75
Phosphorus(V) oxide
P2O5
Also known as phosphorus pentoxide and diphosphorus pentoxide.
Corrosive
R35: Causes severe burns.
-3
WEL (mg m ): 1.0 (LTEL), 2.0 (STEL).
C
The substance is
dangerous with:
WATER. A violent reaction occurs. Any combustible material in the vicinity may even ignite.
METHANOIC ACID. Carbon monoxide is given off.
SODIUM, POTASSIUM. These metals may ignite on contact.
IODIDES. A violent reaction occurs.
Store: CS
Place this in a desiccator or other outer container with
anhydrous calcium chloride. Keep small quantities (250 g
or less), so that stock is always fresh.
Disposal: W1, W4
W4:
Use a fume cupboard. Add 10 g of solid in
-3
about 1 g portions to 1 litre of 1 mol dm
sodium carbonate solution. Carry this out slowly
because the reaction produces gases and heat.
Pour down a foul-water drain.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard.
© CLEAPSS 2007
75
Phosphorus(V) oxide
Activity
Addition to
water
Preparation of
acid
anhydrides
Use as a
drying agent
User
Y9
Control measures
Wear goggles.
Y12
Wear goggles.
Wear chemical-resistant
gloves.
Use a fume cupboard.
Wear goggles or a face
shield.
Wear chemical-resistant
gloves.
TT
Model risk assessments
Experimental points
3
Add 0.1 g of phosphorus(V) oxide to 2 cm of water. The
reaction is very vigorous.
-
Take care disposing of the used solid. A glassy crust often
forms, concealing dry oxide which will react violently with water.
It must not be reused. Safer alternatives include silica gel
(easily re-used) and saturated calcium chloride solution.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard.
© CLEAPSS 2007