2. Gasunie is one of the biggest gas infrastructure companies in Europe. Within the company, we give safety the highest priority; it forms the basis of our license to operate. We abide by the strictest safety, health and environmental standards, both for our own employees, external contractors and the surroundings. Gasunie’s safety policy is thus characterised by a proactive approach which is designed to prevent accidents, incidents and hazardous situations.

3. Hazardous substances Strict procedures are applied to work on closed installations and systems since there is a risk of harmful substances being released. Please therefore read the procedures or work permit carefully before beginning the work, and check on site whether the control measures described are in place. Put in place the precautionary measures that apply to the implementation of the work. Remain alert to the possibility of increased concentrations of harmful substances at all times. Never start work without the express permission of the site supervisor. Remain alert at all times when you are working. If in any doubt, always ask or suspend activities where necessary.

4. Working with nitrogen The atmosphere consists of approximately 78% nitrogen. At Gasunie, nitrogen is added to natural gas to make it suitable for use by Dutch households. The nitrogen required is supplied via a pipeline or abstracted from the air outside. The second of these procedures takes place in air separation units, where nitrogen is converted into liquid. Liquid nitrogen is also referred to as LIN (liquefied nitrogen). Risks of working with nitrogen Exposure to excessive amounts of nitrogen is a risk to health because it displaces oxygen. Overly high concentrations of nitrogen in the air can even lead to death. Skin contact with liquid nitrogen can cause burning. This calls for maximum alertness whenever you are working with nitrogen. Nitrogen at Gasunie locations At Gasunie, work with nitrogen occurs at various locations.

5. Gaseous nitrogen occurs: During the rinsing and conserving (purging) of installations and pipelines in the underground storage facility at Heiligerlee in the Wieringermeer compressor and blending station in the blending station at Ommen in the blending station and LNG evaporators on the Maasvlakte in the Pernis blending station in the Kootstertille and Zuidbroek air separation units and blending Liquid nitrogen (LIN) occurs: in the Ommen, Zuidbroek and Kootstertille air separation units during the liquification and storage of LNG on the Maasvlakte Properties of nitrogen: colourless odourless oxygen-displacing asphyxiating

6. Risks of exposure to nitrogen Liquid nitrogen is extremely cold (- 196 ˚ C) and is also caustic. Nitrogen in gaseous form displaces oxygen and therefore causes shortage of breath or asphyxiation. ExposureAcute effects GeneralNitrogen displaces oxygen Eyes (LIN)Risk of freezing: redness, soreness, blurred vision InhalationBreathlessness Headache, dizziness, nausea Unconsciousness, death through asphyxiation Skin (LIN)Risk of freezing: redness, soreness, blisters, wounds Risks of nitrogen leaks in a largely confined space A leak can cause nitrogen to be released into the atmosphere. Nitrogen displaces oxygen and can therefore have disastrous effects.

7. Oxygen concentration Potential effects 21-18%No symptoms (investigate cause of declining oxygen content!) 18-11%Uncomfortableness: dizziness, headache, reduced physical and mental capacity, reduced reasoning and speaking capacity 11-8%Unconsciousness after a few minutes 8-6%Unconsciousness very soon following 2 to 3 inhalations, resuscitation possible if performed quickly 6-0%Swift asphyxiation: immediate unconsciousness, brain damage even after resuscitation, death No risks for the environment Nitrogen that is inhaled from the open air does not pose a danger to the environment! The leaked nitrogen will mix with the ambient air which already consists of nearly 80% nitrogen. Liquid nitrogen will evaporate and also be absorbed into the air (1 litre of liquid nitrogen will give 600 litres of gaseous nitrogen).

8. First aid on contact with nitrogen ExposureFirst aid GeneralWhen reviving casualties, always use only independent breathing equipment! Eyes (LIN)Rinse out with plenty of cold and clean water Remove contact lenses (if possible) Consult ophthalmologist Skin (LIN)Rinse with plenty of cold, clean water Never pull off clothes that are stuck to the body Inhalation (gas)Using independent breathing equipment, remove the casualty from the nitrogen-filled environment Call in medical help without delay Apply artificial respiration until professional help arrives

9. What to do in the event of a leak Evacuate the site away from the direction of the wind Report any leaks to the location supervisor or issuer of the work permit Notify any casualties immediately to the location supervisor or issuer of the work permit Never re-enter the area to rescue casualties without independent breathing equipment! What personal protection equipment to use? In addition to the standard personal protection equipment (PPE: safety helmet, goggles, protective jacket, trousers and shoes), additional PPE are needed for work in nitrogen-containing environments. These are mainly designed to prevent asphyxiation (on inhalation) and skin contact with liquid nitrogen (LIN). The relevant PPE are as follows:

10. In the event of reduced oxygen levels: personal oxygen metre independent breathing apparatus In the event of work involving liquid nitrogen: personal oxygen metre sealable work clothing face visor /full-face mask cryogen-proof gloves cryogen-proof apron

11. Supplementary safety rules A work permit is always required for work carried out in a ‘nitrogen environment’ Work on nitrogen-containing systems or machinery may only take place once these installations have been secured (blocked, locked and labelled) Check the ventilation of the workspace Check the oxygen level of the workspace Ensure that you are aware of the risks associated with the work Discuss these risks with the supervisor/client Take the necessary precautionary measures Use all the personal protection equipment cited in this folder Assume responsibility! Everyone, before they start work, must check the safety of systems and appliances. If you have any doubts or uncertainties, ask for an explanation! Contact the issuer of the work permit.