Elastomers Guide II - Sample Page

SYMBOLIC RATING	VOLUMETRIC SWELLING	LOSS OF TENSILE STRENGTH	DESCRIPTION OF ATTACK
A	< 15% in 30 days to 1 year	< 15% in 30 days to 1 year	Excellent, little or no swelling or softening or surface deterioration.
B	< 30% in 30 days to 1 year	< 30% in 30 days to 1 year	Good chemical resistance. Minor chemical attack, swelling, softening or surface deterioration.
C	< 50% in 30 days to 1 year	< 60% in 30 days to 1 year	Limited chemical resistance. Moderate chemical attack. Conditional service.
NR	> 50% immediately to 1 year	> 60% immediately to 1 year	Severe attack, swelling, softening, or dissolved within minutes to years. Not recommended.
Q	-	-	Questionable resistance. Doubtful usage.
TEST	-	-	Test before using.

A to 70°F	< 15% volume increase or < 15% loss of tensile strength at 100% concentration or concentrated or saturated solution to 70°F. Little or no chemical attack.
A to 100% to 70°F	< 15% volume increase or < 15% loss of tensile strength in any concentration from 0 to 100% at 70°F. Little or no chemical attack.
A to 20% to 70°F	< 15% volume increase or < 15% loss of tensile strength in any concentration from 0 to 20% at 70°F. Little or no chemical attack.
B 20-50% 70-140°F	< 15 to 30% volume increase or 15 to 30% loss of tensile strength, from 20% to 50% concentration of solution between 70°F and 140°F.
B to conc to 212°F	< 15 to 30% volume increase or 15 to 30% loss of tensile strength, in any concentration to 100% at any temperature from 70°F to 212°F.
AC at 70°F	0% to 30% volume increase, or 0% to 30% loss of tensile strength at 100% concentration or concentrated, or saturated solution, at 70°F. Reported data varies widely possibly due to compounding differences within the same generic family.
NR at 70°F	> 50% volume increase or > 60% loss of tensile strength at 100% concentration, or concentrated, or saturated solution at 70°F. Severe attack. Not recommended.
A/NR at 70°F	15% to > 50% volume increase or < 15% to > 60% loss of tensile strength at 100% concentration, or concentrated, or saturated solution at 70°F. Varying or variable rates reported by multiple sources. Use only after specific testing of all parameters to be encountered.

+55% vol 3 days 70°F	55% volume increase during 3 day period at 100% concentration, at 70°F.
+1 -5% vol 3 days 70°F	+1% to +5% volume increase during 3 day period at 100% concentration at 70°F.
-1 to +5% vol 3 days 70°F	1% decrease to +5% increase in volume during 3 day period at 100% concentration at 70°F.
+1.8% vol 28% conc 7 days 70°F	+1.8% volume increase at 28% concentration during 7 day period at 70°F.
-2 to -4% vol 3 days 70°F	2% to 4% decrease in volume during 4 day period at 100% concentration at 70°F.
-41% T.S. 50% conc 7 days 77°F	41% loss of tensile strength in 50% concentration solution during 7 day period at 77°F.