Michel Brochier

Ruddy Branka

EU DIRECTIVE ON THE PLACING ON THE MARKET OF PYROTECHNIC ARTICLES Elements to deal with the Essential Safety Requirements for Fireworks

The Directive 2007/23/EC of the European Parliament and of the Council on the placing on the market of pyrotechnic articles has been adopted by the European Union (EU) on the 23rd of May, 2007. This Directive should help manufacturers and importers that had to comply with a different regulation in each country to get technical approvals of their pyrotechnic articles. Although this directive will reduce the administrative burden for everybody by introducing the CE marking and certification procedure, its substitution and application instead of the current national regulations may create difficulties in the beginning.

In this paper we present information related to the different parts of the Directive dealing specifically with fireworks ; taking into account the present French regulation and European standards on fireworks, we remind and comment topics like categorisation, labelling, testing methods for fireworks characterisation and requirements for safety levels ; these elements are reviewed and commented in the scope to help people concerned to comply with the Essential Safety Requirements (ESR) of the new Directive.

SCOPE OF THE DIRECTIVE

• free movement of pyrotechnic articles (including fireworks), while ensuring public security, safety of consumers and environmental protection.

• replacing some 27 parallel national approval procedures by one single EU directive • reduction in costs for the industries concerned, and ensures that essential safety requirements for pyrotechnic articles are respected throughout the EU.

DEFINITIONS

• Fireworks : pyrotechnic article intended for entertainment purposes • Pyrotechnic article : article containing explosive substances or an explosive mixture of substances designed to produce heat, light, sound, gas or smoke or a combination of such effects through self-sustained exothermic chemical reactions.

• Person with specialist knowledge : person authorised by a Member State to handle and/or use category 4 fireworks

TIME SCHEDULE

Entry into force : This Directive has entered into force on the 20th day following its publication in the Official Journal of the European Union, i.e. 4 July 2007.

Transposition : Member States shall adopt and publish, by 4 January 2010, the laws, regulations and administrative provisions necessary to comply with this Directive. They shall forthwith communicate to the Commission the text of those provisions. They shall apply those provisions by 4 July 2010 for fireworks of categories 1, 2 and 3 by 4 July 2013 for other pyrotechnic articles, for fireworks of category 4 and for theatrical pyrotechnic articles.

CONFORMITY ASSESSMENT PROCEDURES

Possible procedures allowed by the Directive are : a) "module B" (EC type-examination procedure) and "module C" (conformity to type procedure) or "module D" (production quality assurance procedure) or "module E" (product quality assurance procedure) or b) "module G" (Unit verification procedure) or c) "module H" (Full product quality assurance procedure)

3/14 CATEGORISATION OF FIREWORKS Directive : Fireworks shall be categorised as follows :

Category For use only by people over 18 years old and with specialist knowledge (i) the safety distance must be at least 1 m. (ii) the maximum noise level must not exceed 120 dB (A, imp), at the safety distance, (iii) category 1 must not comprise bangers, banger batteries, flash bangers and flash banger batteries, (iv) throwdowns must not contain more than 2,5 mg silver fulminate.

(i) the safety distance must be at least 8 m. (ii) the maximum noise level must not exceed 120 dB (A, imp), at the safety distance.

(i) the safety distance must be at least 15 m. (ii) the maximum noise level must not exceed 120 dB (A, imp), at the safety distance.

No explicit requirement on safety distance and noise. 1. Manufacturers shall ensure that fireworks are properly labelled visibly, legibly and indelibly in the official language(s) of the Member State in which the article is sold to the consumer. If the firework does not provide sufficient space for the labelling requirements, the information shall be provided on the smallest piece of packaging.

2. The labelling of fireworks shall include as a minimum a) the name and address of the manufacturer or, where the manufacturer is not established in the Community, the name of the manufacturer and the name and address of the importer b) the name and type of the firework, c) the minimum age limits, d) the relevant category e) instructions for use, f) the net equivalent quantity (NEQ) of active explosive material and g), depending of the category, : Category 1 Category 2 Category 3 Category 4 where appropriate: "for outdoor use only" and minimum safety distance.

"for outdoor use only" and, where appropriate, minimum safety distance(s). the year of production, "for outdoor use only" and minimum safety distance(s). the year of production "for use only by persons with specialist knowledge" and minimum safety distance(s).

French regulation (Art. 12 Decree nr 90-897 dated October the 1st, 1990)

The labelling of fireworks shall include :a) generic designation of the fireworks, b) commercial designation, c) category, d) "shall be used conforming to the regulation related to public safety and environment protection", e) French approval number, f) name and address of the responsible of the first putting on the market and g), depending of the category, : Category 1 Category 2 Category 3 Category 4 (*) Precautions for safe use of the firework "sale forbidden to people under 18 years old -Use shall conform to the recommendations sheet" "sale forbidden to people under 18 years old -Use shall conform to instructions for use (**)" "sale forbidden to people under 18 years old -Sale and use shall conform to provisions of articles nr 12 to 16 of the decree nr 90-897 dated October the 1st, 1990, related to fireworks regulation" "fireworks to be used only by holders of qualification K4 licence, or under the control of such a person. "firing exclusively with electrical igniter" (*) for fireworks category "K4 ARP" one additional red label shall be stuck on the firework with the mentions :"Fireworks with enhanced hazards", "This fireworks shall be processed (installation, implementation, and firing…) only by a holder of the K4 qualification licence himself" and "safety distance shall be strictly applied" (**) (much more detailed document than recommendations sheet) 6/14

ESSENTIAL SAFETY REQUIREMENTS

In the first following paragraph, we present a review of existing known methods used or intended to be used for checking the safety of fireworks ; in the second paragraph, we make a proposal of how these methods can help to check the essential safety requirements of fireworks to be certified. Although the following documents involve complete electric detonators, they may be helpful to issue methods for electrical characterisation of igniters for fireworks, as required in the ESR of the Directive; indeed, electric igniters used for fireworks are mainly of the same type than electric fusehead used in detonators for mines and quarries, and their connection to the firing line and "blasting machine" is made quite in a similar way.

