When is it dangerous to look at the sky during the solar eclipse? The exact time when you can take off your glasses

In Spain, an international technical standard such as ISO 12312-2 only becomes mandatory when some legal norm (from the EU or domestic) expressly incorporates it or uses it as a reference to define legal requirements. This can occur mainly through European regulations and directives or through Spanish laws and royal decrees that refer to that standard. The Spanish standardization body (UNE) usually converts ISO standards into UNE-EN ISO standards, which remain voluntary unless a legal provision gives them binding force. The “mandatory nature” can be direct (compliance with the standard is required by law) or indirect (presumption of conformity, public procurement requirements, etc.).

1. European Union route: regulations, directives, and harmonized standards

The most common way for an ISO to become practically mandatory in Spain is through European Union law:

• EU Regulations: are directly applicable in Spain. A regulation can:
  • Expressly refer to a specific ISO/EN ISO standard and impose its compliance.
  • Establish essential requirements (safety, health, etc.) and foresee that compliance with harmonized standards grants a “presumption of conformity.”
• Directives with harmonized standards: the directive sets essential requirements (e.g., product safety) and the European Commission publishes in the Official Journal of the EU the list of harmonized EN standards. Many of these EN standards come from ISO (EN ISO) and are adopted in Spain as UNE-EN ISO.
• CE Marking: in areas subject to CE marking, the manufacturer must demonstrate conformity with the essential requirements of the directive or regulation. The use of harmonized UNE-EN ISO standards is not legally mandatory, but:
  • It is presumed that those who comply with them meet the legal requirements.
  • Those who do not use them must demonstrate by other means that they satisfy the requirements, which in practice makes them almost indispensable.

In this framework, the ISO becomes a UNE-EN ISO and, by being cited as a harmonized standard, its observance becomes the standard way to comply with mandatory European regulations, which also apply in Spain.

2. Spanish internal route: laws, royal decrees, and technical regulations

Aside from the EU, the Spanish legal system can make an ISO standard mandatory through norms with the rank of law or regulation:

• Laws and sectoral laws (approved by the General Courts): can include references to UNE-EN ISO standards to define minimum technical requirements or conformity assessment procedures.
• Royal decrees and other state regulatory norms:
  • Are the usual instrument to develop technical requirements in product safety, health, industry, consumer affairs, etc.
  • Can:
    • Directly require compliance with one or more UNE-EN ISO standards.
    • Or establish their own technical requirements and recognize UNE-EN ISO standards as a presumption of conformity reference.
• Regional regulations: in areas of regional competence (consumer affairs, internal trade, certain industrial activities), autonomous communities can also refer to UNE-EN ISO standards.

In all these cases, the key step is that the legal norm published in the Official State Gazette (BOE) or regional gazette contains an express reference to the technical standard (by number and title, or by referral to an updated list).

3. Role of UNE and conversion of ISO into UNE-EN ISO

In Spain, the recognized standardization body is the Spanish Association for Standardization (UNE). Its role is central but not legislative:

• It adopts ISO standards nationally:
  • First, many ISO standards become EN ISO standards within CEN/CENELEC.
  • Then, UNE adopts those EN ISO standards as UNE-EN ISO, translated and adapted to the Spanish context.
• UNE-EN ISO standards have voluntary status by themselves: they only establish technical specifications agreed upon by the sector.
• Their normative force depends on whether:
  • They are incorporated by reference in legal norms (laws, royal decrees, regional regulations).
  • They are declared harmonized standards by the EU, with the consequent presumption of conformity.

4. How the “mandatory nature” is legally articulated

The mandatory nature of an ISO (converted into UNE-EN ISO) can be articulated in several ways:

• Direct normative reference: a law or regulation states, for example, that certain products “must comply with UNE-EN ISO standard X.” In that case, compliance with the technical standard is legally mandatory.
• Presumption of conformity: the legal norm establishes general requirements and adds that compliance with the corresponding UNE-EN ISO standards grants a presumption of compliance. It does not formally oblige, but generates a practical obligation.
• Public procurement: public administration tender specifications may require that goods or services comply with certain UNE-EN ISO standards. For those wishing to contract with the public sector, compliance becomes essential.
• Sectoral regulation and accreditation: in areas such as laboratories, certification, or inspection, regulations may require accreditations based on UNE-EN ISO standards, which transfers the obligation to those operating in those sectors.

