  **spraying...........**  To protect my lungs, wear a full - face supplied - air respirator  To help me see and to keep mask clean, use a peel - of f shield  To protect my skin, wear a full - bodied suit and **after spraying..............**   Remember to wash my hands and face before eating and drinking  If I experience symptoms, such as shortness of breath or skin irritation, tell my supervisor and my doctor

 To protect my skin, wear a full - bodied suit and chemical - resistant gloves  To keep the ventilation system operating at its best, make sure the filters are clean

## GOT EVERYTHING COVERED? For more information on protecting yourself from the hazards of isocyanate exposure during spray - on truck bedliner application: Contact the National Institute for Occupational Safety and Health at 1 - 800 - CDC - INFO (1 - 800 - 232 - 4636) Also visit the NIOSH Isocyanate Topic Page at http://www.cdc.gov/niosh/topics/isocyanates/ **DEPARTMENT OF HEALTH AND**  **HUMAN SERVICES**  Centers for Disease Control and Prevention National Institute for Occupational Safety and Health DHHS (NIOSH) Publication No. 2008 - 109

# TBL Recommendations

 Use Personal Protective Equipment (PPE) and respirator - Applies to SPF  Enclose the spray booth

**– SPF isolate**  **area to ensure others are not exposed**   Provide adequate exhaust ventilation to remove MDI **– SPF explore w**  **ays to safely exhaust**  Limit access to spray area - Applies to SPF  Exhaust through roof and prevent access - SPF prevent access to exhaust area  Do not re - enter booth without PPE - SPF spray area

## Protective **Clothing and Equipment**

**(TBL and SPF)** 

 Full - face supplied air respirator. * NIOSH

- approved supplied - air respirator with a full facepiece operated in a pressure demand or other positive - pressure mode  Supply air must come from uncontaminated area  Chemical protective clothing to protect skin  Hooded respirators acceptable if tested and certified to meet higher APF of 1000

# Eye **and Face Protection**

 Vapors of diisocyanates are corrosive and severely damaging to the eyes. Contact may cause permanent eye damage.

# Hand and Skin Protection

 Protective equipment such as gloves and faceshields must be worn to protect skin.  Double glove  Use tools, such as spatulas, to avoid skin contact.  Treat outside of containers as contaminated.

# Hand and Skin Protection **(cont.)**

 Protective clothing (coveralls, gloves, booties) should be made of a material resistant to isocyanates.  Gloves:  Butyl rubber gives the best protection.  Nitrile rubber, chlorinated polyethylene, and polyvinyl alcohol provide adequate protection for short term exposure.

 **Even the most resistant materials**  **may be penetrated quickly**  **and should be replaced often.**

# Work **Practice Controls** 

 Contaminated clothing and equipment should be decontaminated before it is reused.  For example: a solution of 90% water, 3 - 8% ammonia and 2% liquid detergent.  Do not take contaminated work clothing home.  Eyewash fountains should be provided in the immediate work area for emergency use.  Do not eat, smoke or drink where isocyanates are handled, processed or stored.  Wash hands carefully before eating, drinking, smoking or going to the washroom.

# Medical **Surveillance**

 A physical examination , including an occupational and medical history, at the beginning of employment.  Lung function tests and history of asthma, bronchitis, emphysema, allergies, or other breathing problems.  Yearly follow - up examinations , including lung function tests at the beginning and end of a single shift or work week.  See a pulmonary specialist if symptoms from isocyanate exposure develop.

# Enclosure **Design** *

 Isolate the spray process

– Applies to SPF .  Build a spray enclosure to contain airborne MDI within the enclosure.  **WARNING** : This will result in increased concentrations within the enclosure, so the enclosure will need exhaust ventilation  Limit physical dimensions of the enclosure to the smallest floor area and room volume compatible with the spray operation to maximize the efficiency of the ventilation system. *** CPI -**  **Website has information on TBL enclosures** 

# Ventilation **of Spray Enclosure**

 Provide exhaust ventilation to capture vapor and particulate MDI near the point of generation.  SPF explore use of air movers to exhaust, every space would be different;  Clean up of residual dust from trimming is an issue;  Ensure exhaust area is clearly labeled;  Prevent access to exhaust area.  Provide make - up air for the enclosure.  Balance supply air and exhaust air to ensure that the spray enclosure is under negative pressure.  **For SPF process this needs to be studied or assessed.**   **Assessment of blowing agent and amine catalyst needed** 

## Ventilation **of Spray Enclosure**

**(cont.)**

 The exhaust rate should be based on the physical dimensions of the spray enclosure and provide a minimum of 6 air changes per hour.

 Make - up air supply and exhaust should be located up air supply and exhaust should be located to generate a directed air flow that maximizes ventilation efficiency and contaminant control.

 **For the SPF process this needs to be studied**

## Ventilation **of Spray Enclosure**

**(cont.)**

 Discharge the exhaust air through the roof.  Locate exhaust stack away from air intakes, garage doors, or other openings where the exhaust could re - enter the shop or other occupied areas.  Ensure exhaust is discharged above the roof recirculation region (See Industrial Ventilation: A Manual of Recommended Practice [ACGIH 2004] to determine the recirculation region).  Control access to exhaust discharge areas by physical barrier and warning signs.  **Needs to be assessed for the SPF process.**

# Implementation **GAP Hierarchy**  **of controls**

 Elimination  Substitution - replace high hazard with low hazard  Engineering

– ventilation, enclosure  Protective Clothing and Equipment - respirators, ear plugs, gloves  Administrative - training, procedures, policy  **Gap betw een**  **wh at**  **we kno**  **w and w**  **hat the**  **wo rker**  **does.**

# Initial Assessment **of SPF**

 The industry has a wealth of Information on spray polyurethane products.  Indications that the information is not consistently reaching the worker.  We need to work collaboratively to protect the health of the SPF workforce.  Develop a series of messages for the worker  Ensure that correct information gets to the workers

# Sources **of OS&H Information**

 NIOSH Website: **www.cdc.gov/NIOSH**  **NIOSH 800**  **Number --**  **1 -**  **800 -**  **CDC -**  **INFO**  OSHA Website: **www.osha.gov**  Manufacturers or Product Distributors  Center for the Polyurethanes Industry website

– **www.polyurethane.org**

– many publications on MDI and other isocyanates.

# Contact **Information Daniel Almaguer, MS**  **NIOSH Division**  **of Applied Research and Technology Engineering and Physical Haz**  **ards Branch 4676**  **Columbia Parkw ay,**  **Mailstop R -**  **5 Cincinnati, Ohio 45226**  **Phone: (513) 841 -**  **4221 FAX: (513) 841**  **- 4506**