Essential safety requirements

Existing methods that may contribute to comply with the ESRs (1) Each firework must attain the performance characteristics specified by the manufacturer to the notified body in order to ensure maximum safety and reliability.

N1, CEN 10, 11

(2) Each firework must be designed and manufactured in such a way that it can be disposed of safely by a suitable process with minimum effect on the environment.

CEN 7, A11 Note (a) (continued) Existing methods that may contribute to comply with the ESRs (3) Each firework must function correctly when used for its intended purpose. Each pyrotechnic article must be tested under realistic conditions. If this is not possible in a laboratory, the tests must be carried out in the conditions in which the fireworks are to be used.

N1, CEN 11

The following information and properties -where applicable -must be considered or tested: E2, CEN 20 (e) Resistance of the pyrotechnic article to moisture where it is intended to be used in humid or wet conditions and where its safety or reliability may be adversely affected by moisture ;

No method at present

(f) Resistance to low and high temperatures, where the pyrotechnic article is intended to be kept or used at such temperatures and its safety or reliability may be adversely affected by cooling or heating of a component or of the fireworks as a whole ;

No method at present (g) Safety features intended to prevent untimely or inadvertent initiation or ignition ; L4, CEN 2, 3, 22 (h) Suitable instructions and, where necessary, markings in respect of safe handling, storage, use (including safety distances) and disposal in the official language or languages of the recipient Member State ; See § 7 Note (a) (i)The ability of the pyrotechnic article, its wrapping or other components to withstand deterioration under normal, foreseeable storage conditions ; E2, I6, J7, CEN 20, 21 (j)Specification of all devices and accessories needed and operating instructions for safe functioning of the pyrotechnic article.

(a)

During transportation and normal handling, unless specified by the manufacturer's instructions, the fireworks should contain the pyrotechnic composition.

I6, J7, CEN 8

(4) fireworks must not contain : (a) commercial blasting agents, except for black powder or flash composition ;

(b) military explosives.

Note (b) CEN 7 A11

11/14

Essential safety requirements (continued) Existing methods The ignition devices (fuse and electric fusehead are used for fireworks) must at least also comply with the following requirements:

(1) Ignition devices must be capable of being reliably initiated and be of sufficient initiation capability all normal, foreseeable conditions of use.

See below (6), (7)

No method at present for initiation capability

(2) Ignition devices must be protected against electrostatic discharge under normal, foreseeable conditions of storage and use.

(c)

(3) Electric igniters must be protected against electromagnetic fields under normal, foreseeable conditions of storage and use.

(c)

(4) The covering of fuses must be of adequate mechanical strength and adequately protect the explosive filling when exposed to normal, foreseeable mechanical stress.

CEN 1, 2

(5) The parameters for the burning times of fuses must be provided with the article.

CEN 4 (7) The wires of electric igniters must be sufficiently insulated and must be of sufficient mechanical strength, including the solidity of the link to the igniter, taking account of their intended use. (a) Instructions, including disposal, to be given to the user in a document "instructions for use" or equivalent (b) Mandatory information to be given by the manufacturer or importer in his technical file when applying for CE certification (c) For that purpose, electric sensitivity of electric igniters is limited in France (firing current must be over 200 mA)

CONCLUSION

The Commission has given a mandate to CEN to prepare harmonised standards to support the new Directive.

Although the scope of the Directive is broader than the current scope of CEN/TC 212, this Technical Committee has been designated to carry out the standardisation work.

The title of CEN/TC 212 was "Fireworks" and its current scope was "Standardisation of ready-for-use pyrotechnic articles (= consumer fireworks) for entertainment purposes, particularly from the point of view of their safe use".

Its new foreseen title will be "Pyrotechnic articles" and its new scope "Standardisation of pyrotechnic articles, in accordance with the Essential Safety Requirements from the Pyrotechnic Articles Directive, particularly from the point of view of the protection and safety of consumers" Concerning Fireworks, the mandate given to CEN/TC 212 is • to draw up a fireworks standard containing a list of articles which fall under category 1 without any doubt, a list of articles which do not fall under category 1, as well as a procedure/guideline/criteria which determines which article falls in category 1,

• to adapt the existing standards accordingly,

• to review the existing standards in order to accommodate possible category 4 fireworks,

• to develop new category 4 firework standards. We hope the information collected and presented in this paper will help to clarify the context in some minds and contribute to the future European standardisation work.

