Re: copper etching

From: Marshall Dudley (mdudley_at_king-cart.com)
Date: 12/28/04 

Date: Tue, 28 Dec 2004 14:27:30 -0500

Steve Turner wrote:

> >The etchant of choice would most likely be sodium persulphate, inexpensive,
> >and more environmentally friendly than any of the others, including FeCl3.
>
> I've seen this allegation about FeCl3 a number of times. I don't
> understand it. Why should FeCl3 be environmentally unfriendly?
>
> Steve Turner

It is designated as a hazardous substance under section 311(b)(2)(A) of the
Federal Water Pollution Control Act and further regulated by the Clean Water Act
Amendments of 1977 and 1978.

OSHA: Hazardous by definition of Hazard Communication Standard (29 CFR 1920.1200)

TDG (Canadian DOT) classifies it as 8: Corrosive liquid and 9.2: Environmentally
hazardous material

It has the following health effects:

*****************************************************************************
Potential Health Effects:

Inhalation: Irritation to mucous membranes, difficulty breathing

Skin Contact: Irritation and possibly burns

Eye Contact: Irritation and possibly burns

Ingestion: Irritation of the mouth and stomach. Symptoms of severe poisoning
include stomach pain, vomiting, diarrhea, dehydration, shock, pallor, weak pulse,
drowsiness, dilated pupils, and coma.

Chronic Effects: Repeated dosage may cause hemosiderosis with possible damage to
the liver and pancreas.

Carcinogenicity: Ferric chloride is not classified as carcinogenic by ACGIH
(American Conference of Governmental Industrial Hygienists) or IARC (International
Agency for Research on Cancer), not regulated as carcinogens by OSHA (Occupational
Safety and Health Administration) and not listed as carcinogens by NTP (National
Toxicology Program).

I think the answer as far as being unfriendly to the environment may be in this
document:

http://www.pesticideinfo.org/Ref_Aquire.jsp?Rec_Id=PC35156&ReferenceNumber=2453

Marshall