1 BY A JUDGMENT OF 12 DECEMBER 1978 , WHICH WAS RECEIVED AT THE COURT REGISTRY ON 22 JANUARY 1979 , THE TARIEFCOMMISSIE REFERRED TO THE COURT FOR A PRELIMINARY RULING UNDER ARTICLE 177 OF THE EEC TREATY THREE QUESTIONS CONCERNING THE INTERPRETATION OF HEADING 84.12 OF THE COMMON CUSTOMS TARIFF .
2 ACCORDING TO THE JUDGMENT MAKING THE REFERENCE THESE QUESTIONS AROSE IN THE COURSE OF AN ACTION BETWEEN THE CLETON UNDERTAKING - THE PLAINTIFF IN THE MAIN ACTION - AND THE CUSTOMS AUTHORITIES OF THE NETHERLANDS CONCERNING THE TARIFF CLASSIFICATION OF MACHINES CALLED ' ' THERMO-KING TRANSPORT REFRIGERATION UNITS ' ' , IMPORTED FROM A NON-MEMBER COUNTRY . THESE MACHINES , OF WHICH THERE ARE ABOUT 20 TYPES , DIFFERING ACCORDING TO THEIR CAPACITY AND MOTOR POWER , WERE IMPORTED , AND ARE USED MOSTLY FOR COOLING OR HEATING THE LOAD COMPARTMENTS IN LORRIES , CONTAINERS AND OTHER MEANS OF TRANSPORT ; ONLY TWO TYPES ( XKW 10 AND 20 ) CAN BE USED FOR COOLING ALONE .
3 THE PLAINTIFF IN THE MAIN ACTION DECLARED THE MACHINES UNDER SUBHEADING B OF TARIFF HEADING 84.15 WHICH READS AS FOLLOWS : ' ' REFRIGERATORS AND REFRIGERATING EQUIPMENT ( ELECTRICAL AND OTHER ): A . EVAPORATORS AND CONDENSERS , EXCLUDING THOSE FOR DOMESTIC REFRIGERATORS ; B . OTHER . . . ' ' , AND GIVES RISE TO A CONVENTIONAL RATE OF DUTY OF 5% . THE COMPETENT INSPECTOR AMENDED THE DECLARATION , HOWEVER , AND CLASSIFIED THE MACHINES UNDER HEADING 84.12 : ' ' AIR-CONDITIONING MACHINES , SELF-CONTAINED , COMPRISING A MOTOR-DRIVEN FAN AND ELEMENTS FOR CHANGING THE TEMPERATURE AND HUMIDITY OF AIR ' ' . THIS HEADING GIVES RISE TO A CONVENTIONAL RATE OF DUTY OF 8% .
4 THE PLAINTIFF IN THE MAIN ACTION DISPUTED THIS CLASSIFICATION , CLAIMING THAT THE MACHINES WERE DESIGNED PURELY TO REGULATE THE TEMPERATURE INSIDE THE COMPARTMENTS AND NOT THE DEGREE OF HUMIDITY OF THE AIR . IT IS TRUE , IT ADDS , THAT OWING TO THE LAWS OF PHYSICS ANY CHANGE IN TEMPERATURE IN THE SURROUNDING ATMOSPHERE ALTERS THE DEGREE OF HUMIDITY OF THE AIR , BUT SO FAR AS THE MACHINES IN QUESTION ARE CONCERNED THIS IS AN UNSOUGHT EFFECT , WHICH IS EVEN CONSIDERED UNDESIRABLE , AND WHICH THE MACHINES IN QUESTION ARE NOT CAPABLE OF REGULATING .
