April 25, 2025

AQS Reference Table

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Downoad a csv version: qualifiers.csv

This table has a "Still Active" column. If this code can be used to submit new data, this is set to YES. If this code is no longer allowed on new data, but the code may be attached to older data, it is set to NO.

Qualifier Code	Qualifier Description	Qualifier Type	Qaulifier Type Code	Still Active	Legacy Code
RA	African Dust.	Request Exclusion	REQEXC	YES
RB	Asian Dust.	Request Exclusion	REQEXC	YES
RC	Chemical Spills & Industrial Accidents.	Request Exclusion	REQEXC	YES
RD	Cleanup After a Major Disaster.	Request Exclusion	REQEXC	YES
RE	Demolition.	Request Exclusion	REQEXC	YES
RF	Fire - Canadian.	Request Exclusion	REQEXC	YES
RG	Fire - Mexico/Central America.	Request Exclusion	REQEXC	YES
RH	Fireworks.	Request Exclusion	REQEXC	YES
RI	High Pollen Count.	Request Exclusion	REQEXC	YES
RJ	High Winds.	Request Exclusion	REQEXC	YES
RK	Infrequent Large Gatherings.	Request Exclusion	REQEXC	YES
RL	Other.	Request Exclusion	REQEXC	YES
RM	Prescribed Fire.	Request Exclusion	REQEXC	YES
RN	Seismic Activity.	Request Exclusion	REQEXC	YES
RO	Stratospheric Ozone Intrusion.	Request Exclusion	REQEXC	YES
RP	Structural Fire.	Request Exclusion	REQEXC	YES
RQ	Terrorist Act.	Request Exclusion	REQEXC	YES
RR	Unique Traffic Disruption.	Request Exclusion	REQEXC	YES
RS	Volcanic Eruptions.	Request Exclusion	REQEXC	YES
RT	Wildfire-U. S.	Request Exclusion	REQEXC	YES
1	Deviation from a CFR/Critical Criteria Requirement.	Quality Assurance Qualifier	QA	YES
1V	Data reviewed and validated.	Quality Assurance Qualifier	QA	YES
2	Operational Deviation.	Quality Assurance Qualifier	QA	YES
3	Field Issue.	Quality Assurance Qualifier	QA	YES
4	Lab Issue.	Quality Assurance Qualifier	QA	YES
5	Outlier.	Quality Assurance Qualifier	QA	YES
6	QAPP Issue.	Quality Assurance Qualifier	QA	YES
7	Below Lowest Calibration Level.	Quality Assurance Qualifier	QA	YES
9	Negative value detected - zero reported.	Quality Assurance Qualifier	QA	YES
CB	Values have been Blank Corrected.	Quality Assurance Qualifier	QA	YES
CC	Clean Canister Residue.	Quality Assurance Qualifier	QA	YES
CF	Canister Bias: NATTS/UATMP Data for compounds that have failed certification for the canister.	Quality Assurance Qualifier	QA	YES
CL	Surrogate Recoveries Outside Control Limits.	Quality Assurance Qualifier	QA	YES
DI	Sample was diluted for analysis.	Quality Assurance Qualifier	QA	YES
DN	DNPH peak less than NATTS TAD requirement, reported value should be considered an estimate.	Quality Assurance Qualifier	QA	YES
EH	Estimated; Exceeds Upper Range.	Quality Assurance Qualifier	QA	YES
FB	Field Blank Value Above Acceptable Limit.	Quality Assurance Qualifier	QA	YES
FX	Filter Integrity Issue.	Quality Assurance Qualifier	QA	YES
HT	Sample pick-up hold time exceeded.	Quality Assurance Qualifier	QA	YES
LB	Lab blank value above acceptable limit.	Quality Assurance Qualifier	QA	YES
LJ	Identification Of Analyte Is Acceptable; Reported Value Is An Estimate.	Quality Assurance Qualifier	QA	YES
LK	Analyte Identified; Reported Value May Be Biased High.	Quality Assurance Qualifier	QA	YES
LL	Analyte Identified; Reported Value May Be Biased Low.	Quality Assurance Qualifier	QA	YES
MD	Value less than MDL.	Quality Assurance Qualifier	QA	YES
MS	Value reported is 1/2 MDL substituted.	Quality Assurance Qualifier	QA	YES
MX	Matrix Effect.	Quality Assurance Qualifier	QA	YES
ND	No Value Detected, Zero Reported.	Quality Assurance Qualifier	QA	YES
NS	Influenced by nearby source.	Quality Assurance Qualifier	QA	YES
QP	Pressure Sensor Questionable.	Quality Assurance Qualifier	QA	YES
QT	Temperature Sensor Questionable.	Quality Assurance Qualifier	QA	YES