  (a) Cal ≤ 300 mm or NEQ <≤ 10 kg for "K4 ARP" NL1 : at 2,38 m (b) Cal ≤ 210 mm or Cal ≤ 100 mm and ahead ignition or NEQ < 7 kg for "K4 ARP" NL2 : at 8 m (c) Cal ≤ 100 mm or NEQ < 150 g for "K4 ARP" NL3 : at 15 m (d) NEQ ≤ 6 kg and Cal from 40 to 100 mm or angular battery with α >30° for "K4 ARP" NEQ : Net Equivalent Quantity (of active explosive (e) Nautical shell, aerial wheel, ground shell with flash composition >45 g and < 70 g for "K4 ARP"

  (a) Design, construction and characteristic properties, including detailed chemical composition (mass and percentage of substances used) and dimensions ; The physical and chemical stability of the fireworks in all normal, foreseeable environmental conditions ; Sensitivity to normal, foreseeable handling and transportation ; I6, J7, CEN 21, (d) Compatibility of all components as regards their chemical stability ;

  For information : Initial proposal for categorisation from the European Standardisation Technical Committee 212 "Fireworks" (see ref.(4)) :

	Categorisation issued from the current French regulation (Art. 12 Decree nr 90-897 dated October the 1st, 1990) :
		Category 1		Category 2		Category 3	Category 4
		Fireworks which present a	Fireworks which can be used	Fireworks which can be used	Fireworks which can be
		very low hazard		as they are sold, without		as they are sold, without	assembled and used only by
				hazard for the user if he takes	hazard for the user if he takes	holders of the qualification
				into account simple		into account procedures given	K4 licence, or under the
				precautions described in a	in the document "instructions	control of such a person.
				recommendation sheet.		for use".	Category 4 "ARP" (*) see
						notes (a) to (e)
		No general restriction on	For use only by people over	For use only by people over	For use only by people over
		minimum age		18 years old		18 years old	18 years old and titular of a
	Spherical shell : Cylindrical shell : Shell / flash composition :	forbidden forbidden forbidden		Cal ≤ 65 mm NEQ <≤ 100 g Cal ≤ 65 mm NEQ <≤ 100 g forbidden	Cal ≤ 105 mm NEQ <≤ 500 g Cal ≤ 105 mm NEQ <≤ 500 g NEQ < 45g	qualification K4 licence Cal ≤ 200 mm (a) Cal ≤ 125 mm (b) Cal ≤ 65 mm or NEQ < 100g
	Bangers : Bangers battery : Battery and combination : Roman candles : Other fireworks :	NEQ < 3 g or NL1 < 161 dB 50 max bangers NL1<157dB NEQ < 10 g NEQ < 10 g NEQ < 10 g	NEQ < 10 g or NL1< 163 dB 500 bangers max NL2<154dB NEQ ≤ 100 g NEQ ≤ 100 g NEQ ≤ 100 g	Not applicable NEQ ≤ 500 g NL3 < 151 dB NEQ ≤ 500 g NEQ ≤ 500 g NEQ ≤ 500 g	Not applicable Not applicable NEQ ≤ 6 kg and Cal ≤ 40 mm (c) Cal ≤ 75 mm (d) Not applicable (e)
	(*) In France : fireworks "Category 4 ARP" are fireworks category 4 with enhanced hazard ; these fireworks can be assembled and used only by the holder of
	the qualification K4 licence himself)				NL : Noise Level in dB (lin, peak)
	Category 1		Category 2	Category 3	Category 4
	Fireworks which present a very low hazard and	Fireworks which present a low	Fireworks which present a	Fireworks which present a high
	which are intended for use in confined areas,	hazard and which are intended for	medium hazard and which are	hazard and which are intended for
	including fireworks which are intended for use	outdoor use in confined areas	intended for outdoor use in	use by persons with specialist
	inside domestic buildings				large, open areas	knowledge
				4/14

1.2 Documents issued by the CEN TC 212 Technical Committee 31

  European standards corresponding to 31 fireworks from categories 1 to 3 have been published by the Technical Committee CEN TC 212 (see annex 1). For each product, these "product" standards give testing procedures. The scope of these procedures and their typical associated requirements are reminded in the table hereafter :

