What is the Importance of a

Halogen-free Printed Circuit

Board?

During the development of printed circuit boards, there are

many compounds and elements that are utilized for a

variety of purposes. During the early days of PCB

development, many toxic compounds were used as either a

cost-saving aspect of manufacturing or because of the

specific, helpful nature of the element. As humanity

develops an increased understanding of the threats that past

materials present to life in today’s world, manufacturers

are changing methods and finding new materials that don’t

pose a threat to individuals working with such creations.

Common compounds that are used in PCB developments

belong to the family of Halogen elements. Although the

composition themselves provide certain benefits to the

development of electronics, they are harmful to human life

in one way or another.

During the development of printed circuit boards, there are

many compounds and elements that are utilized for a

variety of purposes. During the early days of PCB

development, many toxic compounds were used as either a

cost-saving aspect of manufacturing or because of the

specific, helpful nature of the element. As humanity

develops an increased understanding of the threats that past

materials present to life in today’s world, manufacturers

are changing methods and finding new materials that don’t

pose a threat to individuals working with such creations.

These elements are:

- Fluorine

- Chlorine

- Bromine

- Iodine

- Astatine

While there is still debate on the toxicity of halogens

within PCB development, there are two primary elements

that constitute the general consensus of a halogen-free

circuit board. These two are chlorine and bromine. Each

provides a specific benefit to the overall safety and

functionality of electronics but pose a threat to the

continuity of life for humans and nature.

Functionality of Chlorine

The element chlorine is used in a wide array of products. It

is a prime ingredient used in bleaches for cleaning as well

as sterilizing pools to kill off bacteria. In small and diluted

doses, this element can help in the protection of life from

illnesses developed by virus and bacterial strains.

However, dangerous concentrations of chlorine can pose

certain health risks.

Some of the symptoms of chlorine exposure include:

- Blurred vision

- Uncontrollable coughing

- Severe skin irritations and pain

- Nausea- Difficulty breathing

- Burning sensation in nose, throat and the eyes

Continued exposure to chlorine can cause severe

complications such as pulmonary edema, or consistent

fluid in the lungs. According to a study published in a

previous edition of Pediatrics, children are eight times

more likely to develop asthma while swimming in Chlorine

treated pools as opposed to not. The effects of chlorine

including the disposal and destruction of related products

are prompting the Restriction of Hazardous Substances

directive to consider placing chlorine on the list for

electronic compliance. Not only is it a threat to human life,

but it is a toxic element that can cause severe damage to an

eco-system.

How is Chlorine Used in Electronics?

Generally, there are many uses for chlorine-based

components when developing electronics. Although the

element was initially an effective tool for development, the

threat it poses can be difficult to bypass.

Some of the uses of this material include:

- Polyvinyl Chloride coatings for cables and wires

- Chlorinated flame retardants to protect components and

devices

- Trichloroethylene solvents used in semiconductor

development

- Trichloroethane solvents to clean computer chips

Functionality of Bromine

Although bromine doesn’t have the notoriety and

popularity with household products as its companion, it is

still used in a variety of ways that many people may not

consider. It, too, is used in water treatment for swimming

pools and hot tubs as well as controlling bacterial growth

and algae within industrial processes. It is used in the

agricultural industry as a pesticide. Bromine is also being

tested for use in batteries for electric vehicles.

Coincidentally, bromine is also a component of many

pharmaceuticals in the health industry.

However, high concentrations of bromine can cause:

- Nausea

- Watery eyes

- Skin irritations and burns

- Headaches and dizziness

Sustained exposure to bromine can cause brain damage as

well as kidney failure due to systemic poisoning. The

blood pressure of an individual could drop to intolerable

levels for internal organs, assisting in overall physical

dysfunction. For those that continuously breathe in

bromine, there is an increased chance of long-term lung

problems of varying degrees.

How is Bromine Used in Electronics?

Currently, many brominated compounds are restricted by

the RoHS directive. Primarily, these chemical

compositions serve to act as flame retardants generally

used in plastics for the chassis of electronic devices as well

as on the PCB itself. Although it serves the purpose of

protecting against further damage from the onset of a fire,

it’s still a dangerous component to work with especially

when inhaled as fumes from a melting plastic chassis.

According to PCI-SIG, the special interest group

responsible for universally specifying Peripheral

Component Interconnect buses for computer systems, the

printed circuit motherboard constitutes the largest

contribution of weight from halogen materials. In light of

the weight distribution of this component, it is imperative

for IT support staff to consider safe methods for disposing

of upgraded motherboards in computer systems.

Environmental Impact of Chlorine and Bromine

The importance of halogen-free components can be viewed

as an effect of the aftermath from disposal of various

electronics. While merely handling a PCB will more than

likely not affect an individual, it is the incineration and

destruction of components that pose the more serious

threat. Dioxin is a compound that forms when chlorine-

based components are brunt with the addition of

hydrocarbons. According to the United States

Environmental Protection Agency, dioxin is one of the

most toxic chemicals currently known to exist.

Dioxin has been confirmed by the EPA to cause cancer

within humans. This means that incineration of PCBs

developed with chlorine-based products has a strong

likelihood to cause fatal injuries to individuals simply

breathing in the fumes produced. In January of 2001,

dioxin was upgraded to be a known human carcinogen. A

couple of years later, it was determined that there is no

known tolerance level or safe dosage that will not

ultimately cause cancer. A study completed in 2012 has

reassessed the dangers of dioxin which have been found to

be within the tissues of animals that humans consume.

The toxicity that is created from improper disposal could

put individuals and eco-systems in great jeopardy. Precious

metals aside, choosing a halogen-free product can keep

your developers and future technicians safer from

experiencing health complications due to exposure. Show

your responsibility to the environment and prevent these

toxic compounds from interacting with nature in a negative

way.

PCB Solutions provides high-quality printed circuit boards

to meet a variety of needs in the dynamic electronics

industry. We are a PCB manufacturer that support domestic

and off-shore prototyping to provide low, medium and high

volume production. If you are looking for a flexible PCB

manufacturer, PCB solutions is the right option.