Privacy policy for the UN Number app

Last updated: September 2026

1. What this policy covers

This privacy policy covers our mobile app UN Number for iOS and Android. Our website has a policy of its own: https://zweidenker.de/en/privacy-policy/.

The app makes UN numbers, ERI cards and the data sheets of the “Hommel” manual available on a phone or tablet. You need no account for that: there is no registration, no sign-in and no user profile held by us.

All substance data is contained in the app. Looking up a number works entirely offline; no server of ours is queried in the process, and we do not learn what you search for. Connections to the internet are made only by the services described in sections 4 to 8.

2. Controller

The controller for the data processing in this app is:

ZWEIDENKER Holding GmbH
Brüsseler Platz 26
50674 Cologne
Germany

Phone: +49 221 56078098
Email: kontakt@zweidenker.de

The controller is the natural or legal person who alone or jointly with others determines the purposes and means of processing personal data.

3. What stays on your device only

The app stores on your device:

  • the two switches from the settings (“Send Analytics Data” and “Send Crash Reports”)
  • the language chosen for the interface and the data
  • a counter of how often you have looked up a number (see section 9)
  • whether a valid purchase of UN Plus exists

None of this leaves your device, none of it is accessible to us, and all of it is deleted when you uninstall the app.

4. Usage analysis with Firebase Analytics

The app uses Google Analytics for Firebase so that we can see which functions are used and where the app is awkward to operate. For users in the European Economic Area the provider is Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland.

The following is transmitted:

  • which screens of the app you open
  • which UN number you opened, together with the number of the corresponding ERI card
  • whether the numeric keypad was expanded or collapsed
  • the completion of a purchase including the product chosen, and a request to restore earlier purchases
  • as persistent properties of the installation: the status of your UN Plus access (monthly, yearly, permanent, none or business) and the language selected

In addition, Google collects technical details about the installation, in particular an app instance identifier assigned by Google, the device model, the operating system and app version, the time of use, and your IP address, from which Google derives an approximate location (usually country or region).

None of this names you as a person — no name, no email address, no phone number. We evaluate the data in aggregate.

You can switch the transmission off at any time: in the app under Settings → “Send Analytics Data”. Analytics is on when the app is installed; once switched off, nothing further is sent to Firebase Analytics.

The legal basis is Art. 6(1)(f) GDPR. Our legitimate interest lies in being able to improve the app in a targeted way. Transfer to the USA cannot be ruled out.

Further information: https://firebase.google.com/support/privacy and https://policies.google.com/privacy.

5. Crash reports with Firebase Crashlytics

If the app crashes or an error occurs, it sends a report to Firebase Crashlytics so that we can reproduce and fix the error. The provider is again Google Ireland Limited (address in section 4).

Such a report contains:

  • the type and time of the error and the program flow leading up to it (stack trace)
  • the app version, the device model and the version of the operating system
  • two additional values we set ourselves: the UN number that was on screen at the time, and the section of the ERI card in which the error occurred
  • an installation identifier assigned by Crashlytics

A crash report contains no names, email addresses or contact details.

This can be switched off as well: under Settings → “Send Crash Reports”. Reports are on when the app is installed.

The legal basis is Art. 6(1)(f) GDPR. Our legitimate interest lies in the stability of an app that has to work reliably when it is needed. Transfer to the USA cannot be ruled out.

6. Feedback via Wiredash

In several places in the app — on the input screen and on error messages — you will find a “Give Feedback” button. It opens a form provided by the Wiredash service. The provider is Wiredash GmbH; the data is processed on Google Cloud Platform servers.

Feedback is sent only when you initiate it. What is transmitted then:

  • your message
  • your email address, if you enter it in the form — the field is optional
  • a screenshot of the screen, if you capture and annotate one yourself
  • technical details about the installation: app and build version, app identifier (bundle ID), device model, operating system and its version, the device language and locale settings, screen size and display settings, light or dark mode, and an installation identifier

The legal basis is Art. 6(1)(a) GDPR — you decide about the transmission by sending the form — together with Art. 6(1)(f) GDPR for handling your feedback. We use your feedback solely to improve the app and, where applicable, to reply to you.

