
1 

(1) These Regulations may be cited as the 
Explosives Act 1875 etc. (Metrication and Miscellaneous Amendment) Regulations
1984 and shall come into operation on 8th May
1984.
(2) In these Regulations 
“the principal instruments” means 
— 
(a) the 
Explosives Act 1875,

(b) the Order in Council (No. 16B)
under the Explosives Act 1875,
amending Order in Council of October 26 1896 (No. 16), relating to the keeping
of Mixed Explosives on Registered Premises (“Order
in Council No. 16B”),

(c) the 
Packing of Explosive for Conveyance Rules 1949,


(d) the 
Ammonium Nitrate Mixtures Exemption Order 1967,
and

(e) the Orders in Council and orders
specified in column 1 of Schedule 1
to these Regulations.
2 
The provisions of the principal instruments specified in 
Schedule 1 to these Regulations in column 1
shall be amended by substituting for the measurements set out opposite thereto
in column 3, the measurements set out in the corresponding entry in column
4.
3 
Wherever in either—
(a) 
Articles (1) to (3) of Order in Council No.
16B which specify the maximum quantity of explosive allowed to be kept on
premises registered for the keeping of mixed explosives; or
(b) the Schedule to the 
Packing of Explosive for Conveyance Rules 1949
which specifies the methods of packing authorised explosives;
there appears any imperial measurement of weight or distance
which is specified in Schedule 2
to these Regulations in column 1, there shall be substituted the metric measurement
specified in the corresponding entry in column 2.
4 
The Order of the Secretary of State (No. 11), dated September 20
1924, making Byelaws as to the Conveyance of Explosives on Roads and in certain
special cases shall be amended
as follows—
(a) in regulation
(m) of byelaw 4
(which provides for approval by the Secretary of State of conditions for the
conveyance of explosive in certain carriages and boats) by substituting for
the words “the Secretary of State” the words 
“the Health and Safety Executive”;
(b) in regulation
(p) of byelaw 4
by substituting for the measurement “8,000 lbs.” (which measurement is the maximum amount of explosive to
be conveyed in an enclosed carriage otherwise than on a private railway) the
measurement “5 tonnes.”
5 
Article 2 of the 
Ammonium Nitrate Mixtures Exemption Order 1967
(which article describes a test by which an explosive is to be a prescribed
explosive for the purposes of section 50
of the Explosives Act 1875)
shall be amended by substituting for the measurements—
(a) “12 inches (304.8 millimetres)”
 the measurement “300 millimetres”;
(b) “3 inches (76.2 millimetres)”
 the measurement “75 millimetres”;
(c) “one gramme”
the measurement “1 gram”.
6 
Where any premises or plant in existence or under construction
immediately before the coming into operation of these Regulations complied
with the requirements of the principal instruments as then in force, those
premises or that plant shall be deemed to comply with the principal instruments
as amended by these Regulations.
7 
The Explosives
(Conveyance) (Private Railways) Byelaws 1960
are hereby revoked.
Signed by order of the Secretary of State.
John Selwyn Gummer
Minister of State
Department of Employment
3rd April 1984
SCHEDULE 1
Regulation 2



1 2 3 4
Provisions to be amended Subject-matter of measurement Present measurement 
Substituted measurement
EXPLOSIVES ACT 1875
Parts I
, II and 
III
Section 5:
(proviso (1))
 Maximum amount of gunpowder to which
the section does not apply, if kept for private use and not for sale thirty pounds 
15 kilograms

Section 7 
Area for service of notice on local and harbour authorities one mile 1.6 kilometres


Section 16(3) 
Maximum amount of gunpowder to be kept in certain stores two tons 2,000 kilograms


Section 17: General 
Rule No. (5) 
Amount of gunpowder below which stores need not have a lightning conductor
 one thousand pounds 500 kilograms
Section 22:
General Rule No. (2)(a) Maximum amount of gunpowder allowed in certain registered
premises two hundred pounds 100 kilograms
Section 22:
General Rule No. (2)(b) Maximum amount of gunpowder allowed in other registered
premises— fifty pounds 25 kilograms
 but if in fire-proof safe one hundred pounds 50 kilograms


Section 22: General 
Rule No. (5) 
Amount above which gunpowder shall be kept in a substantial receptacle one pound 
500 grams

Section 24 
Designated area deemed to be part of a building twenty yards 20 metres
 
Additional quantity of gunpowder allowed in a factory under certain conditions
 ten hundred weight 500 kilograms
Section 32 Amount above which gunpowder shall
be sold in a substantial receptacle 
one pound 500 grams
Section
46: regulation
(1) Maximum
amount of gunpowder allowed in cartridge filling room five pounds 2 kilograms


