| time | awards | |
| 2020 | iso-45001:2018, 2020 sgs certified | |
| 2017 | iso-14001:2015, 2017 sgs certified |  |
| 2013 | ohsas-18001:2007, 2013 dnv certified | |
| 2010 | ohsas-18001:2007, 2010 dnv certified | |
| 2005 | iso-14001:2004, 2005 dnv certified | |
| 2004 | ohsas-18001:1999, 2004 dnv certified | |
| 1996 | iso-14001:1996, 1999 dnv certified | |