	Ref. CEN 25 Attachment of friction head For information, only used for Bengal matches Safety item Typical requirements (continued)
	CEN 3 CEN 26 Performance test Initial fuse ignition	The fuse shall ignite before 10 s ; the ignition shall be For information, differs for the various fireworks
	CEN 27 Length of handle	visible For information, only used for hand-held fountains
	CEN 4 CEN 28 Length of hand-held sparkler For information, only used for hand-held sparklers Duration of initial fuse Time to ignition of the first effect of the firework shall be 3 s
	to 13 s depending of the firework category CEN 29 Attachment of separate handle For information, only used for hand-held fountains
	CEN 5 CEN 30 Droop test Determination of net	Maximum mass stated, depending on the category and type For information, only used for hand-held sparklers
	7.1 CEN 31 Length of pull string explosive content EXISTING TESTING METHODS of the firework For information, only used for party-poppers CEN 6 Mass of report charge Maximum mass is stated, depending on the composition : CEN 32 Protection of throwdowns For information, only used for throwdowns
	black powder, nitrate/metal based or perchlorate/metal based 8.1.1 Testing methods from the French approval procedures and regulation composition
	Ref (*) Title CEN 7 Chemical compositions A11 Description L4 Ignition duration N1 Functioning J7 Drop test E2 Thermal stability I6 vibrations N2 Formation of projected debris N3 Projection scale N4 Effect in altitude N5 Noise CEN 15 Sound pressure level CEN 14 Integrity in flight of the pyrotechnic unit height of explosion / bursting Description List of excluded products, a) for safety reasons, b) for testing point and at a height of 1 m above the ground) Measurement of the noise of the fireworks. (ex : 120 dB (A,imp) at a horizontal distance at 15 m from checking of the effect Maximum level stated, depending on the firework category For fireworks functioning in altitude, measurements of altitude and wheels..) Measurements of the distance of projections from small fireworks No loose parts before the final effect (rockets, aerial projection. For category 1 fireworks, checking that there is no harmful firework 50 Hz, 60 min. } CEN 13 Means of monitoring the Higher than 20 m ; depending on category and type of The integrity of the fireworks is checked after vibrations { 0.5 mm, ex : of mortar, of shell… 60 RH } conditioning CEN 12 Material Generally cardboard, wood, paper, plastics (non-metallic) ; The integrity of the fireworks is checked after a { 50°C, 3 days, CEN 11 Functioning The firework shall function completely The integrity of the fireworks after drop (1.2 m) is checked CEN 10 Principal effect The effect shall conform to the expected and described one recommendations from the instructions for use functioning as well as the conformity to the expected effect and the 10° to the horizontal ; they shall not neither fall over when The correct and complete functioning of the fireworks is checked not fall over when they are placed on a surface inclined at is measured CEN 9 Vertical stability For fireworks designed to be placed on the floor, they shall Time between ignition of the fuse and the first pyrotechnic output pyrotechnic composition loose analysis if required) CEN 8 Material integrity No hole or split in the case of the firework that may lead to The pyrotechnic article is described (dimensions, mass, chemical toxicity reasons, see annex 2 8.1.3
	CEN 16 Burning matter	Maximum distance from the test point is stated for no
		burning or incandescent matter falling to the ground ;
		depends on the firework category
	CEN 17 Angle of ascent	+/-15° from the vertical axis (rocket or aerial wheel for
		example).
	CEN 18 Projected debris and mass of	Maximum distance from the test point and maximum mass
	debris	are stated for debris falling to the ground ; depending on the
		firework category
	CEN 19 Labelling	Type and name categories, safety information (depending on
		the category), instruction for use, name, address and
		telephone number of the manufacturer, the distributor or the
	Ref. CEN 1 CEN 20 Thermal conditioning Safety item Attachment of protruding fuse Shall withstand 100 g whilst 10s importer, reference to the standard Typical requirements 4 weeks at 50 °C CEN 21 Mechanical conditioning {50 g ; 60 ms ; 25 mm}, 1 Hz, 1 hour CEN 1b Attachment of initiating fuse Shall withstand 100 g whilst 10s CEN 1c Attachment of sealing paper or ignition head CEN 22 Resistance to ignition by an No ignition when striking on an abrasive paper sheet Shall withstand mechanical shock {490 m/s² ; 60 ms ; abrasive surface conforming to ISO 6344-3 25 mm} at 1 Hz during 2 hours CEN 2 Protection of initial fuse CEN.23 Length of uncoated end of Minimum 20 mm length or 40 % total length (for Bengal Cover on fuse or primary pack shall be present, or resistance wooden stick matches) to side ignition shall be proved (see CEN 2b) CEN 2b Side ignition test of initial fuse CEN 24 Determination of the location For information, only used for shell in mortars The protruding fuse shall not ignite when a smouldering of the shell cigarette is placed on the side of the fuse Ref. Safety item Typical requirements (continued)

(*) These methods are described in details in Ref. (

6

) 8.

Standards issued by the CEN Technical Committee nr 321 "Explosives for civil use -detonators and relays"

Possible testing methods and procedures to deal with the Essential Safety Requirements :

	Standard Ref.	Title	Description
	EN 13763-17	Determination of no-fire current Maximum current that the electric detonator can
			withstand without firing
	EN 13763-18	Determination of series firing	Current necessary for reliable ignition of electric
		current	detonators connected in series
	EN 13763-19	Determination of firing impulse Electric pulse necessary for reliable ignition of
			electric detonator (for discharge electric
			capacitance based blasting machine)
	EN 13763-20	Determination of total electrical	Information needed for reliable ignition of electric
		resistance	detonator connected in series
	EN 13763-22	Determination of capacitance:,	For safety against electrostatic discharge and
		insulation resistance, and	reliable ignition
		insulation breakdown of leading
		wires
	8.2

  6) The electrical characteristics (e.g. no-fire current, resistance, etc.) of electric igniters must be provided with the article

	EN 13763-
	17, 18, 19,
	20, 22
	See ref. (8)

Essential safety requirements

Essential safety requirements (continued)

Existing methods that may contribute to comply with the ESRs

(5) The fireworks must at least also comply with the following requirements :

(1) The manufacturer must assign fireworks to different categories according to Article 3 characterised by net explosive content, safety distances, noise level, or similar. The category must be clearly indicated on the label.

See § 4

(a) For category 1 fireworks, the following conditions must be met : (i) the safety distance must be at least 1m. However, where appropriate the safety distance may be less, (ii) the maximum level must not exceed 120dB(A,imp), or an equivalent noise level as measured by another appropriate method, at the safety distance, (iii) category 1 must not comprise bangers, banger batteries, flash bangers and flash banger batteries, (iv) throwdowns in category 1 must not contain more than 2,5 mg silver fulminate.

See § 4

(b) For category 2 fireworks, the following conditions must be met : (i) the safety distance must be at least 8 m. However, where appropriate the safety distance may be less, (ii) the maximum noise level must note exceed 120dB(A,imp), or an equivalent noise level as measured by another appropriate method, at the safety distance.

See § 4

(c) For category 3 fireworks, the following conditions must be met : (i) the safety distance must be at least 15 m. However, where appropriate the safety distance may be less, (ii) the maximum noise level must not exceed 120dB(A, imp), or an equivalent noise level as measured by another appropriate method, at the safety distance.

See § 4

(2) Fireworks may only be constructed of materials that minimise risk to health, property and the environment from debris.

Note (b), N1, N2, N3, N4, CEN 9, 10, 11, 12, 14, 16, 17, 18 (3) The method of ignition must be clearly visible or must be indicated by labelling or instructions.

