Risk Assessment of low voltage

products

Jon Ivar Tidemann

Vice President Nemko Group

What is «Risk assessment»

Incidents

Design

knowledge

Harm

Use

Accidents

RISKReduce below

Tolerable level

• Cenelec Guide 29 , Temperature of hot surfaces likely to

be touched.

• Cenelec Guide 14, Child Safety

• ISO/IEC 71 Addressing needs of elderly and people with

disablitites

• Commission Decision 2010/15/EU Guideliens for RAPEX

and How to perform Risk Assessment for Market

Authorities

• Ares(624717) EU general risk assessment methodology

• LVD ADCO 14-10 Identification of Child Appealing

products

• Cenelec Guide 32

How to find helping docs?

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• LVD Directive 2014/35/EU, Annex III,2.The technical documentation shall include an adequate analysis and assessment

of the risk(s).

The Blue Guide gives further information.Essential requirements must be applied as a function of the hazard inherent to a given

product.

Therefore, manufacturers have to carry out risk analysis and determine the essential

requirement applicable to the product.

This analysis has to be documented and included in the technical documentation, unless

risk assessment is included in the harmonized standard. In addition, the manufacturer

needs to document the assessment of how he is addressing the risks identified to ensure

that the product complies with the applicable essential requirements (for example, by

applying harmonised standards). If only part of the harmonised standard is applied or it

does not cover all applicable essential requirements, then the way applicable essential

requirements not covered by it are dealt with, should be documented

Reference to the Blue Guide is to latest version July 2016.

Mandatory risk analysis from April 20th, 2016

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Description by EU of compliance process for

CE-marking directives

.

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• Gives « Presumption of Conformity »

• Does not replace legally binding essential requirements.

• Manufacturer always, even when using harmonized

standards, remains fully responsible for assessing all the

risks of his product in order to determine which essential

(or other) requirements are applicable

• After this assessment a manufacturer may then choose to

apply specifications given in harmonized standards to

implement “risk reduction measures”

Use of Harmonized standards

Blue Guide 4.1.2.2

• Harm

• physical injury or damage to persons, property, and domestic animals Note 1 to

entry: Physical injury or damage to persons also includes health aspects.

• Hazard

• potential source of harm

• Hazard zone

• any space within and/or around LV equipment in which persons, or domestic animals

can be exposed to a hazard

• Hazardous event

• event that can cause harm

• Hazardous situation

• circumstances in which persons, property and domestic animals or the environment

are exposed to at least one hazard

• Incident

• past hazardous event

Definitions

• intended use

• use of LV equipment in accordance with the information for use provided by

the supplier

• malfunction

• situation for which the electrical equipment does not perform the intended

function due to a variety of reasons

• reasonably foreseeable misuse

• use of LV equipment in a way not intended by the designer, but which may

result from readily predictable human behavior

• residual risk

• risk remaining after protective measures have been taken

Definition

• Risk

• combination of the probability of occurrence of harm and the severity of

that harm

• tolerable risk

• risk which is accepted in a given context based on the current values of

society

• risk assessment

• overall process comprising a risk analysis and a risk evaluation

• Safety

• freedom from unacceptable risk

Definition

• Minimum necessary risk reduction:

the reduction in risk that has to be achieved to meet the

tolerable risk for a specific situation

• The tolerable risk will depend on many factors

• severity of injury,

• the damage to property,

• the number of people exposed to danger,

• the frequency at which a person or people are exposed to

danger

• duration of the exposure

Basic Priciples of Safety Integration

Principle of Safety Integration

Step Examples

1. Does not

have

2 Surface

covered

3 Warning

in user

guide

Danger for touching hot surface

• Example from EMC,

What is tolerable risk

0

5

10

15

20

25

30

35

40

45

50

30M 50 60 80 100M 200 300 400 500 800 1G

Le

vel in

dB

µV

/m

Frequency in Hz

EN 55022 B 10m QP

Unacceptable

Better

Perfect

Tolerable

Use of product or other parametres could lead to other levels

of tolerable risk.

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Difference between risk analyses and

assessment

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Process as described by European Market Authorities.

