ELECTROSTATIC DISCHARGE (ESD)
We are all familiar with the naturally occurring static electricity, associated with thunderstorms which is caused by the friction of air molecules in the upper atmosphere, an action which results in often quite spectacular lightning displays. These occurrences are a vital atmospheric interaction which is essential to the survival of all species of life on this earth.
charge accumulation, generated
either naturally in the atmosphere or by man
made technology, can be destructive
when upon discharge, a
resulting spark may ignite
volatile liquids or gases, causing
fire or explosion. Control of electrostatic discharge (ESD) is essential in
these circumstances. ESD can be
described as the action of the
transfer of accumulated
electrostatic charges, which remain
inert on the surface of an object
until contact is made with another
conductive or semi-conductive object, even a human being. ESD can produce
a visible spark.
IN THE HOME AND WORKPLACE
electrostatic charges are also generated artificially
by photocopiers, air conditioning, computers in the office and by
appliances such as hair dryers, dishwashers, washing machines and
A newspaper columnist was
literally thrown from his chair by
the shock as he switched on the computer in his office .The cause?
Electrostatic discharge (ESD)
of the considerable magnitude of
which had accumulated on his body mass as a result of
the synthetic clothing
he was wearing and the
office furnishings. ESD has the
potential to cause malfunction of some
computers when these charges are
transferred from the hand of the operator to the
PC. ( Sydney Morning Herald
elderly lady was reported to have received an electrostatic shock while
using a landline telephone, then became
hypersensitive to all electrical
appliances. In another instance
after replacing several phones for a lady an Australian
telephone company was unable to provide a telephone handset
that was impervious to
ESD. The problem was found to be the customer’s unusually
high rate of ESD
which was severe enough to
cause the phone to malfunctioned.
The phone company solved the problem by providing
her with an anti static table mat. Many
minor incidents of a similar nature have been reported.
People also report being
often painfully ‘zapped’ on touching the metal supermarket trolley or
the car door on leaving the vehicle.
synthetic materials, are known to generate electrostatic charges. Many people
are familiar with the spark and 'ZAP' or mini shock produced by the
electrostatic discharge (ESD) which
occurs at the touch as we
leave a motor vehicle, or on
removing synthetic clothing, combing or brushing hair with nylon comb/brush or
even on touching another person. These
effects are more prevalent in cold or hot, low humidity atmospheric conditions.
Electro static charges produced
under these circumstances may be ignored by some individuals, no more than a
nuisance to others but for the hypersensitive individual, it can be a source of
varying degree of stress. Calibrated instruments are used by industry to
determine the magnitude of electrostatic charges.
WHERE ESD CONTROL IS NECESSARY :
In the hospital
operating theatre synthetic fabrics are banned as they
could generate static sparks.
Where explosives are
used, the operator of the detonator must be 'earthed' so that he does not
accidentally trigger the detonating device with the static charges that his body may carry.
anti-static solutions are sprayed on machine benches and cutting trenches in
clothing factories to prevent
static 'cling' from synthetic fabrics during manufacture
process workers in the electronics industry must use static control
methods in order to prevent static charges transferring to the delicate
electronic components and causing malfunction of the product. Guarantee of
product reliability could
not be given otherwise.
To prevent electrostatic accumulation which
creates a risk of explosion or
fire, motor vehicles
liquids are ‘grounded’ by an
attached metal chain dragging from
the rear of the vehicle, which touches the road at all times.
Somewhat less dangerous is the packaging
of goods where handling of plastic bags can produce considerable static charges on the body mass of the packer. This has been
observed to hinder work
performance. Static control
has been found to improve work efficiency in
It is reported that most Mazda new model cars, have a small anti-static panel
near the inside door handle - this
panel is earthed and requires a light touch to comfortably discharge static from
the body. Anti-static
attached to the rear of a car have been found to benefit
both driver and passengers and to reduce
stress from drivers
though 'sensitivity' may not be evident.
adequate electrostatic discharge (ESD)
control is essential in many
industries. This paper will
illustrate how ESD control has been
found to benefit many people
comfort, better work
performance and well-being .
JUST A PARTY TRICK
ON MOOD AND
Most of us have seen
the paper and nylon comb ‘party trick’ which is one
way to demonstrate static
electricity. Removing synthetic
clothing or brushing hair with a nylon comb/brush, in a darkened room
a visual electrostatic ‘display’
than we might expect,
is the degree of involvement
of ESD in
our lives Most
people are unaware that static electricity is
generated by the friction of the synthetic upholstery fabrics
in motor vehicles, furniture and
soled footwear scuffing against synthetic
floor coverings. Friction of all
synthetic materials, is
known to generate electrostatic charges.