See § 7

(4) Fireworks must not move in an erratic and unforeseeable manner.

Note (b), N1, N2, N3, N4, CEN 9, 10, 11, 12, 14, 16, 17, 18 (5) Fireworks of categories 1, 2 and 3 must be protected against inadvertent ignition either by a protective cover, by the packaging, or by the construction of the article. Fireworks of category 4 must be protected against inadvertent ignition by methods specified by the manufacturer.

ANNEX 2

TC 212 list of chemical substances forbidden for fireworks : -arsenic or arsenic compounds; -mixtures containing a mass fraction of chlorates greater than


C Didier

MRPP: The French Prevention Procedure to Manage Post-Mining Hazards

Even if most French mining sites are definitively closed, potential risks remain above the abandoned exploitations. Those risks influence the land use management of post-mining areas. In order to manage properly those risks, French State has developed a technical and regulatory tool: the MRPP (Mining Risk Prevention Plan). MRPP aims to identify the most sensitive areas subject to "post mining hazards" and to define regulations able to manage future urbanism development on surface. The present paper proposes a methodological description of MRPP in order to explain the nature and objectives of the procedure.

Introduction

Since a few decades, mining industry, which has been during a long period a powerful industrial activity in France, has progressively decreased. Today, most mining sites are closed down but the potential occurrence of hazards and disorders on surface have not definitively disappeared. ln addition to potential ground instability phenomena (subsidence, sinkholes, etc.), some mining sites may be affected by dangerous gas emissions, flooding events or environmental degradations. These effects can occur as soon as the mining extraction stops but also, in certain circumstances, long time after closure. These phenomena may have major consequences for people, activities and property located on surface in the mine surroundings. They are also likely to have a major influence on regional development in mining areas.

In order to evaluate, post and manage properly those hazards and risks, French Authorities have developed a technical and administrative tool: the MRPP (Mining Risk Prevention Plan). Those Plans are intended to identify the sectors most likely to develop risks in the long term and draw up rules for managing land use according to the various post-mining constraints.

The present paper gives a brief account of the principles supporting the drafting of MRPP, with respect to both administrative procedure and technical requirements of risk evaluation. It is illustrated through a few examples of MRPP elaborated by INERIS during the last 5 years.

The MRPP, a tool for risk prevention management

The MRPP in French Risk Prevention Policy

In France, it is the State responsibility to evaluate hazards and risks as well as to be sure that the information is transmitted and available to citizens. Concerning post-mining hazards, French law n° 99-245, of 30 March 1999, set up the Mining Risk Prevention Plans (MRPP).

The main purpose of MRPP is to take risks into account within land-use management [START_REF] Didier | The MRPP: a powerful operational regulatory tool to prevent and manage post-mining risks[END_REF]. MRPP procedure is usually requested in sectors exposed to high levels of risk. However, it can also be implemented, as a preventive measure, within zones which may constitute a risk in future and, therefore, in zones where urban development must be limited to avoid an increase of existing risk level. Thus the MRPP process is mainly focus towards the future, through the idea of "prevention". MRPP identifies zones, which are directly or indirectly exposed to risks, by taking into account the nature and level of risk. Within these zones instructions based on town planning and construction regulations are defined. They have to be applied to each building project, concerning new installations as well as existing properties and activities.

MRPP is a powerful regulatory tool appended to Local Urbanism Plans (established in each French town). It systematically takes priority if the two documents are not fully compatible. There are also many administrative tools assuring the MRPP regulation implementation, starting with penal sanctions in case the rules are not applied.

Administrative procedure for drafting a MRPP

The Prefect, as the Regional State representative, initiates the MRPP procedure via a "prescription order". This order defines the geographical extent covered by the study and the nature of risks involved. The prevention procedure is applied, as far as possible, to global physical units, called "risk basins" defined by natural parameters and/or operations but not by administrative limits (city border, concession limits).

All town councils in the communities geographically concerned are systematically requested to give their opinion during the MRPP elaboration. When the process is finished, the Prefect also submits the draft plan to a public consultation among the populations concerned.

At the end of this consultation the MRPP is approved by a Prefect order. The regulations defined take precedence over the Local Town Planning plans drawn up by town councils.

The main phases of drawing up an MRPP

As shown if figure 2, an MRPP is elaborated in four main stages.

The data collection phase is designed to collect all available information (including further investigations if they are strictly necessary). It requires an on-site investigation and consultation of archives. This phase ends with the production of an information map, which is of first utility for diffusing essential information among the population (figure 1). This map helps to justify the prevention procedure undertaken by summarising the disorder and harmful effect, which have already affected the site in the past.

Figure 1 Example of an information map.

The hazard assessment stage is intended to locate the sectors exposed to potential phenomena according to the magnitude of the predictable events as well as their predisposition to development. A hazard evaluation does not take into account surface occupation. The objective of this stage is the drafting of maps locating hazard zones identified by the assessment process.

The stake assessment stage includes drawing up an inventory of all existing stakes in hazardous areas and identifying the potential future projects, which may develop as a result. It is used to identify the population subjected to a non-zero risk level. In particular, it is required to list the most sensitive equipment or public establishments. It results in the production of a map including all the stakes concerned.

