Office of Pollution Prevention and Toxics 

# Strategies to Reduce Worker Exposure to TCE during Degreasing Expert Public Workshop on Alternatives and Risk Reduction



### Approaches to TCE Use as a Degreaser

July 30, 2014 Presenter: Edward Viveiros (Eastern Research Group, Inc.)1 Office of Pollution Prevention and Toxics 

### • Background • Overview: Degreasing at Commercial Facilities • Technologies That Eliminate or Reduce Risks from TCE 

### • Engineering Controls • Workplace Practices • Personal Protective Equipment • Questions2 Office of Pollution Prevention and Toxics 

### • EPA risk assessment of TCE identified health risks from:

– Commercial and consumer use of TCE as a solvent degreaser

– Commercial use of TCE as a spotting agent at dry- cleaning facilities

– Consumer use of TCE as an arts and crafts spray coating 

### • TCE use concerns:

– Frequent application of TCE at high concentrations

– High potential for human exposure through: • Inhalation (predominant route due to TCE’s volatility) • Skin absorption 

### • To manage TCE risks, EPA developed an outreach document to inform commercial stakeholders of risk reduction options3 Office of Pollution Prevention and Toxics 

### • This guide provides a set of 

### practicable and relevant options for reducing TCE risks • Risk reduction options are based on:

– Literature review

– Interviews with experts4 Office of Pollution Prevention and Toxics 

### • Identifies:

– Typical TCE degreaser use methods

– Typical commercial settings (for targeted communication of risk reduction options) 

### • Addresses four key risk reduction areas:

– Technologies to eliminate or reduce TCE risks

– Engineering controls

– Workplace practices

– Personal protective equipment (PPE)5 Office of Pollution Prevention and Toxics Elimination Substitution Engineering Controls Workplace Practices Personal Protective Equipment 

### • Basis for the key risk reduction areas: the 

### Hierarchy of Hazard Control6 Office of Pollution Prevention and Toxics Elimination Substitution Engineering Controls Workplace Practices Personal Protective Equipment 

### • Basis for the key risk reduction areas: the 

### Hierarchy of Hazard Control Outside of Scope7 Office of Pollution Prevention and Toxics 

# Typical Degreasing Methods8 Office of Pollution Prevention and Toxics 

# Typical Degreasing Methods Spot Cleaning9 Office of Pollution Prevention and Toxics 

### Spot cleaning • Components are cleaned by:

– Spraying degreaser directly onto components

– Wiping with a rag that has been dabbed or soaked in degreaser 

### • This method typically:

– Applies degreasers in excess amounts

– Readily produces TCE vapors during subsequent air drying10 Office of Pollution Prevention and Toxics 

# Typical Degreasing Methods Spot Cleaning Cold Cleaning11 Office of Pollution Prevention and Toxics 

### Cold cleaning • Components are cleaned in a non - boiling (“cold”) solvent • Cleaning occurs by:

– Spraying

– Brushing

– Flushing

– Immersion12 Office of Pollution Prevention and Toxics 

# Typical Degreasing Methods Spot Cleaning Cold Cleaning Vapor Degreasing13 Office of Pollution Prevention and Toxics 

### Vapor degreasing • Degreaser is boiled to produce hot vapors • Components are suspended in the vapor for a set period of time • Vapors gradually condense on the component’s surface, cleaning it in the process14 Office of Pollution Prevention and Toxics 

# Typical Degreaser Users15 Office of Pollution Prevention and Toxics 

# Typical Degreaser Users Repair Shops16 Office of Pollution Prevention and Toxics17 Office of Pollution Prevention and Toxics 

# Typical Degreaser Users Repair Shops Fabrication Shops18 Office of Pollution Prevention and Toxics19 Office of Pollution Prevention and Toxics 

# Typical Degreaser Users Repair Shops Metal Plating Shops 

## Fabrication Shops20 Office of Pollution Prevention and Toxics21 Office of Pollution Prevention and Toxics 

# Typical Degreaser Users Repair Shops Metal Plating Shops 

## Fabrication Shops Electronics Assembly Shops22 Office of Pollution Prevention and Toxics23 Office of Pollution Prevention and Toxics24 Office of Pollution Prevention and Toxics 