Section 47: regulation
(1) Maximum
amount of gunpowder allowed in certain workshops one hundred pounds 50 kilograms


Section 48: paragraph
(a) Maximum
amount of explosive allowed in small firework factory one hundred pounds 
50 kilograms

Section 48: paragraph
(b) Maximum
amount of manufactured fireworks allowed in small firework factory five hundred pounds 
250 kilograms

Section 48: paragraph
(c) Maximum
amount of coloured fires or stars allowed in small firework factory twenty-five pounds 
12 kilograms

Section 63 
Amount of gunpowder above which a related accident is notifiable in certain
cases half a ton 500 kilograms

First Schedule: 
Part One
Regulation
(1) Maximum quantity of gunpowder allowed under mill stones
in certain circumstances at one time fifty pounds 25 kilograms

sixty pounds
 30 kilograms
Regulation
(2) Maximum
quantity of gunpowder allowed to under press at one time ten hundred weight 
500 kilograms

Regulation (3) 
Maximum quantity of gunpowder allowed to be granulated at one time twelve hundred weight 600 kilograms
Regulation (4) Maximum quantity of gunpowder allowed to be dried
at one time fifty hundred weight 2,500 kilograms
Regulation (5) Minimum distance between press houses etc. and expense
magazines forty yards 35 metres
Regulation (6) Minimum distance between mill and factory magazine
 one hundred and forty yards
 125 metres
Regulation
(7) Minimum
distance for charcoal from a mill, press or magazine 20 yards 20 metres
First Schedule
: Part Two

Regulation (2) 
Maximum amount of gunpowder allowed in a well constructed store four thousand pounds 2,000 kilograms
 Maximum amount of gunpowder allowed in other stores
 three hundred pounds 150 kilograms
Regulation (3) Amount of gunpowder in certain stores three hundred pounds 150 kilograms
 Distance within which store shall be from mine,
quarry, etc. two hundred yards 180 metres
 Minimum distance from house
of store two hundred yards 180 metres
Regulation (5) Amount of gunpowder in certain stores
 three hundred pounds 150 kilograms
 Distance within which store
shall be from mine, quarry etc. two hundred
yards 180 metres
 Minimum
distance from house of store two hundred
yards 180 metres
Regulation
(6) Minimum
distance from the City of London or Westminster of store three miles 5 kilometres

 Minimum distance from borough or market town of store one mile 1.6
kilometres
 Minimum distance from Royal residence of store two miles 
3 kilometres
 Minimum distance from Crown magazine of store two miles 
3 kilometres
 Minimum distance from parish church of store half a mile 
800 metres

Order in Council (No. 1) Classifying Explosives
Class 7 (proviso) Maximum quantity of coloured fire composition in
deemed “manufactured firework” one pound 500 grams


Order in Council (No. 3) relating to Magazines for Explosives other than Gunpowder,
whether with or without Gunpowder

Part II 
Maximum amount of gunpowder allowed in cartridge filling room (all references)
 5 lbs. 
2 kilograms
 Maximum amount of other explosive allowed in cartridge filling
room 5 lbs. 2 kilograms
Part III Maximum amount of gunpowder allowed in workshop
(all references) 100 lbs. 50 kilograms
 Maximum amount of other explosive
allowed in workshop 100 lbs. 50 kilograms
Order in Council
(No. 4) relating to Small Firework Factories
Part II
Preamble: 
paragraph 3 
Maximum amount of gunpowder to be kept in stores two tons 2,000 kilograms

Article 4 
Minimum distance of danger building from other buildings 25 yards 25 metres

Provisos to 
Article 4 
Reduced distance for screened and protected building 12 yards 12 metres
 
Exception for certain magazines 25 yards
 25 metres
Article 6
 Distance,
greater than which, a factory of Division A shall be from—
 
works of Class 1 25 yards 25 metres
 works of Class 2 50 yards 50
metres
 works of Class 3 ¼
mile 400 metres
 Royal residences
 ½ mile 800 metres
 Distance, greater than which, a factory of Division
B shall be from—
 works of Class 1 
50 yards 50 metres
 works of
Class 2 100 yards 100 metres
 works of Class 3 
½ mile 800 metres
 