The regulatory zoning phase defines homogeneous zones in terms of prohibitions, obligations or recommendations concerning land use, for both new and existing projects. The principle of this zoning is particularly based on the confrontation between the hazardous levels previously identified and the assessment of existing and future stakes characterising the surface. A set of rules is drawn up which is directly linked to this zoning. It is intended to define, clearly and operationally, the regulatory measures, which apply to each regulatory zone. 3 Identifying, listing and mapping hazards and stakes

Principles for identifying and mapping hazards

Definition

A hazard corresponds to the probability that a given phenomenon will develop on a given site during a reference period, reaching a quantifiable magnitude. Characterising a hazard is therefore usually based on the predictable magnitude of the phenomenon with its probability of occurrence.

The magnitude of the phenomenon corresponds to the amount of disorders or harmful effects likely to result from the feared phenomenon. This notion includes both quantification of the consequences of the feared events (i.e. size of a crater) and the potential severity of their effect on people or goods (possibility of victims or damage, existence and/or cost of prevention measures, etc.).

The probability of occurrence reflects a site's sensitivity to be affected by any of the analysed phenomena. This is a concept, which is particularly difficult to quantify considering the complexity of the triggering mechanisms, the heterogeneity of the rock mass and the very partial information available. Therefore, within the context of post-mining hazard assessment, priority is given to the notion of a site's predisposition to suffer future disorders. Evaluation of this predisposition depends on the combination of several parameters, which are favourable or unfavourable to the initiation and development of the identified mechanisms.

Qualification of magnitude and predisposition classes

The magnitude of the phenomenon characterises the amplitude of the expected consequences if the feared event takes place. Each type of phenomenon has one or more corresponding representative physical values, which can be used to characterise the consequences of the feared events. It is therefore, for example, the size of craters which defines the intensity of sinkholes.

To evaluate the magnitude of the feared phenomena, the expert attempts to evaluate, often approximately, the expected value of the parameter judged to be representative. Regarding to reference values defining the main magnitude classes, the expert can then define the class to which the feared phenomenon belongs within the relevant context. These reference values have been defined in the framework of a methodological guideline dedicated to the MRPP drafting. This was done under the scientific co-ordination of INERIS, a French Public Expertise Body in, charge of assessment of risks related to industrial activity.

The suggested reference values are provided for information and can be adapted to a specific context by the expert in charge of risk assessment. The main interest of this "reference values" step is to contribute to enable a homogeneous approach at a national level. This limits indeed the subjectivity of the analysis inherent to the sensitivity of each expert.

As an example, the following table shows the magnitude classes of the phenomena representative of different classes of disorders. Determining predisposition is first based on an experience feedback analysis taking into account disorders or harmful effects having already affected the site (or a similar site) in the past. The assessment is also based on the analysis of scenarios and mechanisms, which may trigger phenomena likely to affect surface land. For example, a very thick overburden, small-scale residual voids and presence of strong layers in the overburden will make this site less predisposed to sinkholes in comparison with shallow mining works located under a "marly" overburden.

Predisposition assessment is often complicated by lack of information available especially in very old mining works. It may then appear necessary to manage such a lack by using the concept of "presumption".

Hazard assessment principles

The principle of hazard qualification consists of combining criteria used to characterise the intensity of a feared phenomenon with the criteria used to characterise the predisposition class. Several principles, explicit or implicit, can be used to combine qualitative values with quantitative criteria.

Nevertheless it has to be noticed that MRPP has been conceived to evaluate hazard and risk levels, at the state of knowledge and according to the expert judgement. Hazard assessment methods consist thus generally of qualitative approaches based on the available data collected on site or from archives. This choice aims to privilege relatively rapid and not too costly hazard assessment studies. The scope is to make MRPP possible in a reasonable time and cost above the most alarming abandoned mines in the view of public safety.

In terms of assessment methods, when the cross-referenced table principle is selected, a synthesis matrix is used as it is done in table 2. To avoid complicated restitution maps, it is usually suggested to limit, as far as possible, the hazard levels to three classes: low, moderate and high hazard level. Hazard assessment quality is often strongly correlated with the amount and quality of available data. Visits of old underground mining works are usually of first interest to recognise the mining configuration as well as the failure mechanisms affecting the mining structures (figure 3).

LOW HAZARD MODERATE HAZARD HIGH HAZARD

Figure 3 Visit of abandoned underground mining works in iron ore field of Normandy

Unfortunately disused underground mining works are often no longer accessible in safe conditions (mine openings closed, unstable galleries, presence of water and/or gas). The hazard assessment process must thus be operated on the basis of the only available data (old maps, mining reports).

This inevitably results in a certain uncertainty in zoning, which may sometimes be important. This uncertainty margin can, in certain cases, be reduced thanks to the complementary investigations or analyses. Such investigations are to be considered case-by-case, according to the complexity and the danger of the studied phenomena as well as the sensitivity of surface occupation. It is also necessary to evaluate the time requested for these works.

If necessary, some investigations may be undertaken to characterise and/or locate old mining voids (drillings, geophysical methods) in sectors where sensitive stakes are present (cities, infrastructures).

In the same way, the complexity and danger of certain configurations may require to develop numerical models reproducing, as accurately as possible, the rock behaviour. Such analyses were carried out to evaluate the risks associated with a continuous or discontinuous subsidence above major French mining fields: iron ore basins of Lorraine [START_REF] Fougeron | Collapse/subsidence: evolution of the overburden massivity according to the geomorphology in the Lorraine iron mines case[END_REF] and Normandy [START_REF] Renaud | Modeling and assessment for subsidence hazard in declined iron mining[END_REF], coal basin of Provence [START_REF] Didier | Importance of failure mechanisms for management of surface instability risk above abandoned mines. 10th Congress of the ISRM[END_REF].

