Advanced Industrial Measurements (AIM)
has tested U.S. Rockets motors to each of several standards:
NAR S&T
TRA TMT
NFPA-1122
NFPA-1127
AIM

AIM has approved as certified the following U.S. Rockets motors:

24mm Expendable
C12 D6 D12 D24 E12 E25 E50 E100 F25 F50 F100 F200
G35 G70 G140 G280 
H100
Delays of 2,4,8,12 seconds

24mm Reloadable
none

29mm Expendable
E10 E20 E40 F007 F20 F40 F80 F160 G008 G30 G60 G120 G240
G40 G80 G160 H60 H120 H240 H80 H160 H320 H640 I110 I150
J160
Delays of 4,8,12 seconds

29mm Reloadable (60N-s nominal ea)
60, 120, 180, 320 Standard 
60, 120, 180, 320 Fast 
60, 120, 180, 320 Whitestar 
60, 120, 180, 320 Buttkicker 
60, 120, 180, 320 Firestarter 
60, 120, 180, 320 Stardust 
Delays of 8,12 seconds

38mm Expendable
H25 H55 H110 H220 H440 I70 I220 I440 J220 J440 J880 J1760 K660
Delays of 4,8,12 seconds

38mm Reloadable (240N-s nominal ea)
240, 480, 720, 960 Standard
240, 480, 720, 960 Fast
240, 480, 720, 960 Whitestar
240, 480, 720, 960 Buttkicker
240, 480, 720, 960 Firestarter
240, 480, 720, 960 Stardust
Delays of 8,12 seconds

54mm Expendable
I40 I65 I140 I280 J125 J250 J500 K250 K500 K1000
L375 L750 L1500 L1000
Delays of 8,12, 16 seconds

54mm Reloadable (240N-s nominal ea)
240, 480, 720, 960, 1200, 2400 Standard
240, 480, 720, 960, 1200, 2400 Fast
240, 480, 720, 960, 1200, 2400 Whitestar
240, 480, 720, 960, 1200, 2400 Buttkicker
240, 480, 720, 960, 1200, 2400 Firestarter
240, 480, 720, 960, 1200, 2400 Stardust
Delays of 8,12, 16 seconds

75mm Reloadable (1280N-s nominal ea)
1280 grains (stackable to manufacturer specifications)
Standard, Fast, Whitestar, Buttkicker, Firestarter, Stardust 
Delays of 16 seconds

98mm Reloadable (2560N-s nominal ea)
2560 grains (stackable to manufacturer specifications)
Standard, Fast, Whitestar, Buttkicker, Firestarter, Stardust 
Delays of 16 seconds

152mm Reloadable  (10000N-s nominal)
10000 grains (stackable to manufacturer specifications)
Standard, Fast, Whitestar, Buttkicker, Firestarter, Stardust 
Delays of 16 seconds

Note.  All delays are consumer modifiable to shorter times
according to manufacturer specified instructions and tools.

Igniters for use with USR motors:
USR wire wrapped Thermalite or igniter cord
USR dipped SCB type
USR dipped Bridge wire type
USR pyro upper stage type
Dipped "electric matches" and wires using:
Igniterman
Firestar
Thermalite or equivelent
Visco with dip and sheath using:
Igniterman
Firestar
Copperhead
Electric matches include daveyfire and oxoral and atlas matches

Booster motors made by modifying the delay must have a mimimum 
of 1.5 seconds delay for all regressive trace and endburner motors 
(USR D USR E) and 2.0 seconds for coreburners 29mm and under and 
3.0 seconds over 29mm (USR B).

The exact same motors relabeled as other brands are also certified
on a case by case basis as approved and announced by AIM.

Effective 02 February 2000.

AIM is a private for profit scientific testing firm.