Independently of that, the Wiredash SDK contacts api.wiredash.io when the app starts to retrieve its configuration — at most once every 30 minutes. A usage identifier, the app and build version, the app identifier, the operating system and its version, the language setting and the SDK version are transmitted in the process. This call cannot be switched off in the app; the legal basis is Art. 6(1)(f) GDPR in a working feedback channel.

Wiredash privacy policy: https://docs.wiredash.com/company/privacy.

7. Purchases in the App Store and on Google Play

Additional functions are bundled as UN Plus, available as a monthly or yearly subscription. Content bought individually in the past — Hommel data sheets, ADR information and the hazard diamond — remains unlocked permanently.

Purchase, billing, renewal and cancellation are handled exclusively by the Apple App Store or by Google Play. We receive no payment data, no bank details, no card number, no billing address. The app only asks the store whether a valid purchase exists and stores the answer on the device.

Restoring earlier purchases is likewise handled by the respective store. On iOS 14 and later the app can additionally open Apple’s sheet for redeeming voucher codes; to determine that, it reads the version of the operating system.

For the processing in the store, the privacy policy of the respective provider applies: Apple Distribution International Ltd., Hollyhill Industrial Estate, Hollyhill, Cork, Ireland, and Google Ireland Limited (address in section 4).

8. Review prompt

After the 10th, 20th and 40th lookup, the app asks the operating system to show its own review dialog. The counter for this lives on your device alone. Whether the dialog actually appears is up to the operating system; whether and how you rate the app is not something we learn — the rating itself is received by Apple and Google.

9. No advertising, no permissions

  • The app shows no advertising and integrates no ad network.
  • There is no cross-app tracking. The app therefore does not ask for tracking permission on iOS (App Tracking Transparency) and uses no advertising identifier.
  • The app requests no access to the camera, microphone, location, contacts, calendar or photos. On Android, besides internet access, it needs only the permission for in-app purchases.

From the settings, the app opens this page in your browser. From that point on, the privacy policy for our website applies (https://zweidenker.de/en/privacy-policy/).

11. Your rights

Within the scope of the applicable legal provisions, you have the right at any time to obtain free information about your stored personal data, its origin and recipients and the purpose of the processing, and where applicable a right to have this data corrected, deleted or its processing restricted. You also have the right to data portability.

Where processing is based on your consent, you may withdraw that consent at any time. The lawfulness of the processing carried out until the withdrawal remains unaffected.

You also have the right to object at any time, on grounds relating to your particular situation, to processing based on Art. 6(1)(f) GDPR (Art. 21 GDPR).

For all of these matters please write to the address given in section 2 or to kontakt@zweidenker.de. Please note that without additional details we can generally not link your use of the app to a person — to answer a request for information we therefore need details that allow your data to be found.

12. Right to complain to the supervisory authority

In the event of infringements of the GDPR, data subjects have the right to lodge a complaint with a supervisory authority, in particular in the Member State of their habitual residence, place of work or the place of the alleged infringement.

The supervisory authority responsible for us is the Landesbeauftragte für Datenschutz und Informationsfreiheit Nordrhein-Westfalen, Kavalleriestr. 2–4, 40213 Düsseldorf, Germany.

13. Disclaimer and terms of use

This page governs data protection. The disclaimer for the content shown — the data is based on the freely available Emergency Response Intervention Cards (ERI cards) published by Cefic and is neither certified nor otherwise approved by them — is shown by the app on first launch and afterwards at any time under Settings → Disclaimer. For purchases, the terms of use of the Apple App Store or Google Play apply in addition.

14. Changes to this policy

We adapt this policy when the app changes — for instance when a service is added or removed. The version published here is the one that applies; the date at the top of the page states when it was last updated.