Hazard mapping

The hazard has to be mapped for the whole sector concerned by the MRPP so as to demonstrate which sectors are most likely to develop risks or harmful effects. A scale of 1/10 000 is often used to reach a satisfactory compromise between MRPP principles (small scale) and communities requirements (large scale).

The hazard zoning contours are based on technical parameters (geology, operation, etc.). They therefore have no reason to follow the contours of the land plots. When, as it is often the case, several potential phenomena coexist on the same plot, the powerful tools of Geographical Information Systems (GIS) are very performing.

Hazard mapping includes surface areas concerned by the possible effects of phenomena resulting from mining activities. It therefore takes into account the possible lateral extension of disorders or nuisances initiated in underground spaces and developing towards the surface. It also includes the uncertainties associated with the available geographical information (figure 4).

Principles of assessing and mapping the stakes involved

Stakes assessment phase

The procedure for assessing stakes involved in mining risks consists of identifying the main types of land occupation or activities, both existing or future, which are likely to interfere with the risk prevention procedure. The major stakes concerned will naturally include urban sectors where the regulatory measures to be applied may differ from those defined for non urbanised sectors.

Assessing all the stakes concerned also includes evaluation of endangered people and listing the main stakes related to safety, crisis management and vital functions in the area. Therefore public establishments, particularly the most strategic in terms of emergency aid organisation (schools, hospital, etc.) are identified.

Sensitive equipment (roads, electricity, gas, phone, etc.) are also listed. Traffic roads which must be secured in priority to facilitate public assistance are of first importance.

Stakes mapping

The stakes map (figure 5) is produced at the scale selected for drawing up the MRPP (often 1/10 000).

Figure 5 Example of a stakes identification map above an undermined town (North of France).

Depending on the different objectives (personal safety, future urban development, etc.), a few maps can be drawn up giving priority to the most concerned stakes.

Drawing up the zoning plan and regulations

Principles for regulatory zoning

Posting hazard and drawing up a regulatory zoning plan are two specific procedures with fundamentally different objectives. Whereas the first identifies the different types of disorder likely to develop on the surface and locates them, the second marks out the limits of the zones where homogeneous instructions can be defined to ensure the safety of existing and future people and property.

The zones are marked out by cross-referencing hazard and stakes maps, i.e. by combining the type and intensity of a predictable disorder with the occupation of surface land. In general, definition of the different zones is based on constructibility criteria (zones where no building is allowed, areas where building is permitted under certain conditions, etc.). As for hazards, the aim is to avoid multiplying the number of zones, to facilitate the legibility of the maps. For this purpose, the number of zones selected must be limited to three or four. One uses generally a white zone for which the requirements are minimal or non-existent, a red one for the sectors where building is forbidden and one or two blue zones in which urbanisation remains possible but with more or less severe constraints and restrictions (figure 6).

Generally speaking, priority will be given to the development of new urban areas in non risky zones. However although this rule can be applied relatively strictly for areas not yet urbanised, constraints may be relaxed locally in urbanised areas with strong constraints due to mining-related risk over a major part of the area occupied by the communities in question. In this case, building permits may be envisaged in low or moderate risk zones. The regulatory zoning plan must be drawn up, as far as possible, at a scale compatible with studies of risk and stakes assessment phases.

Drawing up the regulations

At the same time as the zoning regulations are drawn up, the State Department in charge of drafting the MRPP draws up the regulation which defines the regulatory provisions applied to each zone within the regulatory zoning area. These measures are mainly intended to improve the safety of people and property in the zones subject to mining risks. They prevent increasing vulnerability of property and activities in the most exposed zones.

The regulations must be as simple and operational as possible to make it easier for the public to understand and assimilate them. It is generally presented by the type of regulatory zone (red, blue, white) after defining the general measures applied to all the plots in the limit of the MRPP (figure 6).

Figure 6 Example of a regulatory zoning map above an undermined town (North of France).

For each zone, it is usual to organise the measures in two groups: those dealing with existing properties and those intended for future projects. The different measures may take the form of prohibitions, obligations or simple recommendations.

One has to notice that one of the regulatory specificity of MRPP, which makes this tool powerful, is the retroactivity that is to say, that measures can be applied to an existing property prior to MRPP. However, if there is no restriction for future projects, the measure imposed to the property built prior to MRPP approval can only lead to some limited changes, costing less than 10% of the market value of the property before the risk was posted.

For a successful drafting and application of the MRPP, all available expertise (administrative, technical and political) must be federated. Regular discussions and meetings are therefore requested between the State Departments and local authorities, to facilitate understanding, appropriation and participation of local authorities in the risk prevention policy.

It is therefore essential to obtain the participation of local representatives when drawing up the regulatory zoning plan and regulations because they are the main authorities in charge of application and in direct relation with the population.

5 First experience feedback

Work Progress

Since MRPP creation in 1999, more than forty abandoned mining sites located throughout French territory have been studied on the basis of MRPP procedure (figure 7).

To these sites, one has to add the whole Lorraine iron ore field whose analyse has been initiated before MRPP introduction. For this basin, about a hundred under-mined cities have been analysed producing hazard and risk maps. The MRPPs implemented have concerned the main mining ore exploited in France. One may quote metal mines (lead-zinc of South-Centre and Brittany, copper in the Alps, uranium in Centre-West, etc.), major iron ore fields (Lorraine, Normandy) and many coal basins (Provence and Centre-South…).

The next important step of MRPP implementation will be the major salt basins (Lorraine, Jura, South-West).

The beginning of the studies is planned for 2008.

Until now, the great majority of the studied sites concern the "surface instability" hazard. Among those instabilities, the sinkhole phenomenon is of the first importance. It is related to shallow abandoned mining works (few tens metres deep) as well as the sectors highlighting many mine openings (shafts, adits, etc.).