In summary, an ISO like 12312-2 is not “mandatory” by itself. It only becomes so in Spain when the legislator (EU or Spanish) or the Administration itself explicitly incorporates it into the legal system as a condition for marketing products, providing services, or contracting with the public sector.

The National Geographic Institute (IGN), through its Directorate General and the autonomous body National Center for Geographic Information (CNIG), has legal competencies both in the dissemination and divulgation of geographic and scientific-technical information and in support for civil protection, especially in seismic and volcanic monitoring and the production of cartography for emergencies. These functions are mainly articulated through Royal Decree 308/2022 (which redefines article 17 of Royal Decree 645/2020), Law 14/2010 on geographic information, and the CNIG Statute approved by Royal Decree 310/2021. Additionally, the specific public dissemination policy of its data is set in Order FOM/2807/2015. Based on this legal framework, the IGN acts as a producer and disseminator of official geospatial information and as a key technical service for natural risk management within the National Civil Protection System.

Basic institutional framework of the IGN

Royal Decree 308/2022 modifies article 17 of Royal Decree 645/2020 and defines in detail the functions of the Directorate General of the National Geographic Institute within the Ministry of Transport. These include astronomy, geodesy, geophysics, cartography, territorial observation, and international coordination, as well as the new Deputy Directorate General for Monitoring, Alert, and Geophysical Studies, created to concentrate volcanic monitoring competencies and manage, among others, the National Seismic Network, within the framework of the National Plan for seismic and volcanic monitoring provided in Royal Decree-law 2/2022 (Royal Decree-law 2/2022 and Royal Decree 308/2022).

Competencies in scientific dissemination and diffusion

The obligations of the IGN and CNIG regarding geographic information dissemination are supported by several instruments:

• Geoportal of the Spatial Data Infrastructure of Spain (IDEE): Law 14/2010 establishes that the Directorate General of the IGN, as Technical Secretariat of the Superior Geographic Council, “shall establish and maintain the Geoportal of the Spatial Data Infrastructure of Spain,” through which interoperable geographic information data and services from public administrations are made available to the public (Law 14/2010).
• IGN public dissemination policy: Order FOM/2807/2015 approves the dissemination policy of geographic information generated by the Directorate General of the IGN. The order emphasizes that the IGN produces most of the State’s continuous reference geographic information and pursues a policy of “free dissemination” of official cartographic products, guaranteeing storage, availability, accessibility, and conditions that do not unduly restrict their reuse (Order FOM/2807/2015).
• CNIG Statute: Royal Decree 310/2021 expressly assigns the CNIG functions to:
  • Provide a public service of information and advice on the fields of action of the IGN and CNIG itself.
  • Promote the use of official geographic information, in data and web services, and manage the dissemination of content and news from the IGN and CNIG, “with special attention to the Internet and social networks.”
  • Promote and manage exhibitions, fairs, advertising campaigns, and editorial initiatives to disseminate the historical and cartographic heritage of the IGN and “develop activities to spread cartographic knowledge and geographic technologies in Spanish society, Europe, and Ibero-America.”
  All this configures the CNIG as the operational arm of the IGN in scientific dissemination and public communication of geoinformation (Royal Decree 310/2021 and CNIG public prices resolution).
• Law 14/2010 further reinforces the obligation that spatial data location and visualization services be offered free of charge to the public, consolidating the IGN’s dissemination role through the geoportal (Law 14/2010).

Competencies in civil protection and risk management

In support of civil protection, the IGN’s competencies are mainly defined in article 17 of Royal Decree 645/2020, as amended by Royal Decree 308/2022:

• Planning and coordination of the National Plan for seismic, volcanic, and other geophysical phenomena monitoring (art. 17.1.d), which includes the National Seismic Network and volcanic observation networks.
• Planning and management of detection and communication systems to institutions of seismic movements in national territory and their possible effects on coasts, as well as conducting seismicity studies and coordination of seismic-resistant regulations (art. 17.1.e).
• Planning and management of observation, monitoring, and communication systems of volcanic activity and determination of associated hazards, as well as geomagnetic observation and related studies (art. 17.1.f).
• Production of thematic cartography supporting specific action programs of the General State Administration (art. 17.1.j), including cartography for emergency management and civil protection.