Royal residences 1 mile 1.6 kilometres
Article 7 Maximum quantities in a factory of Division A of—

 explosives 50 lbs. 25 kilograms
 coloured fires or stars 25 lbs. 12
kilograms
 manufactured fireworks 
150 lbs. 75 kilograms
 Maximum
quantities in a factory of Division B of—
 explosives 100 lbs. 50
kilograms
 coloured fires or stars 
25 lbs. 12 kilograms
 manufactured
fireworks 500 lbs. 250 kilograms

Part III
General Rule No. 6 Minimum distance between fire and danger building
 25 yards 25 metres
 Reduced distance for screened and protected building
 12 yards 12 metres

General Rule No. 20 Maximum quantities in a danger building of—

 explosives 25 lbs. 12 kilograms
 manufactured fireworks 50 lbs. 25
kilograms
 manufactured fireworks during packing 100 lbs. 50 kilograms


Order in Council (No. 6) relating to Stores Licensed for Mixed Explosives


Part I
Preamble: paragraph 3
 Maximum
amount of gunpowder to be kept in stores 
two tons 2,000 kilograms

Article 3(2)(a) Distance in excess of which store of Division A shall be from—

 works of Class 1 75 feet 23 metres
 works of Class 2 85 feet 26
metres

Article 3(2)(b) Distance in excess of which store of Division B shall be from—

 works of Class 1 75 feet 23 metres
 works of Class 2 130 feet 40
metres

Article 3(2)(c) Distance in excess of which store of Division C shall be from—

 works of Class 1 146 feet
 45 metres
 works of Class
2 292 feet 89 metres

Article 3(2)(d) Distance in excess of which store of Division D shall be from—

 works of Class 1 230 feet
 70 metres
 works of Class
2 460 feet 140 metres

Article 3(2)(e) Distance in excess of which store of Division E shall be from—

 works of Class 1 352 feet
 110 metres
 works of Class
2 704 feet 215 metres

Proviso (i) to Article 3(2) Exempted workshops not regarded as protected works—

 maximum quantity of explosive 
100 lb. 50 kilograms
 distance
in excess of which the workshop is from store etc. 75 feet 23 metres

Proviso (ii) to Article 3(2) Railways not regarded as protected works—

 minimum distance from store 
75 feet 23 metres
 distance
within which locomotive is from store 
150 feet 46 metres
Proviso
(iii) to Article 3(2) Minimum thickness of earth mound screening store
 3 feet 
1 metres

Article 3(4) 
Maximum quantity permitted in Division A store—
 (a) general
explosive 150 lb. 75 kilograms
 (b) certain ammunition 700 lb. 320 kilograms

Article 3(5) 
Maximum quantity permitted in Division B store—
 (a) general
explosive 300 lb. 150 kilograms
 (b) certain ammunition 4,000 lb. 1,800 kilograms


Article 3(6) 
Maximum quantity permitted in Division C store—
 (a) general
explosive 1,000 lb. 450 kilograms
 (b) certain ammunition 20,000 lb. 9,000 kilograms


Article 3(7) Maximum quantity permitted in Division D store—
 
(a) general explosive 2,000 lb. 900 kilograms
 (b) certain ammunition 20,000 lb. 
9,000 kilograms

Article 3(8) 
Maximum quantity permitted in Division E store—
 (a) general
explosive 4,000 lb. 1,800 kilograms
 (b) certain ammunition 20,000 lb. 9,000 kilograms


Article 3(9) 
Ratio of reduction in quantity of general explosive to pound kilogram
 
permitted additional quantity of fireworks 
4 lb. 4 kilograms
Article
5 Distance
between store and workshop 75 feet 25 metres

Part III 
Maximum amount of gunpowder allowed in cartridge filling room (all references)
 5 lbs. 
2 kilograms
 Maximum amount of other explosive allowed in cartridge filling
room 5 lbs. 2 kilograms
Part IV Maximum amount of gunpowder allowed in workshop
(all references) 100 lbs. 50 kilograms
 Maximum amount of other explosive
allowed in workshop 100 lb. 50 kilograms
Order in Council
(No. 9) relating to the Sale of Explosive
Preamble Amount above which
gunpowder must be sold in a substantial receptacle 1 lb. 500 grams

Article 1 
Maximum amount of other explosive which may be sold if not in a substantial
receptacle 1 lb. 500 grams
Proviso (a) to 
Article 1 
Maximum amount of gunpowder etc. in an amount of explosive of Class 6 Division
1 which may be sold if not in a substantial receptacle 5 lbs. 2 kilograms


Proviso (b) to Article 1 Maximum amount of explosive of Class 7 Division
2 which may be sold if not in a substantial receptacle 5 lbs. 2 kilograms