Many of us
are familiar with the 'ZAP' or mini
shock produced by the electrostatic discharge (ESD) of charges we have
accumulated on our body mass. This
can occur as we
touch any conductive or
semi-conductive object, the
metal as we
leave a motor vehicle, or
even upon touching another person. These
effects are more often observed in cold, hot
and low humidity atmospheric
conditions. ESD occurring under
these circumstances may be ignored by some individuals, no more than a nuisance
to others, but for the hypersensitive individual, it can be a source of moderate
to severe stress. In atmospheric
conditions that generate natural electrostatics, school children become
overactive and less easy to control according to teachers.
This same effect may well occur when children are in an environment where
artificially generated electrostatic charges are present, in
large shopping complexes and other air-conditioned
premises, for instance.
attention though is paid to the physical and psychological discomfort of the unfortunate individual who is adversely
affected by the accumulation of electrostatic charges and
by electrostress in general. Reported
effects are moderate to severe
debilitation, clumsiness, memory
lapses, behaviour problems and various
degrees of discomfort, stress and pain.
The ‘sick building syndrome’ list of symptoms is almost identical.
In response to many queries from
people who were seeking relief from the stress levels induced by
our modern indoor
environment, now saturated with electric and magnetic and electrostatic
emissions and charges, advice
was sought from the ESD industry with some success.
On observing electrostatic control -
that is ‘grounding /earthing’ the
person and using other methods of
reducing static build-up, stress
levels were found to be significantly reduced
STATIC ELECTRICITY AND EFFECTS ON HEALTH
electricity produced by electrical equipment and friction of synthetic
furnishing fabrics, is very much evident in our modern homes, offices and in
motor vehicles. An increasing
number of people are developing a hyper-sensitivity to excessive exposure to
these artificially generated fields
of electrical energy. The condition, becoming known as ELECTROSTRESS or
ElectroHyper-Sensitivity (EHS) can develop due to chronic exposure to this
individual can react adversely to any frequency in the electromagnetic
spectrum, including static electricity, experiencing
stress which translates to a
variety of symptoms ranging from
moderate to severe in intensity. Some
reported effects are:
muscle weakness, draining of energy, excessive fatigue.
* clumsiness, person becoming accident prone
* memory lapses
* behaviour problem
found from experience and
observation that very dry skin
and hair adds to the individual
susceptibility to EHS and ESD stress.
known of, or documented on the effects of electrostatics on the human system and
symptoms are often attributed to other factors.
Anecdotal evidence from EHS people, working and living in an artificial
electrical atmosphere, suggests that it may be a problem of considerable
proportions. The ‘sick building’ syndrome
is a modern phenomenon. In
Sweden and UK there are studies underway to determine the extent and cause of
noting is the reported case of a child’s health improving
after electrostatic control was employed in the bedroom.
Initially, magnetic and
electric fields were eliminated from his room, yet some physical symptoms
lingered. The laminated surface of
the bedroom furniture was found to hold a large electrostatic charge, which
transferred to the body mass of the child.
The furniture was treated with an anti-static solution and the
child recovered completely.
people are not aware that static electricity is also generated by the friction
of synthetic fabrics in clothing and
upholstery in motor vehicles
and by synthetic soled footwear against floor coverings.
ESD CONTROL FOR PERSONAL COMFORT
employed in an industry where ESD
control is used may be considered fortunate as he/she is also protected
from the physical effects that ESD
while seeking assistance for means
of relieving stress from exposure
to electric and magnetic field exposure, the
author was alerted to the electrostatic effect and resulting stress.
By means of
ESD control, in the form of the grounded/earthed
anti-static mat or wrist strap, the
considerable stress experienced
from sources of
charge was reduced to
a tolerable level. Since that
time, electrostatic control
has lessened the
discomfort of many people,
especially those who are
electrically hyper-sensitive (EHS). This grounding
method can be used in many
situations to relieve or to prevent electrostress.
is a sample of the empirical
evidence supplied by people who have
derived benefit from observing
control of electrostatic accumulation and electrostatic discharge (ESD).
The original signed letters are on file.