### • Available risk reduction options are not exclusive to these shops • Any facility can implement risk reduction options if they use:

– Spot cleaning

– Cold cleaning

– Vapor degreasing25 Office of Pollution Prevention and Toxics Elimination Substitution Engineering Controls Workplace Practices Personal Protective Equipment26 Office of Pollution Prevention and Toxics 

### • For a given shop, the most suitable option can depend on:

– The cleaning process already in use

– The nature of the components being cleaned (material, shape, texture)

– The types of contaminants being removed (oils, greases, dirt, salts)

– The required level of cleaning 

### • Because degreasing processes, settings, and deciding factors are varied, it is difficult for EPA to provide detailed recommendations • Therefore, the guide highlights practicable and relevant technologies 

### that shops can consider implementing • Ultimately, shops must work with vendors to identify the most suitable option27 Office of Pollution Prevention and Toxics 

### Bake-off oven • Applies to automobile, motorcycle, or bicycle repair shops • Decomposes dirt and grease, leaving behind dry residues that 

### can be brushed off • Produces a smaller volume of waste compared to liquid cleaning alternatives (EPA, 1991) • Bake - off ovens can only be used on components that can withstand high heat28 Office of Pollution Prevention and Toxics 

### Water- based cleaning • Applies to any type of shop • Eliminates use of TCE and solvents • Degree of elimination ranges from complete (aqueous cleaning) to partial (semi - aqueous) • Utilizes the following cleaning methods:

– Manual cleaning

– Hot soap washing (hot tank washing)

– Spray cleaning

– Ultrasonic cleaning29 Office of Pollution Prevention and Toxics 

### Low-solids fluxes • Applies to electronics repair and assembly shops • Are used similarly to conventional fluxes • Dry rapidly and leave behind little or no residue, eliminating the need for cleaning with TCE30 Office of Pollution Prevention and Toxics 

### Inert atmosphere soldering • Applies to electronics repair and assembly shops • Soldering occurs in an oxygen -free environment (typically in 

### nitrogen gas) • The inert environment prevents formation of oxide contaminants, eliminating the need for cleaning with TCE • Suitability of this technology is case specific – flux still may be required even if soldering in an inert environment31 Office of Pollution Prevention and Toxics 

### Closed - loop vapor degreasing • Applies to any shop type • Cleans components in an air-tight chamber, which:

– Significantly reduces emissions

– Improves overall cleaning and product quality 

### • Reduces exposures by exhausting vapors before workers can open the chamber door • Reduces vapor emissions by as much as 98% compared to conventional vapor degreasers (NEWMOA, 2001)32 Office of Pollution Prevention and Toxics Elimination Substitution Engineering Controls Workplace Practices Personal Protective Equipment33 Office of Pollution Prevention and Toxics 

### • Mechanical Ventilation

– Removes “dirty” air from within the shop

– Supplies “fresh” air to the shop 

### • Local exhaust ventilation

– Provides exhaust ventilation close to the cleaning station

– Captures and removes TCE vapors surrounding the source, before they enter other areas of the shop 

### • Because of the direct nature of spot cleaning, engineering control options for preventing direct contact with TCE are limited to ventilation34 Office of Pollution Prevention and Toxics 

### • Limit escape of TCE vapors from cleaning tank by:

– Installing vapor-tight covers (rolling covers are preferable since hinged covers can expel TCE vapors when they swing closed)

– Covering solvent bath with a 2 - to 4- in water layer (EPA, 1981)

– Installing lateral exhaust systems (large cleaning tanks only; exhausts should pass through carbon adsorption unit to reduce shop emissions) 

### • If using spray equipment, consider:

– Using a solid -fluid stream sprayer

– Avoiding atomizing or shower sprayers (they generate more TCE vapors)35 Office of Pollution Prevention and Toxics 

