The most accurate translation would depend on the exact context. Here are a few options, with slight variations:

* **افتتاح أسبوع السلامة والصحة المهنية في مستشفى جامعة أوسلو (OUS)** (Iftitah Usbu’ as-Salamah wa as-Sihhah al-Mihaniyyah fi Mustashfa Jami’at Oslo (OUS)) – This is a very literal and formal translation, suitable for official documents. It translates to “Opening of the Occupational Safety and Health Week in Oslo University Hospital (OUS).”

* **انطلاق فعاليات أسبوع السلامة المهنية في OUS** (Intilaq Fa’aliyat Usbu’ as-Salamah al-Mihaniyyah fi OUS) – This translates to “The Launch of Occupational Safety Week Activities in OUS”. It’s a more dynamic and common way to express the opening of an event.

* **بدء فعاليات أسبوع بيئة العمل الصحية في OUS** (Bad’ Fa’aliyat Usbu’ Bi’at al-‘Amal as-Sihhiyya fi OUS) – This translates to “Beginning of Healthy Work Environment Week Activities in OUS.” This is a bit looser, focusing on the “healthy work environment” aspect.

* **تدشين أسبوع السلامة والصحة المهنية في مستشفى جامعة أوسلو** (Tadshin Usbu’ as-Salamah wa as-Sihhah al-Mihaniyyah fi Mustashfa Jami’at Oslo) – This uses “tadshin” which means inauguration/launch.

**Which one to use?**

* If you need to be very formal and precise, use the first or last option.
* If you want a more common and easily understood phrase, use the second or third option.

In all cases, “OUS” is likely best kept as is, as an abbreviation well-known. “Oslo University Hospital” could be written in Arabic also as “مستشفى جامعة أوسلو” (Mustashfa Jami’at Oslo).