EDPB, Guidelines 3/2019 on Processing of Personal Data through Video Devices (2020).
22.214.171.124 “state of the art”
18. The concept of “state of the art” is present in various EU acquis, e.g. environmental protection and product safety. In the GDPR, reference to the “state of the art”  is made not only in Article 32, for security measures, but also in Article 25, thus extending this benchmark to all technical and organisational measures embedded in the processing.
 See German Federal Constitutional Court’s “Kalkar” decision in 1978: https://germanlawarchive.iuscomp.org/?p=67 may provide the foundation for a methodology for an objective definition of the concept. On that basis, the “state of the art” technology level would be identified between the “existing scientific knowledge and research” technology level and the more established “generally accepted rules of technology”. The “state of the art” can hence be identified as the technology level of a service or technology or product that exists in the market and is most effective in achieving the objectives identified.
19. In the context of Article 25, the reference to “state of the art” imposes an obligation on controllers, when determining the appropriate technical and organisational measures, to take account of the current progress in technology that is available in the market. The requirement is for controllers to have knowledge of, and stay up to date on technological advances; how technology can present data protection risks or opportunities to the processing operation; and how to implement and update the measures and safeguards that secure effective implementation of the principles and rights of data subjects taking into account the evolving technological landscape.
20. The “state of the art” is a dynamic concept that cannot be statically defined at a fixed point in time, but should be assessed continuously in the context of technological progress. In the face of technological advancements, a controller could find that a measure that once provided an adequate level of protection no longer does. Neglecting to keep up to date with technological changes could therefore result in a lack of compliance with Article 25.
21. The “state of the art” criterion does not only apply to technological measures, but also to organisational ones. Lack of appropriate organisational measures can lower or even completely undermine the effectiveness of a chosen technology. Examples of organisational measures can be adoption of internal policies; up-to date training on technology, security and data protection; and IT security governance and management policies.
22. Existing and recognized frameworks, standards, certifications, codes of conduct, etc. in different fields may play a role in indicating the current “state of the art” within the given field of use. Where such standards exist and provide a high level of protection for the data subject in compliance with – or go beyond – legal requirements, controllers should take them into account in the design and implementation of data protection measures.
(EN) ISO/IEC 27701, adopted in 2019, added additional ISO/IEC 27002 guidance for PII controllers.
Here is the relevant paragraph to article 32(1)(a) GDPR:
7.4.5 PII de-identification and deletion at the end of processing
The organization should either delete PII or render it in a form which does not permit identification or re-identification of PII principals, as soon as the original PII is no longer necessary for the identified purpose(s).
The organization should have mechanisms to erase the PII when no further processing is anticipated.