56
Lead metal, lead carbonate, oxides and sulfide
Lead metal
Lead(II) carbonate
Lead(II) oxide
Lead(IV) oxide
Dilead(II) lead(IV) oxide
Lead(II) sulfide
Toxic
T
Dangerous for the
environment
Store: T
N
(See also 57A & 57B)
Pb
Cerrusite
PbCO3
Lead monoxide; yellow lead; litharge; massicot
PbO
Lead dioxide
PbO2
Red lead
Pb3O4
Galena
PbS
R61: May cause harm to the unborn child. Category 1 teratogens. R62: Possible risk of
impaired fertility. R20/22: Harmful by inhalation and if swallowed. R33: Danger of
cumulative effects. R50/53: Very toxic to aquatic organisms, may cause long-term
adverse effects in the aquatic environment.
Dangerous with (oxides): ALUMINIUM, MAGNESIUM powders and ORGANIC
MATERIAL. Vigorous or explosive reactions may occur.
-3
WEL (mg m ): 0.15 (LTEL), 0.45 (STEL) as lead.
Disposal: W1, W2
Emergencies: see standard procedures on Hazcard E, BUT ALSO:
If spilt in the
Wear eye protection and chemical-resistant gloves. Scoop up as much solid as possible into a
laboratory
bucket. Rinse the area with water and clear up, washing water down a foul-water drain and
diluting further. Keep the solid for disposal using a licensed waste contractor.
Lead and its carbonate, oxides and sulfide may be of concern to those who are pregnant. In schools, however, they are
used in tiny quantities compared with their use in industry. There is little risk from simply using the chemicals. Inhalation is
a remote possibility if significant amounts of dust become airborne, hence care should be taken to avoid this. Swallowing
is unlikely if eating and drinking are totally banned in the laboratories/prep room and hands are washed after handling
these substances.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard.
© CLEAPSS 2007
56
Lead metal, lead carbonate, oxides and sulfide
Activity
Use of lead metal
Heating lead(II)
sulfide
Reduction of lead
oxides and ores
with carbon
User
Y7
Y7
Melting lead metal
Y7
Making ‘glass’
Y7
Preparation of
lead(IV) oxide
Y12
Wear goggles.
Showing lead
crystals
TT
Wear thermal gloves and eye
protection. Ensure good ventilation.
Y7
Control measures
Wash hands afterwards.
Wear eye protection.
Use a fume cupboard.
Wear eye protection.
Ventilate the room.
With bottle tops, technicians should
remove the plastic inserts by
strongly heating them.
Wear eye protection. Ventilate the
room. Tie long hair back.
Used blowpipes and rubber tubing
should be disinfected with Milton
solution before rinsing. Do not cool
charcoal blocks in water as they will
split.
Wear eye protection.
Wear thermal gloves.
Wear eye protection. Take care to
avoid raising dust of lead(II) oxide.
Model risk assessments
Experimental points
The metal will rub off on skin. Lumps of lead can be wrapped in Clingfilm.
Sulfur dioxide is also produced. Particles can shoot off during heating.
A mixture of 1 g of lead(II) oxide or lead(II) carbonate and 0.1 g of powdered
wood charcoal is heated strongly in a crucible. After 5 minutes, add another
0.1 g of charcoal. A prepared beer-bottle top also works well. Hot metal containers can be dropped into a glass beaker of cold water to prevent further
oxidation.
Blowpipe method: To reduce the amount blown into the air, mix the oxide or
ore with a little water to dampen them before placing the paste on the carbon
block. Rubber tubing can be connected to the blowpipe. After use, cool the
blocks in air. Used hot carbon blocks can cause fires when stacked. Store in
an air-tight metal container, eg, a biscuit tin. Alternatively, make a depression
in a piece of soft wood with a screwdriver and, using the blowpipe, char it
before adding damp lead oxide. Wood blocks can be doused in water.
Open windows to provide ventilation. Melting can be done in a beer-bottle top
(burn away the plastic insert) supported on a pipe-clay triangle.
This uses zinc oxide, lead(II) oxide and boric acid. Allow plenty of time for the
crucible to cool before immersing it in 1 mol dm-3 nitric(V) acid for cleaning.
For details, see Hazcard 14.
Add 4 cm3 of 5 mol dm-3 nitric(V) acid to dissolve 1 g of lead in a boiling tube,
warming it in a boiling-water bath. Neutralise with 2 mol dm-3 sodium hydroxide solution drop by drop until there is a faint white precipitate. Add 10 cm3 of
2 mol dm-3 sodium hydroxide and 6 cm3 of 10-14% sodium chlorate(I) solution
(CORROSIVE) and place in a boiling-water bath. Filter off the dark-brown precipitate and wash with water.
Pour a small pool of molten lead onto a ceramic tile to cool. The tile should be
in a wooden tray.
For emergencies, see Hazcard E as well as more detailed information which may be on this Hazcard.
© CLEAPSS 2009