Subject: | |
From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Thu, 10 Feb 2000 10:17:52 -0000 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Paul,Brian,
I also am not a toxicologist, but here's some information I picked
up over
the years. I understand it to be true but...........(disclaimer)
The flame retardent used in most - if not all - standard FR4 is TBBA
(tetra-
bromo bis-phenol A), this works by generating bromine fumes which
deprive the fire of oxygen and therefore make the laminate self
extinguishing.Some bromine flame retardents can produce
dioxins. TBBA is said not to do that.
Bromine is given off when the laminate burns but I'm not sure if
bromine
is given off when the laminate is heated to a certain temperature.
For more information on flame retardents, try these sites:-
http://www.bsef.com
http://www.firesafety.org
For the summary of a study into flame retardsnts try:-
http://www.surrey.ac.uk/PRC/
FR4 laminates are available without bromine, they are called halogen
free laminates and are usually based on phosphorous or
nitrogen compounds.
hope this helps
geoff layhe
www.lamar-uk.co.uk
> ----------
> From: Brian Ellis[SMTP:[log in to unmask]]
> Reply To: TechNet E-Mail Forum.;Brian Ellis
> Sent: 10 February 2000 07:45
> To: [log in to unmask]
> Subject: Re: [TN] FR4 Flame Retardant Agents
>
> Paul
>
> Am not a toxicologist, but I understand that the organobromides are
> loosely crosslinked
> into the epoxy and that they function by releasing hydrogen bromide and
> some other
> nasties on heating beyond about 350°C. This HBr is the actual
> extinguishing agent. HBr
> is decidedly very toxic and corrosive. Most organobromides are more or
> less toxic and
> environmentally unfriendly. Some of the other released compounds may also
> be
> ozone-depleting. However the quantities are relatively small.
>
> FR-4 without the organobromides is called G-10 and supports continuous
> combustion in
> air. It also produces toxic vapours, although less so and, of course, no
> organobromides.
>
> Brian
>
> Paul Klasek wrote:
>
> > Could you fellows enlighten me on toxicity of this additives please ,
> > and what goes into "standard" FR4 ?
> >
> > Debate circulates about what harm can charring board do in a ventilator
> :
> > With or without retardant :
> > How far is the standard glass laminate prone to ignition/combustion/char
> and
> >
> > what would be the effects of toxins generated ?
> >
> > Thanks a lot
> >
> > Paul Klasek
> > http://www.resmed.com
> >
> > ##############################################################
> > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> > ##############################################################
> > To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in
> > the body:
> > To subscribe: SUBSCRIBE TECHNET <your full name>
> > To unsubscribe: SIGNOFF TECHNET
> > ##############################################################
> > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
> additional
> > information.
> > If you need assistance - contact Gayatri Sardeshpande at [log in to unmask]
> or
> > 847-509-9700 ext.5365
> > ##############################################################
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in
> the body:
> To subscribe: SUBSCRIBE TECHNET <your full name>
> To unsubscribe: SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
> additional
> information.
> If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
> 847-509-9700 ext.5365
> ##############################################################
>
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################
|
|
|