Increased energy levels and
general well-being are some
benefits reported by people who
have avoided electrostatic build-up
or to control often painful
electrostatic discharge (ESD) from
the body mass. ESD occurs on body
contact with another conductive or semi-conductive object as explained earlier..
ESD control has greatly
reduced or completely eliminated
previously experienced stressful symptoms.
Controlling the ESD can be achieved by using a
suitably earthed /grounded antistatic wrist strap or table mat.
reported symptoms and benefits of ESD control:
· Tired and gritty eyes
are no longer a problem
· Operating a sewing
now less stressful, energy levels increased
· A woman with
Electro Hyper-Sensitivity (EHS)
can now tolerate the
dentist’s surgery, where the
electrically operated chair and
fluorescent lights were formerly a problem.
She takes an anti static table MAT
with her on each visit.
· Operating a computer is now less
stressful - work performance
· Induced Repetitive
Strain Injury (RSI ) symptoms which occurred within approximately 45 minutes at the computer –
have been eliminated
· Touching the MAT while
using the telephone has
lessened stress. Electro static charges
and electric and magnetic field emissions from
causes stress for some people. People have found they could use the phone
for the first time in a number of years after observing
· Irritability lessened, better sleep and work performance
using the MAT in the house where considerable
accumulate. The house is situated adjacent to an electricity substation.
computer use -
a grounded, (earthed )
glass shield for the
computer monitor screen is also
advised. This will eliminate 90% of
the electric field emissions from the monitor screen.
HOW THE MAT WORKS.
materials or plastics generally, can
be turned into “semiconductors” by adding certain compounds.
These materials are not quite conductors and not quite insulators.
They have the ability to drain electrostatic discharge (ESD) at a slower
rate than conductors so reducing the possibility of spark.
We call these materials “static dissipative”.
functions as a ‘grounding’ device, eliminating the electrostatic charges
which accumulate on the body mass in certain atmospheric conditions.
MAT is a dissipative material which, upon skin contact allows the ESD
to take place via the attached grounding lead,
in a controlled manner. Incorporated
in the grounding lead, as a safety
factor, is a 1 MegaOhm electrical
resister. The MAT is connected to
the earth pin only of the grounding lead. The
integrity of the grounding system of the building is extremely important and
should be checked by an electrician.
resistivity of the P.V.C. material can be scientifically determined. It falls into the range of 10 9 OHMS
per square (nom). (Ref: USA and
European Ranges for Description of Materials.
EIA – IS5A 1985)
ANTI-STATIC MAT is placed partially under the keyboard of a computer or electric
typewriter, allowing a section
exposed for hand contact with the MAT. Developing
a routine of frequently touching the MAT will allow accumulated static to be
discharged harmlessly to ground, via the earthing system of the electricity
supply. The MAT does NOT use any electricity.
It can be located to be used while ironing, using electric typewriters,
the telephone and computers. Discharging
static by touching the MAT in these
circumstances is found to reduce electrostress.
Anti static wrist straps work well also but are not as convenient as the
The following tips are useful:
natural fibre clothing ,
a perfume free skin moisturizer
a hair product to prevent dry hair.
an anti static solution to wipe
desk and bench surfaces This is
available from hosiery counters and
the same solution on spectacle lenses
HOUSEHOLD ELECTRICAL EARTHING (GROUNDING)
dwellings, as electrical safety standards require, the household water supply
pipe has always been used as the means of 'earthing' the household electrical
supply by bonding the earth wire to the galvanised or copper water pipe.
Due to the more recent practice of using PVC piping for plumbing systems,
electricity safety standards now require the mandatory practice of the
installation of a 1.5 metre copper electrode, at the site of the electricity
meter and for it to be exposed to the weather.
The effectiveness of
any static control device is dependant on the integrity of the earthing/grounding system
of the building. Therefore it is
recommended that the soil surrounding the copper electrode should be kept damp at all
the terrain may be poorly conductive and in very dry weather can be less
effective than desired. Though the
electrode will be installed to electrical safety standard requirements,
empirical evidence indicates that the moisture content of the
surrounding area is essential for
HYPERSENSITIVITY = An unusual or excessive physical or behavioural response to
electric, magnetic emissions and
electrostatic charges. The effect can occur immediately or as a delayed reaction
producing either a debilitating or
hyperactive condition, followed
by period of debilitation as well as a range of physical and psychological symptoms in the
ESD = Electrostatic Discharge