Although generally less sensitive, hazards related to mine gas emission has also been highlighted in many abandoned mining sites [START_REF] Tauziède | Risk assessment of gas emission at the surface of French abandoned coal mines and prevention techniques[END_REF]. Much more punctually, "environmental hazards" have been identified in some unfavourable contexts mainly resulting from the exploited ore (lead, zinc, silver, etc.).

Experience feedback on MRPP implementation

Since the process initiation in 1999, MRPP contributed to prevent several potential risky situations resulting from post-mining hazards.

In sensitive areas in term of surface occupation (high level of stakes, social pressure for urbanism development) the existence of disused mining works was not sufficient to limit or at least regulate urban development. One of the major advantages of a MRPP is that it makes possible to define rules that lead to organise city expansion. In the areas with low surface occupation, MRPP enables to formalise the knowledge related to the existence of disused mining works, which is often unknown by citizens, especially when the mine was closed down long time ago. MRPP allows thus to update and to synthesise the available data as well as a definition of urbanism rules in the sectors where the location of buildings is possible .

Other experience feedback has resulted from the many investigations performed.

The hazard and risk assessment process is generally restricted to available data at present state of knowledge. This usually induces an over-estimation of the risk level (precaution principle), for example in defining hazard zoning in the areas where mining works are supposed to be present. This conservative approach is not always very easy to understand by local people. It presents however the advantage to define, for future surface developers, the investigations essential to enhance the knowledge on mining works and, thus, on remaining hazards.

The existence of a precise mine closure applications [START_REF] Didier | Closing down and securing underground mining works in France[END_REF] performed by the mining operators enhance considerably the state of knowledge. Hazard and risk evaluation and mapping are then much more precise and reliable, reducing by the way the extension of the sectors where the constraints have been defined only by presumption. Generally, such closure applications are only available for the recent mine abandonment.

The PPRM planning has not always been optimal during the first implementation years. The choice of studied sites was, at first, mainly suggested by regional authorities, depending on the criteria that were not always felt pertinent. "Political pressure" has thus contributed to initiate studies in some areas with a very limited urban development. This has contributed to justify, for about 3 years now, the "Mining Sites Screening Process" [START_REF] Didier | The French Experience of Post Mining Management[END_REF]. This global approach aims to analyse very rapidly about 3000 abandoned mining sites throughout France in order to hierarchise them regarding risk level. The process contributes thus actively to an efficient future MRPP integrating hazard and stakes criteria on the basis of priorities.

Further technical developments requested

Due to the lack of an operational methodology, "environmental hazard assessment" has, up to now, been reduced to strict minimum. Just few cases, with serious problems, have generated environmental hazard maps. Methodological tools and approaches are presently being developed. They will be operational in the coming years. Besides hazard assessment, one may also raise the question of the definition of regulatory principles related to those kinds of hazards.

Finally, the MRPP is definitely a multi-hazard and multi-risk tool (surface instability, gas emission, environmental impacts, flooding event, etc.). Indeed coupling and combining different phenomena is not an easy task concerning hazard identification and characterisation. New scientific knowledge and technical tools are needed in this complex field.

The task appears to be even more complicated concerning transcription of multi-hazard phenomena in terms of regulatory measures. Some classical measures adapted to certain kind of hazard prevention have to be proscribed in case other hazard phenomenon may also develop at the same place. Flooding events and subsidence movements may thus contribute, for example, to prescribe incompatible measures for the design of building foundations.

Figure 2

 2 Figure 2 Simplified diagram of the main stages of a MRPP implementation.

Figure 4

 4 Figure 4 Example of a hazard map in the Lorraine iron ore field (North-East of France)

Figure 7

 7 Figure 7 Location of the abandoned mining sites, where MRPP have been implemented.

hazard map. Stakes assessment stage. Inventory of existing factors and potential future projects Production of a stakes map. Regulatory zoning stage.

	MRPP Prescription order by Prefect.
	Definition of geographical extent &
	identification of nature of risks
	Appointment
	of the Aministrative Service
	and the Expertise Organism in charge
	of the MRPP implementation.
	Data collection stage. Collection of data (on site, archives… ).	Production of an information map .
	Hazard assessment stage.
	Hierarchisation of the hazard level, depending on magnitude and probability of occurrence of the suspected phenomena. Production of a Elaboration of regulations defining Production of a the rules to be applied regulatory zoning map..
	for land-use management.
	Town councils & population
	consultation ..
	Final approval of MRPP by Prefect.
	This takes place after eventual modifications
	resulting of the organised consultations.
	MRPP is appended to
	Local Urbanism Documents.

Table 1 Magnitude classes defined by reference threshold values

 1

		Flooding	Surface instability
	Magnitude classes	Discharge modification (flow rate in dm 3 /s).	Diameter of crater left by sinkholes
	Limited	Seepage (< 1)	Ø < 3 m
	Moderate	Small stream (< 10)	3 m < Ø < 10 m
	High	Large stream	Ø > 10 m

Table 2 Example of hazard assessment method based on cross table (magnitude vs predisposition)

 2

	Predisposition	Very low	Low	Moderate	High
	Magnitude
	Very low
	Low
	Moderate
	High

Acknowledgements

The authors would like to thank warmly the French State and, in particular, the French Ministry in charge of Industry for its technical and financial support for the methodological development and MRPP implementation. They also thank GEODERIS, French Public Expertise Body for its valuable contribution in planning and co-ordinating MRPP implementation in France.