How can I cancel killing a player when touching a part?

I am making a space theme game. When I go out I lose oxygen and start to suffocate and my screen turns blurry, like I am passing out. The good news it works very good even in an online game, the bad news I dont know how to prevent a player from dying after he touches a part that "has oxygen".

local blur = game.Lighting.Blur

script.Parent.Touched:connect(function()
	blur.Enabled = false
end)


script.Parent.TouchEnded:connect(function()
	blur.Enabled = true
	blur.Size = 2
	wait(0.3)
	blur.Size = 4
	wait(0.3)
	blur.Size = 6
	wait(0.3)
	blur.Size = 8
	wait(0.3)
	blur.Size = 10
	wait(0.3)
	blur.Size = 12
	wait(0.3)
	blur.Size = 14
end)
script.Parent.TouchEnded:connect(function(hit)
	wait(5)
	if hit and hit.Parent and hit.Parent:FindFirstChild("Humanoid") then
 		hit.Parent.Humanoid.Health = 0
 	end   
end)

I already made a script of killing a player when he untouches a part, but when I touch the part again he still dies. Can anyone help me? How to stop run a line of code to prevent what will happen next?

-- The Bool Value setup 

game:GetService("Players").PlayerAdded:Connect(function(plr)
    local touchedPart = Instance.new("BoolValue", plr)
    touchedPart.Name = "TouchedOxygen" -- Change the name
    touchedPart.Value = false -- Change to true when they step on the oxygen
end)