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• some elements to consider when describing the product

Describing the product

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What is Child appealing

Also consider child appealing situations

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• Split between intended Use (I) and missue or not intended

use (NI)

User/Consumer

Vulnerable groups

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Other aspect related to the consumer/user

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• Electric shock

• Heat

• Fire

• Low power High Voltage

Electrical dangers

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• Weight

• Surface

• Crush Hazard

•

Mechanical dangers

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• X-ray

• Lasers

• Radio / electrical field

Radiation dangers

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• Toxic

• Corrosive

• Environmental danger

Chemical substances

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• Safe products can be unsafe in some situations

The human factor

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• Your remote.

• Your door.

• Not your neighbors.

Performance

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• Largest risk - human behavior

Risk analyses

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• Largest risk - human behavior

Risk analyses

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• Largest risk - human behavior

Risk analyses

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Not “just” a theoretical exercise

• Even if the safety standard is fulfilled – what may happen?

• Conventional bulb into fixture

designed for LED?

Risk analyses

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Not “just” a theoretical exercise

• Even if the safety standard is fulfilled – what may happen?

• Indoor equipment

used outdoor?

Risk analyses

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Most injury scenarios consist of the following three main

steps:

• The product has a “defect” or can lead to a “dangerous

situation” in its lifetime.

• The “dangerous situation” leads to an accident

• The accident results in an injury

Where the product displays several hazards/ injuries, risk

scenarios should be developed for each. If one injury can

lead to another- then combined.

Injury scenario: steps leading to injury(ies)

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• Child is taking the cat-figured lamp into bed causing burn

• Child is taking the cat-figured lamp into bed causing a fire

• Child is breaking lamp exposing live parts and is

electrocuted

• Elderly electrocuted from heating mattress after many

years use of the mattress caused by destroyed wires

Some examples

Risk Estimation

• 1) one person or the equipment itself or property in the

next environment;

• 2) several persons or damage in wider environment (e.g.

affects a whole building or more)

If more than one person can be expected to be injured or

killed the conclusion of harm is frequent-to-continuous

and/or exposure time is long

Extent of harm

• Both normal conditions as well as single fault conditions

shall be taken into account.

• Simultaneous occurrence of two independent and

unrelated faults are not taken into account, unless:

a) a second fault is a consequence of the first fault

• b)a double fault situation with two independent and

unrelated faults where the first fault situation is not

automatically detected.

Probability of occurrence of harm

• need for access to the hazard zone (e.g. for normal

operation, correction of malfunction, maintenance or

repair);

• nature of access (e.g. manual operation of the equipment

or automatic operation )

• time spent in the hazard zone;

• number of persons requiring access;

• frequency of access;

• protection already in place

Exposure to hazardous situation

• a) by whom the LV equipment is operated:

– by skilled persons;

– by unskilled persons

– unmanned

• b) the human ability to avoid or limit harm (e.g. reflex,

agility, possible escape):

– possible;

– possible under certain conditions;

– impossible

Ability to limit harm

• c) any awareness of risk:

– by general information;

– by direct observation;

– through warning signs and indicating devices

• d) by practical experience and knowledge:

– of the LV equipment;

– of similar LV equipment;

– no experience

Ability to limit harm

• e) how quickly the hazardous situation leads to harm:

– suddenly;

– fast;

– slow

• f) the range of susceptibility to harm of the different

exposed persons and the extent to which the harm can be

reduced

Ability to limit harm

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• The probability of injury is the probability that injury

scenario may materialize during the expected lifetime of

the product.

• It is normally generated by multiplying the probability of

each step leading up to the overall probability of the

scenario

Probability of Injury

• Probability to be devided into 8 levels:

• Example: handle of cup breaking causing burs from hot

liquid

• - Handle to break of: 1/1000 (example only)

- Cup in position to spill: 1/2 (example only)

- Fluid hot enough to cause burns: 1/10 (example only)

• Probability will then be: 1/1 000 * 1/2 * 1/10 = 1/20 000

which will be in group 1/100 000

Calculating the risk index

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The severity of the injury reflects the effect the hazard has on the

consumer under the condition described in the injury scenario.

The severity is divided into 4 categories:

• Injury or consequence that after basic treatment (first aid, normally not by a doctor)

does not substantially hamper functioning or cause excessive pain; usually the

consequences are completely reversible.

• Injury or consequence for which a visit to A&E may be necessary, but in general,

hospitalization is not required. Functioning may be affected for a limited period, not

more than about 6 months, and recovery is more or less complete.

• Injury or consequence that normally requires hospitalization and will affect functioning

for more than 6 months or lead to a permanent loss of function.