5 IN ORDER TO SETTLE THE DISPUTE THE NATIONAL COURT HAS REFERRED THREE QUESTIONS TO THE COURT . IN THE FIRST QUESTION IT ASKS : ' ' 1 . SHOULD HEADING 84.12 OF THE TARIFF BE INTERPRETED AS MEANING THAT THE WORDS ' AIR-CONDITIONING ' IN CONJUNCTION WITH THE WORDS ' CHANGING THE TEMPERATURE AND HUMIDITY OF AIR ' ALSO INCLUDE THE MAINTENANCE BY MECHANICAL OR OTHER MEANS OF A PRE-SELECTED TEMPERATURE , COUPLED WITH A CHANGE IN THE HUMIDITY WHICH IS NOT INTENDED AND CANNOT BE REGULATED? ' ' IF THE ANSWER TO THE FIRST QUESTION IS IN THE AFFIRMATIVE , THE TARIEFCOMMISSIE ASKS : ' ' 2 . SHOULD HEADING 84.12 OF THE TARIFF BE INTERPRETED AS MEANING THAT THE WORDS ' AIR-CONDITIONING ' SHOULD BE UNDERSTOOD TO INCLUDE THE MAINTENANCE BY MECHANICAL OR OTHER MEANS OF ONLY A PRE-SELECTED LOWERING OF THE TEMPERATURE , COUPLED WITH A CHANGE IN THE HUMIDITY WHICH IS NOT INTENDED AND CANNOT BE REGULATED? ' ' THE THIRD QUESTION , TO BE ANSWERED IF THE REPLY TO THE FIRST QUESTION IS IN THE NEGATIVE , IS : ' ' 3 . WHAT IS THEN TO BE UNDERSTOOD UNDER THE TERM ' HUMIDITY ' USED IN HEADING 84.12? IS THE TERM TO BE UNDERSTOOD AS MEANING RELATIVE HUMIDITY OR ABSOLUTE HUMIDITY? ' '
6 THE NETHERLANDS CUSTOMS AUTHORITIES ARGUE THAT THE QUESTION WHETHER THE MACHINES IN QUESTION ARE SPECIALLY DESIGNED TO HAVE THIS HUMIDIFYING OR DE-HUMIDIFYING EFFECT OR , ON THE CONTRARY , THIS IS MERELY A RESULT OF CHANGES IN TEMPERATURE , HAS NO BEARING ON THEIR CLASSIFICATION . IN BOTH CASES , THE RELEVANT TARIFF HEADING IS HEADING 84.12 . THEY BASE THIS VIEW ON THE WORDING OF BOTH THE EXPLANATORY NOTES OF THE CUSTOMS CO-OPERATION COUNCIL RELATING TO HEADING 84.12 ( 1975 VERSION ) AND THE EXPLANATORY NOTES TO THE COMMON CUSTOMS TARIFF OF THE EUROPEAN COMMUNITIES RELATING TO THAT HEADING AND PUBLISHED IN THE 12TH AMENDING SUPPLEMENT ( 1 JULY 1978 ) TO THOSE NOTES . THE COMPETENT INSPECTOR ALSO DREW THE ATTENTION OF THE NATIONAL COURT TO THE WORDING OF THE MINUTES OF A MEETING OF THE TARIFF COMMISSION OF THE BENELUX ECONOMIC UNION OF 20 AND 21 DECEMBER 1966 ACCORDING TO WHICH THE MACHINES IN QUESTION SHOULD BE CLASSIFIED UNDER HEADING 84.12 , BUT IT IS NOW AGREED THAT THIS IS NOT DECISIVE ALTHOUGH IT DOES GIVE AN INDICATION OF THE PRACTICE WHICH HAS BEEN FOLLOWED BY THE CUSTOMS AUTHORITIES SINCE 1966 .
7 THE COMMISSION TAKES THE SAME VIEW AS THE NETHERLANDS AUTHORITIES AS REGARDS THE CONCLUSIONS TO BE DRAWN FROM THE EXPLANATORY NOTES OF THE CUSTOMS CO-OPERATION COUNCIL AND THOSE OF THE COMMON CUSTOMS TARIFF OF THE EUROPEAN COMMUNITIES . IT ALSO EMPHASIZES THE NECESSITY OF ESTABLISHING SIMPLE OBJECTIVE CRITERIA FOR DISTINGUISHING BETWEEN ONE CUSTOMS HEADING AND ANOTHER . THIS REQUIREMENT MEANS THAT SUBJECTIVE CRITERIA SUCH AS WHETHER A MACHINE WAS DESIGNED TO PRODUCE A PARTICULAR EFFECT OR NOT , MUST BE AVOIDED IN FAVOUR OF OBJECTIVE CRITERIA WHICH ARE READILY VERIFIABLE , SUCH AS THE FACT THAT A GIVEN EFFECT IS IN FACT PRODUCED BY A MACHINE , WHETHER OR NOT IT IS INTENDED . FIRST QUESTION
8 ACCORDING TO THE WORDING OF HEADING 84.12 ITSELF , IT COVERS ONLY MACHINES ' ' FOR CHANGING THE TEMPERATURE AND HUMIDITY ' ' ( VOOR HET WIJZIGEN VAN TEMPERATUUR EN VOCHTIGHEID ). THIS WORDING EXCLUDES FROM THE AMBIT OF THIS HEADING AN APPARATUS WHICH IS ONLY DESIGNED TO REGULATE TEMPERATURE , IF THE ALTERATION IN THE DEGREE OF HUMIDITY OF THE AIR IN THE SURROUNDING ATMOSPHERE IS MERELY THE RESULT OF TEMPERATURE CHANGES IN THAT ATMOSPHERE WHICH IS AUTOMATIC , UNSOUGHT , AND WHICH CANNOT BE REGULATED . BY USING THE WORDS ' ' FOR CHANGING THE TEMPERATURE AND HUMIDITY ' ' THE CUSTOMS HEADING ENVISAGES MACHINES PERMITTING THE SELECTION OF , ON THE ONE HAND , A GIVEN AND SUITABLE TEMPERATURE AND , ON THE OTHER HAND , A GIVEN AND SUITABLE DEGREE OF HUMIDITY WHICH IS NOT SOLELY THE RESULT OF THE TEMPERATURE WHICH HAS BEEN OBTAINED .