QX	Does not meet QC criteria.	Quality Assurance Qualifier	QA	YES
SB	Sampler Bias: NATTS/UATMP Data for compounds that have failed certification for the sampler.	Quality Assurance Qualifier	QA	YES
SP	NATTS/UATMP data with Spike Recovery outside acceptance limits.	Quality Assurance Qualifier	QA	YES
SQ	Values Between SQL and MDL.	Quality Assurance Qualifier	QA	YES
SS	Value substituted from secondary monitor.	Quality Assurance Qualifier	QA	YES
SX	Does Not Meet Siting Criteria.	Quality Assurance Qualifier	QA	YES
TB	Trip Blank Value Above Acceptable Limit.	Quality Assurance Qualifier	QA	YES
TT	Transport Temperaure is Out of Specs.	Quality Assurance Qualifier	QA	YES
V	Validated Value.	Quality Assurance Qualifier	QA	YES
VB	Value below normal; no reason to invalidate.	Quality Assurance Qualifier	QA	YES
W	Flow Rate Average out of Spec.	Quality Assurance Qualifier	QA	YES
X	Filter Temperature Difference or Average out of Spec.	Quality Assurance Qualifier	QA	YES
XC	Canister certification expired	Quality Assurance Qualifier	QA	YES
XS	Traceable to a Standard Reference Photometer (SRP) with the Hearn (1961) 308.32 atm-1 cm-1 Ozone Cross-Section Value.	Quality Assurance Qualifier	QA	YES
Y	Elapsed Sample Time out of Spec.	Quality Assurance Qualifier	QA	YES
AA	Sample Pressure out of Limits.	Null Data Qualifier	NULL	YES	9967
AB	Technician Unavaliable.	Null Data Qualifier	NULL	YES	9968
AC	Construction/Repairs in Area.	Null Data Qualifier	NULL	YES	9969
AD	Shelter Storm Damage.	Null Data Qualifier	NULL	YES	9970
AE	Shelter Temperature Outside Limits.	Null Data Qualifier	NULL	YES	9971
AF	Scheduled but not Collected.	Null Data Qualifier	NULL	YES	9972
AG	Sample Time out of Limits.	Null Data Qualifier	NULL	YES	9973
AH	Sample Flow Rate or CV out of Limits.	Null Data Qualifier	NULL	YES	9974
AI	Insufficient Data (cannot calculate).	Null Data Qualifier	NULL	YES	9975
AJ	Filter Damage.	Null Data Qualifier	NULL	YES	9976
AK	Filter Leak.	Null Data Qualifier	NULL	YES	9977
AL	Voided by Operator.	Null Data Qualifier	NULL	YES	9978
AM	Miscellaneous Void.	Null Data Qualifier	NULL	YES	9979
AN	Machine Malfunction.	Null Data Qualifier	NULL	YES	9980
AO	Bad Weather.	Null Data Qualifier	NULL	YES	9981
AP	Vandalism.	Null Data Qualifier	NULL	YES	9982
AQ	Collection Error.	Null Data Qualifier	NULL	YES	9983
AR	Lab Error.	Null Data Qualifier	NULL	YES	9984
AS	Poor Quality Assurance Results.	Null Data Qualifier	NULL	YES	9985
AT	Calibration.	Null Data Qualifier	NULL	YES	9986
AU	Monitoring Waived.	Null Data Qualifier	NULL	YES	9987
AV	Power Failure.	Null Data Qualifier	NULL	YES	9988
AW	Wildlife Damage.	Null Data Qualifier	NULL	YES	9989
AX	Precision Check.	Null Data Qualifier	NULL	YES	9990
AY	Q C Control Points (zero/span).	Null Data Qualifier	NULL	YES	9991
AZ	Q C Audit.	Null Data Qualifier	NULL	YES	9992
BA	Maintenance/Routine Repairs.	Null Data Qualifier	NULL	YES	9993
BB	Unable to Reach Site.	Null Data Qualifier	NULL	YES	9994
BC	Multi-point Calibration.	Null Data Qualifier	NULL	YES	9995
BD	Auto Calibration.	Null Data Qualifier	NULL	YES	9996
BE	Building/Site Repair.	Null Data Qualifier	NULL	YES	9997
BF	Precision/Zero/Span.	Null Data Qualifier	NULL	YES	9998
BG	Missing ozone data not likely to exceed level of standard.	Null Data Qualifier	NULL	YES	9966
BH	Interference/co-elution/misidentification.	Null Data Qualifier	NULL	YES	9965
BI	Lost or damaged in transit.	Null Data Qualifier	NULL	YES	9964
BJ	Operator Error.	Null Data Qualifier	NULL	YES	9963
BK	Site computer/data logger down.	Null Data Qualifier	NULL	YES	9962
BL	QA Audit.	Null Data Qualifier	NULL	YES	9961
BM	Accuracy check.	Null Data Qualifier	NULL	YES	9960
BN	Sample Value Exceeds Media Limit.	Null Data Qualifier	NULL	YES	9947
BR	Sample Value Below Acceptable Range.	Null Data Qualifier	NULL	YES