• Injury or consequence that is or could be fatal, including brain death; consequences

that affect reproduction or offspring; severe loss of limbs and/or function, leading to

more than approximately 10 % of disability.

Severity of injury

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Severity of injury-Examples:

Type of injury Severity of injury

1 2 3 4

body in eye Temporary pain in

eye without need

for treatment

Temporary loss of

sight

Partial loss of sight

Permanent loss of sight

(one eye)

Permanent loss of

sight (both eyes)

Hearing injury,

foreign body in ear

Temporary pain in

ear without need

for treatment

Temporary

impairment of

hearing

Partial loss of hearing

Complete loss of

hearing (one ear)

Complete loss of

hearing (both

ears)

Poisoning from

substances

(ingestion,

inhalation, dermal)

Diarrhoea,

vomiting, local

symptoms

Reversible

damage to

internal organs,

e.g. liver, kidney,

slight haemolytic

anaemia

Irreversible damage to

internal organs, e.g.

oesophagus, stomach,

liver, kidney, haemolytic

anaemia, reversible

damage to nerve

system

Irreversible

damage to nerve

system

Fatality

Concussion — Very short

unconsciousness

(minutes)

Prolonged

unconsciousness

Coma

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• The probability of injury is the probability that injury

scenario may materialize during the expected lifetime of

the product.

• It is normally generated by multiplying the probability of

each step leading up to the overall probability of the

scenario

Probability of Injury

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• It is normally generated by multiplying the probability of

each step leading up to the overall probability of the

scenario

Possible way of calculating

Where:

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When all risks are addressed and calculated

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The 2 ways to compliance

Define intended use

and foreseablemissue

Identify Hazards

Estimate risks

Check all risks

covered

Identify essential

requirements

Document in TCF

Identify covering

harmonized

standards

Document in TCF

Full risk assessment,

reduction, mitigation

Risk analyzes

Found Not Found

Route 1 Route 2

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Check box Date

Risk analyzes completed √ 13.11.2015

Essential requirements identified √ 13.11.2015

Harmonized standards:

- scope of the standard fully covers the product/all parts of the

product

- use of the product and the user and user location is in line with

the standard

- standards used are harmonized and currently valid according to

OJ ( Official Journal of EU)

√

√

√

13.11.2015

13.11.2015

13.11.2015

The product is evaluated not to have any risks outside what is

covered in listed safety standards. √ 13.11.2015

No further evaluation is deemed necessary √ 13.11.2015

Added into technical file √ 13.11.2015

Appointed responsible for keeping risk analyzes, modifications of

product / standards and TCF updated√ 13.11.2015

Route 1- Harmonized standards cover

Verify

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• Several helping documents available from ISO, IEC and

Cenelec.

• EU commission to make their own for reporting of

hazardous products on the EU Market.

• EU Commission via DG SANCO have made web based

templates and electronic reporting in RAPEX.

• DG SANCO is perforing training of member states Market

Authorities.

Route 2-Full Risk Assessment

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Are the risks tolerable, or-

• Trainig of users necessary

• Re-design needed

• Additional information in user instructions

If everything is satisfactory then into TCF.

Remember to re-visit if changes to product,

standards/legislation, feedback from Market.

Final -

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• Nanomaterials require a risk assessment.

• Chemical hazards shall normally be conducted according

to ECHA guidance

• Machinery and Medical have own standards for risk

assessment.

Special risk assessments required for some

materials / products.

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Example

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• Assumptions:

• It is a child of age 1-3 in 5% of homes having an iron

• User of the iron is away for some seconds in 1% of

situations.

• Child try to raise and catch the iron in 10% of situations

What is the risk for this to happen?

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• Iron need to tilt and fall down-50% probability

• What happens then?

• Hit in the head

• Falls down and brakes so child can get electrical shock

• Falls down on the body of the child

• Does not brake and child take it up to iron on body

• Falls down and scares the child to run away

Sequence for accident to happen

If child grips cord-then 50%

PROBABILITY TO BE HIT!

Otherwise approx 25%

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Overall probability and severity

Probability:

1/20 x 1/10 x 1/100 x 1/2 x 1/2 = 1/ 80 000

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Result –Low risk

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Questions?

Jon Ivar Tidemann

Nemko Group

Vice President Energy & Environment

TEL +47 22 96 04 55

MOB +47 950 72469

FAX +47 22 96 05 50

EMAIL jonivar.tidemann@nemko.com

Thank you