### • Limit escape of TCE vapors from degreaser by:

– Installing vapor-tight covers (rolling covers are preferable since hinged covers can expel TCE vapors when they swing closed)

– Installing a second set of cooling coils (“freeboard chillers”)

– Installing lateral exhaust systems (large cleaning tanks only; exhausts should pass through carbon adsorption unit to reduce shop emissions)

– Installing a pressure gauge to identify leaks (air-tight systems only)36 Office of Pollution Prevention and Toxics 

### • Limit escape of TCE vapors from degreaser by:

– Installing vapor-tight covers (rolling covers are preferable since hinged covers can expel TCE vapors when they swing closed)

– Installing a second set of cooling coils (“freeboard chillers”)

– Installing lateral exhaust systems (large cleaning tanks only; exhausts should pass through carbon adsorption unit to reduce shop emissions)

– Installing a pressure gauge to identify leaks (air-tight systems only) 

### • Where feasible, consider using automated controls:

– Condenser coolant thermostat switch

– Solvent level control switch

– Vapor level control switch37 Office of Pollution Prevention and Toxics Elimination Substitution Engineering Controls Workplace Practices Personal Protective Equipment38 Office of Pollution Prevention and Toxics 

### • Isolate cleaning activities — physically separate the cleaning 

### station from the rest of the shop • Establish guidelines on when it is absolutely necessary to clean components with TCE; prohibit its use otherwise • Encourage or require employees to brush or scrape off caked on solids prior to cleaning components39 Office of Pollution Prevention and Toxics 

### • Keep tank/degreaser covers closed whenever possible • Rack components in a manner that minimizes drag- out losses • Drain cleaned components for at least 15 seconds or until 

### dripping stops • Avoid subjecting degreasing station to drafts (they can carry TCE vapors into surroundings) • Maintain an appropriate freeboard ratio (75% for cold cleaners, 100% for vapor cleaners) (KSUPPI, 2010)40 Office of Pollution Prevention and Toxics Elimination Substitution Engineering Controls Workplace Practices Personal Protective Equipment41 Office of Pollution Prevention and Toxics 

### • PPE that can effectively protect skin against TCE

– Gloves

– Coveralls 

### • Specific materials and brands are listed in the guide42 Office of Pollution Prevention and Toxics 

### • Wear chemical splash 

### goggles to protect eyes against any splashing
• Wear face shield over goggles to provide extra protection43 Office of Pollution Prevention and Toxics 

### • Provide eye wash stations 

### near degreasing areas • Ensure unobstructed access • When exposed, rinse eyes for at least 15 minutes44 Office of Pollution Prevention and Toxics 

### • Most effective respirators for TCE 

### include:

– Full -facepiece respirators with positive pressure supplied air

– Self- contained breathing apparatus 

### • These respirators have an assigned protection factor (APF) of 10,000 (NIOSH, 2011) 

### • Dust masks (N95 respirators) do not protect against TCE45 Office of Pollution Prevention and Toxics 

# Questions?46 Office of Pollution Prevention and Toxics (EPA, 1981) Solvent Degreasing. AP -42 – Compilation of Air Pollutant Emission

Factors. Vol. 1. Fifth Ed. U.S. Environmental Protection Agency. 1981. (EPA, 1991) Guides to Pollution Prevention — The Automotive Repair Industry. U.S.

Environmental Protection Agency. 1991. (KSUPPI, 2010) The Smell of Success: Decreasing Air Pollution in the Kansas City Area.

Kansas State University Pollution Prevention Institute. 2010. (NEWMOA, 2001) Pollution Prevention Technology Profile – Closed Loop Vapor Degreasing.

Northeast Waste Management Officials’ Association. 2001. (NIOSH, 2011) Trichloroethylene. NIOSH Pocket Guide to Chemical Hazards. National

Institute for Occupational Safety and Health. 2011. (NJDH, 2008) Right to Know Hazardous Substance Fact Sheet: Trichloroethylene. New

Jersey Department of Health. 2008.