9 THIS INTERPRETATION IS CONFIRMED BY THE EXPLANATORY NOTES DRAWN UP BY THE CUSTOMS CO-OPERATION COUNCIL WHICH , AS THE COURT HAS CONFIRMED ON A NUMBER OF OCCASIONS , ARE , IN THE ABSENCE OF SPECIFIC PROVISIONS OF COMMUNITY LAW , AN AUTHORITATIVE SOURCE FOR INTERPRETING THE HEADINGS TO THE COMMON CUSTOMS TARIFF . ACCORDING TO THOSE NOTES , HEADING 84.12 ' ' COVERS CERTAIN APPARATUS FOR MAINTAINING REQUIRED CONDITIONS OF TEMPERATURE AND HUMIDITY IN ENCLOSED SPACES . . . ' ' . IT EXPLAINS FURTHER THAT THE HEADING APPLIES ONLY TO MACHINES WHICH ARE ' ' ( 1 ) . . . ( 2 ) DESIGNED TO CHANGE BOTH THE TEMPERATURE ( A HEATING OR COOLING ELEMENT OR BOTH ) AND THE HUMIDITY ( A HUMIDIFYING OR DRYING ELEMENT OR BOTH ) OF AIR , AND ( 3 ) . . . ' ' . IT ALSO STATES THAT THE HEADING EXCLUDES ' ' APPARATUS WHICH , ALTHOUGH SELF-CONTAINED AND INCORPORATING A MOTOR-DRIVEN FAN , HAS THE SOLE FUNCTION OF CHANGING EITHER TEMPERATURE OR HUMIDITY OF THE AIR . . . ' ' .
10 IT IS TRUE THAT IT IS STATED IN THE SAME EXPLANATORY NOTE THAT THE ELEMENTS FOR HUMIDIFYING OR DRYING THE AIR MAY OR MAY NOT , ACCORDING TO THE CIRCUMSTANCES , BE SEPARATE FROM THOSE FOR HEATING OR COOLING IT . ' ' CERTAIN TYPES INCORPORATE ONLY A SINGLE UNIT WHICH CHANGES BOTH THE TEMPERATURE AND , BY CONDENSATION , THE HUMIDITY OF THE AIR . THESE AIR-CONDITIONING MACHINES COOL AND DRY ( BY CONDENSATION OF WATER VAPOUR ON A COLD COIL ) THE AIR OF THE ROOM IN WHICH THEY ARE INSTALLED . . . ' ' . THIS EXPLANATION NEED NOT , HOWEVER , ALTER THE INTERPRETATION SET OUT ABOVE , FOR THE WORDING REVEALS THAT EVEN IF THE UNIT IN QUESTION IS THE ONLY ONE , IT MUST IN EVERY CASE INCLUDE A SPECIAL ELEMENT , FOR EXAMPLE A COLD COIL , WHICH IS INTENDED IN PARTICULAR TO CONDENSE THE WATER VAPOUR .