Order in Council (No. 11) respecting Notice to be given of Accidents connected
with the Conveyance of Explosives other than Gunpowder Amount of gunpowder above which a related accident is notifiable
in certain cases half a ton 500 kilograms
Amount of other explosive above which a related accident is notifiable
in certain cases 200 lbs. 100 kilograms
Order in Council (No. 12 to replace No.
8) relating to the Keeping of Explosive for Private Use and not for Sale
Preamble Maximum
amount of gunpowder for private use 
30 lbs. 15 kilograms
Article
(2)(a) 
Maximum amount of gunpowder in small arms cartridges to which exception applies
 five pounds 2 kilograms
Article (2)(c) Maximum amount of fireworks to which exception applies
in certain cases five pounds 2 kilograms
Article (3)(a) Maximum amount of explosive which may be specified
in certificate ten pounds 5 kilograms
Schedule Maximum
amount of explosive specified in certificate 
ten pounds 5 kilograms
Order in Council (No.
16) repealing and consolidating the previous Orders relating to Premises registered
for Mixed Explosives
Part I
General 
Rule No. 2(5) 
Amount above which certain explosives must be kept in closed bag or case 1 lb. 500 grams

 Amount of certain explosives above which packages may not be opened
on registered premises 1 lb. 500 grams
 Maximum amount of certain
explosives which a package opened for immediate use may contain 5 lbs. 2 kilograms


Part IV 
Maximum amount of gunpowder in cartridge filling room (all references) 5 lbs. 2 kilograms

 Maximum amount of small-arm nitro-compound in cartridge filling
room 5 lbs. 2 kilograms
Order in Council (No. 16A) varying the Order in Council (No.
16) of October 26 1896, relating to Premises registered for Mixed Explosives

Preamble Maximum
quantity of fireworks, Mode A 200 lbs.
 100 kilograms
 Maximum quantity
of fireworks, Mode B 50 lbs. 25 kilograms
Article 1 Maximum weight for “Shop Goods” Mines,
Jack-in-the-boxes and Feu de Joie 2 lbs.
 1 kilogram
 Maximum weight
for “Shop Goods” Maroons 
4 ozs. 100 grams
 Maximum
length for “Shop Goods” Chinese Crackers 4 inches 100 millimetres

Article 2 
Ratio of “Shop Goods” to 
two pounds (2 lbs.) 2 kilograms
 
manufactured fireworks one pound (1 lb.)
 1 kilogram
Order in Council (No. 26) relating
to Picric Acid, Picrates and Mixtures of Picric Acid with other Substances

Article 2(b)
 Maximum
quantity of picric acid not deemed to be an explosive 1 lb. 500 grams
Order in Council
(No. 27) (The 
Explosives (Di-nitro-phenol and Di-nitro-phenolate) Order 1927)
Article 2(c) Maximum quantity of di-nitro-phenol to which the
Order does not apply 5 lb. 2 kilograms
Order in Council (No. 28) (The Sale of Explosives Order 1928)
Article 3 Amount of explosive which must be exceeded in a
certificate of a Chief Officer of Police 
ten pounds 5 kilograms
Order in Council (No.
30) prohibiting the Manufacture, Importation, Keeping, Conveyance or Sale
of Acetylene when an Explosive as defined by the Order

First provision Pressure above which
acetylene is deemed to be an explosive 
nine pounds to the square inch 620 millibars


Proviso (1)(a) Maximum pressure of acetylene used in the production
of organic compounds {three hundred pounds
per square inch 21 bars
{twenty-two pounds per square
inch 1.5 bars
Proviso (1)(b)
 Maximum
pressure of acetylene in any other case 
twenty-two pounds to the square inch 
1.5 bars

Order of Secretary of State (No. 5), dated March 28 1898, relating to Compressed
Acetylene in Admixture with Oil-Gas Maximum pressure at which acetylene
in admixture with oil-gas is deemed not to be an explosive one hundred and fifty pounds to the square
inch 10 bars
Order of Secretary of State
(No. 5A), dated September 29 1905, relating to Compressed Acetylene in Admixture
with Oil-Gas
Condition 4 Maximum pressure at which acetylene in admixture with oil-gas
is deemed not to be an explosive 
one hundred and fifty pounds per square inch 
10 bars

