[en] This doctoral thesis addresses the study of different intercomparison exercises - the provision of proficiency tests (EA) within the framework of market control campaigns with the participation of 50 laboratories from 24 countries: Saudi Arabia, Argentina, Bangladesh, Belgium, Bosnia and Herzegovina, Bulgaria, Canada, China, Colombia, Ivory Coast, Croatia, Cuba, Spain, Italy, Lithuania, Morocco, Moldova, Pakistan, Portugal, United Kingdom, Serbia, Turkey, United States and Jordan. and participation in collaborative exercises - which were carried out at the Galician Consumer Laboratory (LCG), valuing the figure of the supplier and placing special emphasis on the exchange of information and collaboration as ways to improve the quality of the results.  Several rounds of EA were carried out for the evaluation of textile fibre identification. Optical and scanning electron microscopy, solubility tests and infrared spectroscopy were used in the preparation; methodologies described in CEN ISO/TR 11827, in whose review we participate through the CEN/TC248/WG30 group. The evaluation was carried out according to the ISO 13528 standard. 1,480 results from 47 laboratories in 21 countries and information from surveys were studied, confirming that experience and the combination of techniques are key for correct identification.  Several rounds of EA were provided for the evaluation of the quantitative determination of the composition of textile products according to the procedures described in the ISO 1833 series; methods harmonized with Regulation (EU) 1007/2011, in accordance with the mandate M/532 of the European Commission, a process in which we participate through the CEN/TC248/WG30 group. The evaluation was carried out according to the ISO 13528 standard and with the Naji-Plot graphic method. 872 results from 47 laboratories in 21 countries and information obtained from surveys were studied, detecting differences in the interpretation of technical regulations. 494 uncertainties were analysed, determining that there is a relationship between the discrepant results and an inadequate calculation of the uncertainty.  Several rounds of the EA were provided for the evaluation of the qualitative determination of colour fastness using the ISO 105 series, using a multichotomous ordinal scale: the grey scale. The statistics were based on the ISO 13528 standard. The information provided in the surveys and 7,517 results from 40 laboratories in 20 countries were reviewed, proving that, although it is a visual determination, there is a strong consensus in the issuance of the results.  Participated in the exercise organized by PROSAFE for the detection by gas chromatography of phthalates limited in Regulation (EC) 1907/2006 and provided by the Netherlands Food and Consumer Product Safety Authority (NVMA), within the framework of the action joint JA China II cooperation with the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) of the People's Republic of China.  Participated in the evaluation of the performance of the methodology developed by the Korean entity KOTITI Testing & Research Institute, for the quantitative determination of fibre mixtures through cellulose carbonization, a process organized by the ISO/TC38/WG22 group for publication in the ISO standard. 1833-27, in which 10 laboratories from 6 countries participated: Japan, Italy, Portugal, Korea, France and Spain. Furthermore, the repeatability and reproducibility of the method was determined according to the ISO 5725-2 standard. The implementation of the work procedures and the results achieved in this doctoral thesis allow increasing the operational capacity of the LCG for the detection of unsafe products; in addition to highlighting his work as an EA supplier. Finally, it should be noted that, in the description of the LCG in Chapter I of this thesis, a parallel legal investigation arose into its origin, which was awarded the XXIV Manuel Colmeiro Research Prize

[gl] Nesta tese doutoral abórdase o estudo sobre diferentes exercicios de inter-comparación -a provisión de ensaios de aptitude (EA) no marco de campañas de control do mercado coa participación de 50 laboratorios de 24 países: Arabia Saudí, Arxentina, Bangladesh, Bélxica, Bosnia e Hercegovina, Bulgaria, Canadá, China, Colombia, Costa de Marfil, Croacia, Cuba, España, Italia, Lituania, Marrocos, Moldavia, Paquistán, Portugal, Reino Unido, Serbia, Turquía, Estados Unidos e Xordania e a participación en exercicios colaborativos- que foron realizados no Laboratorio de Consumo de Galicia (LCG), salientando a figura do provedor e poñendo especial fincapé no intercambio de información e na colaboración como vías para mellorar a calidade dos resultados.  Provéronse varias rondas do EA para a avaliación da identificación de fibras téxtiles. Na preparativa empregouse a microscopía óptica e de varrido electrónico, ensaios de solubilidade e espectroscopía infravermella; metodoloxías descritas no CEN ISO/TR 11827, en cuxa revisión se participou a través do grupo CEN/TC248/WG30. A avaliación realizouse segundo a ISO 13528. Estudáronse 1.480 resultados de 47 laboratorios de 21 países e a información de enquisas, constatándose que a experiencia e a combinación de técnicas son clave para a correcta identificación.  Provéronse varias rondas do EA para a avaliación da determinación cuantitativa da composición dos produtos téxtiles segundo os procedementos descritos na serie ISO 1833; métodos harmonizados co Regulamento (UE) 1007/2011, de conformidade co mandato M/532 da Comisión Europea, proceso no que se participou a través do grupo CEN/TC248/WG30. A avaliación realizouse segundo a ISO 13528 e co método gráfico Naji- Plot. Estudáronse 872 resultados de 47 laboratorios de 21 países e a información obtida de enquisas, detectándose diferenzas na interpretación da normativa técnica. Analizáronse 494 incertezas, determinándose que existe unha relación entre os resultados discrepantes e un inadecuado cálculo da incerteza.  Provéronse varias rondas do EA para a avaliación da determinación cualitativa da solidez da cor mediante a serie ISO 105, co emprego dunha escala ordinal multicotómica: a escala de grises. A estatística baseouse na ISO 13528. Revisouse a información dada nas enquisas e 7.517 resultados de 40 laboratorios de 20 países, constatándose que, aínda sendo unha determinación visual, existe un forte consenso na emisión dos resultados.  Participouse no exercicio organizado por PROSAFE para a detección por cromatografía de gases dos ftalatos limitados no Regulamento (CE) 1907/2006 e provisto pola Autoridade de Seguridade Alimentaria e de Produtos de Consumo dos Países Baixos (NVMA), no marco da acción conxunta de cooperación JA China II coa Administración Xeral de Calidade, Supervisión e Corentena (AQSIQ) da República Popular de China.  Participouse na avaliación do desempeño da metodoloxía desenvolvida pola entidade coreana KOTITI Testing & Research Institute, para a determinación cuantitativa de mesturas de fibras mediante carbonización da celulosa, proceso organizado polo grupo ISO/TC38/WG22 para a súa publicación na ISO 1833-27, no que participaron 10 laboratorios de 6 países: Xapón, Italia, Portugal, Corea, Francia, e España. Tamén determinouse a repetibilidade e reproducibilidade do método segundo a ISO 5725-2. A aplicación dos procedementos de traballo e dos resultados acadados nesta tese doutoral permiten incrementar a capacidade operativa do LCG para a detección de produtos inseguros, así como; salientar a súa labor como provedor de EA. Por último, cabe destacar que, na descrición do LCG no Capítulo I desta tese xurdiu unha investigación xurídica paralela sobre a súa orixe, que foi galardoada co XXIV Premio de Investigación Manuel Colmeiro.