11 THE COMMISSION ALSO REFERS TO ' ' THE EXPLANATORY NOTES TO THE CUSTOMS TARIFF OF THE EUROPEAN COMMUNITIES ' ' RELATING TO HEADING 84.12 , WHICH WERE DRAWN UP IN 1977 AND READ AS FOLLOWS : ' ' AIR-CONDITIONING MACHINES , SELF-CONTAINED , COMPRISING A MOTOR-DRIVEN FAN AND ELEMENTS FOR CHANGING THE TEMPERATURE AND HUMIDITY OF AIR . AIR-CONDITIONING MACHINES WHICH ARE NOT EQUIPPED WITH A DEVICE FOR SELECTING THE DEGREE OF HUMIDITY OF AIR ARE INCLUDED IN THIS HEADING , PROVIDED THAT THE MACHINES COMPLY WITH THE CRITERIA IN THE EXPLANATORY NOTES TO THE CCC NOMENCLATURE , HEADING NO 84.12 . THIS HEADING THEREFORE COVERS ' ' COOLING/HEATING UNITS FOR TRAILERS ' ' WHICH COOL OR HEAT THE LOAD COMPARTMENTS OF LORRIES AS WELL AS CHANGE THE HUMIDITY OF THE AIR BY CONDENSATION ' ' .
12 SINCE , AS THE COURT HAS STATED , THE EXPLANATORY NOTES DRAWN UP BY THE CUSTOMS CO-OPERATION COUNCIL ARE AN AUTHENTIC SOURCE FOR INTERPRETATION ONLY IN THE ABSENCE OF SPECIFIC PROVISIONS OF COMMUNITY LAW , THE QUESTION MIGHT ARISE WHETHER - SUBJECT TO THE OBSERVATION THAT THEY , TOO , ARE MERELY AN INTERPRETATIVE INSTRUMENT OF AN ADMINISTRATIVE NATURE - THE EUROPEAN COMMUNITIES ' NOTES ON THE COMMON CUSTOMS TARIFF SHOULD NOT BE PREFERRED TO THOSE OF THE CUSTOMS CO-OPERATION COUNCIL .
13 HOWEVER , THIS QUESTION DOES NOT NEED TO BE ANSWERED IN ORDER TO GIVE A REPLY TO THE NATIONAL COURT . IT IS EXPRESSLY STATED IN THE NOTICE WHICH PRECEDES THE EXPLANATORY NOTES TO THE CUSTOMS TARIFF OF THE EUROPEAN COMMUNITIES THAT THEY ARE NOT INTENDED TO REPLACE THE EXPLANATORY NOTES OF THE CUSTOMS CO-OPERATION COUNCIL BUT ONLY TO SUPPLEMENT THEM . CONSEQUENTLY , THE NOTE IN QUESTION MUST BE INTERPRETED IN THE LIGHT OF THE ONE WHICH HAS BEEN COMMENTED ON ABOVE . IT FOLLOWS FROM BOTH NOTES THAT A SINGLE DEVICE WHICH SERVES TO REGULATE BOTH THE TEMPERATURE AND THE DEGREE OF HUMIDITY COMES UNDER HEADING 84.12 PROVIDED THAT IT DOES ENABLE THEM BOTH TO BE REGULATED . FOR HEADING 84.12 TO APPLY IT IS NOT NECESSARY TO HAVE A SPECIAL DEVICE FOR REGULATING THE DEGREE OF HUMIDITY OF THE AIR PROVIDED THAT THE SINGLE DEVICE INCLUDES AN ELEMENT WHICH AT LEAST MAKES IT POSSIBLE , IF NECESSARY , TO ADJUST THE DEGREE OF HUMIDITY WHICH RESULTS AUTOMATICALLY FROM THE TEMPERATURE SOUGHT AND OBTAINED .
14 THE FOREGOING OBSERVATIONS ALSO SHOW THAT THE ARGUMENT PUT FORWARD BY THE COMMISSION BASED ON THE NEED TO CLASSIFY GOODS UNDER THE COMMON CUSTOMS TARIFF ON THE BASIS OF THEIR OBJECTIVE CHARACTERISTICS , IN THE INTERESTS OF LEGAL CERTAINTY AND ADMINISTRATIVE CONVENIENCE , MUST BE REJECTED . THAT PRINCIPLE OF INTERPRETATION , THE IMPORTANCE OF WHICH HAS BEEN ACKNOWLEDGED BY THE COURT , IS NOT CALLED IN QUESTION BY THE INTERPRETATION WHICH HAS BEEN ADOPTED BECAUSE THE LATTER IMPLIES THAT IN ORDER TO FALL WITHIN THE SPHERE OF HEADING 84.12 - EVEN IF THE APPARATUS DOES NOT HAVE SEPARATE DEVICES FOR REGULATING TEMPERATURE AND HUMIDITY - IT MUST AT LEAST HAVE AN ELEMENT MAKING IT POSSIBLE TO ADJUST THE DEGREE OF HUMIDITY OF THE AIR , RESULTING AUTOMATICALLY FROM THE TEMPERATURE WHICH THE APPARATUS IS INTENDED TO ESTABLISH .