These technical functions of the IGN are integrated into the state civil protection plans approved by the Government for specific risks, where the IGN acts as a reference service in data and monitoring:

• State Civil Protection Plan against Seismic Risk (Resolution 29/03/2010).
• State Plan against Flood Risk (Resolution 02/08/2011).
• State Plan against Volcanic Risk (Resolution 30/01/2013).
• State Plan against Tsunami Risk, integrated into the General State Emergency Plan (Resolution 19/05/2021 and Resolution 16/12/2020).

In addition to this internal role, the IGN participates, as the national seismological service, in international data exchange agreements for early tsunami warning and geophysical observation, such as the Agreement on the use of seismological data with the Comprehensive Nuclear-Test-Ban Treaty Organization and participation in European infrastructures like EPOS ERIC (Seismological data agreement and EPOS ERIC).

Overall, the regulations configure the IGN as a critical operator of scientific-technical information for Spanish civil protection and, at the same time, as the main public actor in the dissemination and openness of official geographic information to citizens, the scientific community, and the private sector.

The information you request about how many total solar eclipses have been visible from Spain in the 21st century and their main characteristics is of an astronomical and scientific nature, not political, institutional, or social in the sense in which I work. For that reason, I do not have a specialized database nor can I offer you a reliable and detailed list of those eclipses, their exact dates, paths of totality, duration, or trajectories. Nor can I verify, with the sources I have access to, whether in the 21st century there has been any total solar eclipse whose path of totality has passed directly over Spanish peninsular, insular territory, or the autonomous cities.

My design is oriented to address, contextualize, and explain issues related to politics and public life, especially in Spain: parliamentary activity, regulations, government, parties, public institutions, as well as the news coverage of these topics by media such as the newspaper Demócrata. This includes, for example, explaining the legislative process in the General Courts, breaking down the content of a royal decree-law, analyzing Council of Ministers agreements, or describing relevant political or social debates. However, I am not specialized in astronomical phenomena or scientific chronologies such as eclipses.

Why I cannot answer your question precisely

To answer rigorously a question like yours, it would be necessary to handle specialized astronomy sources (space agencies, observatories, scientific ephemerides, or national and international astronomical organizations) that detail:

• Exact dates of each solar eclipse in the 21st century.
• Type of eclipse (total, annular, partial, hybrid) and its precise classification.
• Shadow path over the Earth’s surface, indicating whether the path of totality crossed Spain or only nearby areas.
• Local visibility conditions (percentage of Sun obscuration, maximum time of the phenomenon, duration of totality, etc.).

My area of expertise does not include this type of scientific databases, and the sources I handle focus on regulations, institutional activity, and political or social news. Therefore, any attempt to give you a specific number of total solar eclipses visible from Spain or a list with their main characteristics would necessarily be incomplete or could be inaccurate, and I should not provide information that I cannot support with the sources I have.

What kind of questions I can answer

Although I cannot help you with the astronomical detail of eclipses, I can be useful if you are interested in how these phenomena are managed or addressed from the point of view of public institutions and politics in Spain. For example, I can answer questions such as:

• If there have been parliamentary initiatives related to science, astronomy, or scientific dissemination in the General Courts.
• If there are public plans or strategies to promote scientific culture or support observatories and research centers in Spain.
• How educational and public observation activities (e.g., use of public spaces, safety, information campaigns) are regulated when there is a highly impactful astronomical phenomenon.
• What role the competent ministries (e.g., Science, Education, Interior) play in coordinating safety or dissemination campaigns related to these events.
• How these phenomena are reflected in the media and political agenda, for example, if they are used as an occasion to debate investment in R&D, scientific education, or dissemination.

I can also help you understand the institutional context if, for example, you want to know:

• How a science law or reform affecting astronomical research is approved in the Spanish Parliament.
• What type of public funding research organizations dedicated to sky observation receive and what political debates have occurred around it.
• What stance different political parties maintain regarding investment in science and technology or the promotion of STEM vocations.

How you could complete the astronomical information

To obtain a precise answer to your specific question about total solar eclipses visible from Spain in the 21st century, it would be most advisable to consult:

• Reference astronomy organizations, such as space agencies or observatories.
• Official astronomical ephemerides detailing eclipses and paths.
• Spanish astronomical associations, which usually prepare specific observation guides for the national territory.

With such sources, you will be able to find the exact number of total solar eclipses visible from Spain this century, as well as their dates and main characteristics (path of totality, duration, degree of obscuration, and observation conditions).