CS	Laboratory Calibration Standard.	Null Data Qualifier	NULL	YES	9953
DA	Aberrant Data (Corrupt Files, Aberrant Chromatography, Spikes, Shifts).	Null Data Qualifier	NULL	YES	9951
DL	Detection Limit Analyses.	Null Data Qualifier	NULL	YES	9949
EC	Exceeds Critical Criteria.	Null Data Qualifier	NULL	YES
FI	Filter Inspection Flag.	Null Data Qualifier	NULL	YES	9959
MB	Method Blank (Analytical).	Null Data Qualifier	NULL	YES	9955
MC	Module End Cap Missing.	Null Data Qualifier	NULL	YES	9958
QV	Quality Control Multi-point Verification.	Null Data Qualifier	NULL	YES
SA	Storm Approaching.	Null Data Qualifier	NULL	YES	9957
SC	Sampler Contamination.	Null Data Qualifier	NULL	YES	9948
ST	Calibration Verification Standard.	Null Data Qualifier	NULL	YES	9954
SV	Sample Volume out of limits.	Null Data Qualifier	NULL	YES
TC	Component Check & Retention Time Standard.	Null Data Qualifier	NULL	YES	9952
TS	Holding Time Or Transport Temperature Is Out Of Specs.	Null Data Qualifier	NULL	YES	9956
XX	Experimental Data.	Null Data Qualifier	NULL	YES	9950
1C	A 1-Point QC check exceeds acceptance criteria but there is compelling evidence that the analyzer data is valid.	Missing QA/QC Audit	NULL QC	YES
1F	No 1 Point QC but need to count for completeness	Missing QA/QC Audit	NULL QC	YES
IA	African Dust.	Informational Only	INFORM	YES
IB	Asian Dust.	Informational Only	INFORM	YES
IC	Chem. Spills & Indust Accidents.	Informational Only	INFORM	YES
ID	Cleanup After a Major Disaster.	Informational Only	INFORM	YES
IE	Demolition.	Informational Only	INFORM	YES
IF	Fire - Canadian.	Informational Only	INFORM	YES
IG	Fire - Mexico/Central America.	Informational Only	INFORM	YES
IH	Fireworks.	Informational Only	INFORM	YES
II	High Pollen Count.	Informational Only	INFORM	YES
IJ	High Winds.	Informational Only	INFORM	YES
IK	Infrequent Large Gatherings.	Informational Only	INFORM	YES
IL	Other.	Informational Only	INFORM	YES
IM	Prescribed Fire.	Informational Only	INFORM	YES
IN	Seismic Activity.	Informational Only	INFORM	YES
IO	Stratospheric Ozone Intrusion.	Informational Only	INFORM	YES
IP	Structural Fire.	Informational Only	INFORM	YES
IQ	Terrorist Act.	Informational Only	INFORM	YES
IR	Unique Traffic Disruption.	Informational Only	INFORM	YES
IS	Volcanic Eruptions.	Informational Only	INFORM	YES
IT	Wildfire-U. S.	Informational Only	INFORM	YES
J	Construction.	Informational Only	INFORM	YES
E	Forest Fire.	Request Exclusion	REQEXC	NO
RU	Wildland Fire Use Fire-U. S.	Request Exclusion	REQEXC	NO
8	QA/QC Unknown.	Quality Assurance Qualifier	QA	NO
PQ	Values Between PQL And MDL.	Quality Assurance Qualifier	QA	NO
T	Multiple PM2.5 Validity Flags.	Quality Assurance Qualifier	QA	NO
A	High Winds.	Informational Only	INFORM	NO
B	Stratospheric Ozone Intrusion.	Informational Only	INFORM	NO
C	Volcanic Eruption.	Informational Only	INFORM	NO
D	Sandblasting.	Informational Only	INFORM	NO
F	Structural Fire.	Informational Only	INFORM	NO
G	High Pollen Count.	Informational Only	INFORM	NO
H	Chem. Spills & Indust. Accidents.	Informational Only	INFORM	NO
I	Unusual Traffic Congestion.	Informational Only	INFORM	NO
IU	Wildland Fire Use Fire-U. S.	Informational Only	INFORM	NO
K	Agricultural Tilling.	Informational Only	INFORM	NO
L	Highway Construction.	Informational Only	INFORM	NO
M	Rerouting of Traffic.	Informational Only	INFORM	NO
N	Sanding/Salting of Streets.	Informational Only	INFORM	NO
O	Infrequent Large Gatherings.	Informational Only	INFORM	NO
P	Roofing Operations.	Informational Only	INFORM	NO
Q	Prescribed Burning.	Informational Only	INFORM	NO
R	Cleanup After a Major Disaster.	Informational Only	INFORM	NO
S	Seismic Activity.	Informational Only	INFORM	NO
U	Sahara Dust.	Informational Only	INFORM	NO
Z	Other event.	Informational Only	INFORM	NO