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### Memorandum To: Docket EPA - HQ - OAR- 201 4 - 019 8 From: Margaret Sheppard

EPA/Stratospheric Protection Division Subject: In formation on workplace exposure limits for foam blowing agents Date: July

7 , 2014 This document summarizes information on workplace exposure limits for foam blowing agents mentioned in the preamble to the proposed rule, “ **Protection of Stratospheric Ozone: Change of Listing Status for Certain Substitutes unde**  **r the Sign ificant New Alternatives**  **Policy Program**  . ” Table 1 provides the meaning of a number of abbreviations and terms that will be used later in this document. Table 2 identifies the workplace exposure limits for the foam blowing agents mentioned in the preamble, as well as setting out the foam blowing agents that are acceptable b y end -use. HCFC foam blowing agents are not included here; these foam blowing agent s are re stricted under EPA’s phaseout regulations implementing Section 605(a).

### 2 **Table 1**  **. Explanation of Exposure Limit** **- Related**  **Terminology 1** 

**Organizations Issuing Workplace Exposure Limits Abbreviation**  **Full Name of Organization** OSHA Occupational Safety and Health Administration NI OSH National Institute for Occupational Safety and Health ACGIH American Conference of Governmental Industrial Hygienists AIHA American Industrial Hygiene Association **Workplace Exposure Limits Abbreviation**  **Name of Exposure Limit**  **Explanation Short** **- Term Exposure**  STEL Short - Te rm Exposure Limit A 15 - minute time - weighted average ( TWA) exposure that should not be exceeded at any

time during a workday, even if the 8 - hour TWA exposure is within the 8 - hour Threshold Limit Value ( TLV )

– TWA set by ACGIH. (OSHA may also set a STEL). Excursion Limit2 Excursion Limit Where a compound does not have a TLV - short - term exposure limit, an excursion limit may be applied. Excursions in worker exposure levels may exceed 3 times the TLV - TWA for no more than a total of 30 minutes during a workday, and under no circumstances shoul d they exceed 5 times the TLV TWA, provided that the TLV - TWA is not exceeded according to ACGIH. **Long -**  **Term Exposure** AEL Acceptable Exposure Limit This is a recommended workplace exposure limit, ty pically an 8 - hour TWA exposure limit. Manufacturers may recommend an AEL for their products, particularly where there is not an industry recommendation such as a TLV or Workplace Environmental Exposure Limit ( WEEL) or where there is no permissible exposure limit (PEL) from OSHA. PEL Permissible Exposure Limit This is a mandatory 8 - hour time - weighted average exposure limit set by OSHA. REL Recommended Exposure

Li mit This is a recommended 10 - hour TWA exposure limit set by NIOSH. TLV - TWA Threshold Limit Value

–

Ti me - Weighted Average The TWA concentration for a conventional 8 - hour workday and a 40 - hour workweek, to which it is believed that nearly all workers may

be repeatedly exposed, day

after day, fo r a working lifetime without adverse effect according to ACGIH. WEEL Workplace Environmental

Exposure Limit The TWA concentration for a conventional 8 - hour workday and a 40 - hour workweek, to which it is believed that nearly all workers may

be repeatedly exposed, day

after day, for a working lifetime without adverse effect according to AIHA.

1 All information in this table taken from EPA (1994) except where otherwis e noted. 2 AC GIH (2004)

### 3 **Table 2. 8 -** **Hour Workplace Exposure Limits and End -**  **Uses for Substitute Flow Blowing Agents Substitute**  **Exposure Limit Information**  **Listing for Substitute, by End -**  **Use** 8 -hr TWA Workplace Exposure Limit in parts per million (ppm) Abbreviation

for Type of Limit Rigid

Polyurethane (PU) & Polyiso cyanurate Laminated Boardstock Rigid PU,

Appliance **1** Rigid PU,

Spray **1** Rigid PU,

Commercial Ref & Sandwich Panels **1** Rigid PU,

Slabstock **1** Polystyrene,

Extruded Boardstock & Billet (XPS) Phenolic

Insulation Board & Bunstock Integral

Skin PU **1, 2** Polystyrene

Extruded Sheet Flexible

PU Polyolefin**3**

Water N/A N/A           

CO 2 5000 PEL            HFC - 134a 1000 WEEL X X X X X X X X X X X HFC - 152a 1000 WEEL            HFC - 245fa 200 WEEL X X  X X X X X X X X HFC - 365mfc 1000 Manufacturer ( Mfr) AE L X X X X X X X X X X Commercial blends of 7 - 13% HF C 227ea and remainder HFC 365mfc 1000 Mfr AEL  X

HFO - 1234ze 800 WEEL          Exxsol Blowing Agents 6 00 TLV           Saturated Light Hydrocarbons C3 - C6 (e.g., n -pentane) 600 to 1000 TLV          

Formic Acid 5 PEL     Acetone 250/500 REL/TLV   Methyl Formate 100 PEL      2 - Chloropropane 350 EPA AEL  

### 4 **Table 2. 8 -** **Hour Workplace Exposure Limits and End -**  **Uses for Substitute Flow Blowing Agents Substitute**  **Exposure Limit Information**  **Listing for Substitute, by End -**  **Use** 8 -hr TWA Workplace Exposure Limit in parts per million (ppm) Abbreviation

for Type of Limit Rigid

Polyurethane (PU) & Polyiso cyanurate Laminated Boardstock Rigid PU,

Appliance **1** Rigid PU,

Spray **1** Rigid PU,

Commercial Ref & Sandwich Panels **1** Rigid PU,

Slabstock **1** Polystyrene,

Extruded Boardstock & Billet (XPS) Phenolic

Insulation Board & Bunstock Integral

Skin PU **1, 2** Polystyrene

Extruded Sheet Flexible

PU Polyolefin**3**

Vacuum Panels N/A N/A  Blends of HFC 365mfc and at least 5% HFC 245fa 200 to 1000 Mfr AEL 

Ecomate 100 PEL           Formacel B 1000 Mfr AEL X Formacel TI 1000 Mfr AEL X X X X X X X Formacel Z - 6 1000 Mfr AEL X X X X X X X HFC 152a/Saturated Light Hydrocarbon Blends 600 to 1000 WEEL/TLV  Trans - 1 - chloro 3,3,3 - trifluoro prop - 1 - ene (Solstice TM LBA) 800 WEEL      

1. - Acceptability listings include blends of acceptable substitutes in these end - uses. 2. - Under the Section 610 Non - Essential Use Ban, the sale and distribution or offer for sale and distribution of polyolefin fo am manufactured with HCFCs is banned except for closed cell rigid polyethylene foam when such foam is suitable in shape, thic kness and design to be used as a product that provides insulation around pipes used in heating, plumbing, refrigeration, or industr ial process systems 

### KEY: Currently Acceptable Proposed unacceptable Currently no listing 



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### References ACGIH 2004. The Documentation of the Threshold Limit Values and Biological Exposure Indices. American Conference of Governmental Industrial Hygienists. Available online at: www.acgih.org. EPA 1994. Significant New Alternatives Policy Technical Background Document: Risk Screen on the Use of Substitutes for Class I Ozone - depleting Substances: Refrigeration and Air Conditioning. Stratospheric Protection Division. March, 1994.