Order of Secretary of State (No. 9), dated June 23 1919, relating to Compressed
Acetylene contained in a Porous Substance
Condition (6) Maximum pressure in a cylinder of acetylene two hundred and twenty-five pounds to the square
inch 15.5 bars
Related temperature sixty degrees Fahrenheit 15 degrees Celsius
Proviso to condition (6) 
Volume of certain cylinders one cubic
foot 30 litres
 Maximum pressure
to which such cylinders may be charged one hundred and fifty pounds to the square inch 10 bars
 Related temperature 
sixty degrees Fahrenheit 15 degrees Celsius

Condition (7)
 Volume of certain cylinders one cubic foot 
30 litres
 Maximum pressure allowed in such cylinders two hundred and twenty-five pounds to the square inch 15.5 bars
Condition (11) Volume of cylinders
required to have certain markings one
cubic foot 30 litres
Order of Secretary of
State (No. 11), dated September 20 1924), making Byelaws as to the Conveyance
of Explosives on Roads and in certain special cases

Byelaw 1 Amount below which explosive may be conveyed in
a passenger-carrying carriage or boat 
5 lbs. 2 kilograms
Byelaw
2: paragraph (a)
 of the proviso Minimum space between case and outer package of detonators three inches 
75 millimetres

Byelaw 2: paragraph
(b) of the proviso Minimum thickness of soft material for outer packages of electric
detonators half an inch 13 millimetres
Byelaw 4 Quantity of certain explosives above which byelaw
applies 5 lbs. 2 kilograms
Byelaw 4; 
regulation (k) 
Maximum quantity of explosive which may be carried with flammables etc. 50 lbs. 25
kilograms

Byelaw 4; regulation
(l) Quantity
of explosive above which delay in conveyance is not allowed 100 lbs. 50 kilograms


Byelaw 4: regulation
(m) Quantity
of explosive above which precautions must be taken against the introduction
of fire-producing objects etc. 100 lbs.
 50 kilograms
Byelaw 4
: regulation (n)
 Quantity
of explosive above which personnel must be acquainted with byelaws 100 lbs. 50
kilograms

Byelaw 4: regulation
(o) Quantity
of explosive which when exceeded during conveyance in towns and villages must
be attended by a competent person 100
lbs. 50 kilograms
 Quantity
of explosive which when exceeded elsewhere must be attended by a competent
person 1,000 lbs. 500 kilograms
Byelaw 4: 
regulation (p) 
Maximum quantity of explosive to be conveyed in a carriage or boat with unprotected
stowage 2,000 lbs. 1 tonne
 Maximum quantity of explosive to be conveyed on
a private railway in an enclosed carriage 
16,000 lbs. 8 tonnes
 Maximum quantity of explosive to be conveyed in
any one boat with a close deck 50,000
lbs. 25 tonnes
 Maximum calibre
of quick firing ammunition 3-inch 77 millimetres
 Limit that may be exceeded
by non-communicating explosives 2,000
lbs. 1 tonne
 Maximum quantity
of non-communicating explosives allowed in one carriage 10,000 lbs. 5 tonnes


Byelaw 4: regulation
(q) Minimum
distance between carriages or boats containing explosive 50 yards 50 metres


The Control of
Explosives Order 1953
Schedule Quantity of gunpowder specified in licence and the endorsement
thereon pounds kilograms
 Quantity of safety-fuze specified in licence and
the endorsement thereon pounds kilograms
The 
Keeping of Fireworks Order 1959
Article
3(2) 
Quantity of fireworks kept in Mode B above which a closed metal container
shall be used one hundred pounds 50 kilograms
 Maximum quantity of fireworks
to be kept in any one container one hundred
pounds 50 kilograms
Schedule 
Maximum quantity of “Shop Goods”—Mode A 2,000 lbs. 1,000 kilograms

 Maximum quantity of explosive of Class 6 Division 1—Mode
A 500 lbs. 250 kilograms
 Maximum quantity of “Shop Goods”—Mode
B 500 lbs. 250 kilograms
 Maximum quantity of explosive of Class 6 Division
1—Mode B 500 lbs. 250 kilograms
 Maximum quantity of explosives in room to which
the public have access etc. 100 lbs.
 50 kilograms
SCHEDULE 2
Regulation 3


1 2
Present measurement 
Substituted measurement
1 lb./pound 500 grams
2 lb./two pounds 1 kilogram

5 lb. 2 kilograms
15 lb(s). 
7 kilograms
20 lb. 10 kilograms
25 lb. 12 kilograms
50 lb(s). 25 kilograms
60
lbs. 30 kilograms
100 lb. 
50 kilograms
120 lb. 60 kilograms
200 lb(s). 100 kilograms
500 lbs. 
250 kilograms
0.5 inch 13 millimetres
3 inches 75 millimetres