15 ESTABLISHING THE EXISTENCE OF SUCH ELEMENTS INVOLVES THE APPLICATION BY THE RELEVANT AUTHORITIES OF OBJECTIVE , NOT SUBJECTIVE , JUDGMENT AND PRESENTS NO MORE DIFFICULTY THAN THAT INVOLVED IN ESTABLISHING THE EXISTENCE OF THE OTHER ELEMENTS DESCRIBED IN THE NOTES CONCERNING HEADING 84.12 .
16 THE REPLY TO THE FIRST QUESTION SHOULD THEREFORE BE THAT HEADING 84.12 OF THE COMMON CUSTOMS TARIFF APPLIES ONLY TO MACHINES WHICH INCLUDE ELEMENTS DESIGNED BOTH TO ALTER THE SURROUNDING TEMPERATURE IN A GIVEN SPACE AND TO REGULATE THE DEGREE OF HUMIDITY OF THE AIR IN THAT SPACE , OR WHICH ARE AT LEAST INTENDED AND MAKE IT POSSIBLE TO ADJUST THE LEVEL OF HUMIDITY WHICH IS MERELY THE AUTOMATIC RESULT OF THE TEMPERATURE SELECTED . IT DOES NOT APPLY TO MACHINES MADE SOLELY FOR THE PURPOSE OF CHANGING THE TEMPERATURE OF THE SURROUNDING ATMOSPHERE , WHERE THE DEGREE OF HUMIDITY OF THAT ATMOSPHERE CHANGES ONLY AS AN AUTOMATIC RESULT , WHICH CAN NEITHER BE REGULATED NOR ADJUSTED , OF THE TEMPERATURE . QUESTIONS 2 AND 3
17 THE SECOND QUESTION HAS BEEN PUT BY THE NATIONAL COURT ONLY IN CASE THE FIRST QUESTION SHOULD BE ANSWERED IN THE AFFIRMATIVE . THERE IS ACCORDINGLY NO NEED TO ANSWER IT . HOWEVER , IN CASE THE FIRST QUESTION SHOULD BE ANSWERED IN THE NEGATIVE , THE COURT IS ASKED HOW THE TERM ' ' HUMIDITY ' ' IN HEADING 84.12 SHOULD BE INTERPRETED , AND IN PARTICULAR WHETHER IT IS TO BE UNDERSTOOD AS MEANING ABSOLUTE HUMIDITY OR RELATIVE HUMIDITY .
18 ACCORDING TO THE EVIDENCE SUBMITTED TO THE COURT ABSOLUTE HUMIDITY IS THE QUANTITY OF WATER VAPOUR ACTUALLY PRESENT PER UNIT OF VOLUME OF THE SURROUNDING ATMOSPHERE AT A GIVEN MOMENT , WHEREAS RELATIVE HUMIDITY IS THE RATIO BETWEEN THAT ACTUAL QUANTITY AND THE MAXIMUM QUANTITY OF WATER VAPOUR WHICH THAT ATMOSPHERE IS CAPABLE OF HOLDING , THE ABSOLUTE HUMIDITY BEING THE NUMERATOR , AND THE MAXIMUM QUANTITY THE DENOMINATOR , OF THAT FRACTION .
19 IT WOULD APPEAR FROM THIS EXPLANATION THAT THE TERM ' ' RELATIVE HUMIDITY ' ' REFERRED TO BY THE NATIONAL COURT CORRESPONDS TO THAT OF THE DEGREE OF HUMIDITY . THAT BEING SO , THE EXPRESSION ' ' FOR CHANGING THE TEMPERATURE AND HUMIDITY OF AIR ' ' IN HEADING 84.12 MEANS CHANGING THE RELATIVE HUMIDITY .