| Grade | Density (pcf) | Firmness (ILD) (4" thick, 25%) | Firmness (ILD) (4" thick, 65%) | 
| HR 32 | 2.6 | 32-38 | 65-86 | 
| HR 55 | 2.8 | 51-59 | 120–156 | 
| HR 70 | 3.2 | 69–79 | 165-190 | 
Flammability Standards
HR Polyfoam has been tested to meet the following flammability standards:
- California Technical Bulletin 117
- FMVSS-302 (Automotive Flammability)
- 14 CFR (FAR) 25.853(a), Vertical Burn
|   | This product meets and exceeds automotive flammability standards. | 
|   | • This product is acceptable for use in all types aircraft and rotorcraft. | 
|  | This product is acceptable for use in marine interiors, but is not water resistant or repellent. It is highly buoyant with the use of a water-blocking layer. | 
|  | Unknown at this time whether this material is acceptable for use in Railway applications. | 
 
		 
		 
		 
								
								
									 
								
								
									 
								
								
									