Reviewed and Approved By:
Catherine L. Fiore, PSFC Safety Officer
Standard Operating Procedures for Use of Caustics and Acids Other
Author: P. Thomas/A. Eckmann
Date: February 10, 1997, Revised 12/4/1998 by C. Fiore
Persons Responsible: Paul Thomas - NW16-130
Bob Childs - NW21-109
Ed Fitzgerald - NW21-107
This document outlines the hazards involved with the use of acids,
alkalies, and any
caustic or corrosive materials. It details procedures to be followed to
minimize the risk of exposure of Plasma Science and Fusion Center employees
during etching, cleaning, and electropolishing procedures utilizing these
chemicals. These procedures are appropriate for the handling and use of most
caustic, corrosive, and irritating materials.
This procedure covers employee safety during the handling, and use of
chemicals during etching, cleaning, and electropolishing procedures. Generally
these procedures range from the use of a few milliliters or less of
concentrated acids and alkalies to prepare small volumes of solution, to the
preparation of up to two liters of concentrated solutions.
Failure to follow this procedure could result in severe skin and eye
irritation or burns
from direct contact with acids and alkalies. Alkalies such as sodium
hydroxide, potassium hydroxide, and ammonium hydroxide penetrate tissues more
rapidly than acids and may cause irreversible eye damage if eye contact occurs.
Alkali and acid vapors are irritating and may be corrosive to the respiratory
Primary Irritant - Capable of causing tissue damage and burns
resulting from direct contact.
The supervisor or responsible person shall designate employees who are
required to work with acids and alkalies, and train them regarding the health
and physical hazards and appropriate work procedures. The supervisor or
responsible person shall ensure that necessary personal protective equipment
and spill control supplies are available to employees. The supervisor or
responsible person shall ensure that operations utilizing acids and alkalies
are performed in accordance with good work practices in adequately ventilated
Employees shall be familiar with the hazards associated with acids and
with appropriate spill and emergency procedures described in this document.
The user shall be trained in the use of appropriate personal protective
equipment. If respiratory protection is to be used, such protection shall have
been obtained through the Industrial Hygiene Office and employees shall have
received fit tests and appropriate medical examinations.
Hydrofluoric acid has unique health and physical hazards and requires special
handling, spill control, and first aid procedures. Procedures for the use and
handling of hydrofluoric acid are covered in a separate SOP document.
- Protective gloves. Gloves shall be worn whenever acid and
alkali solutions are handled. Lightweight PVC gloves should be sufficient to
prevent incidental contact with dilute solutions. Heavy nitrile or other
impervious gloves shall be worn whenever concentrated solutions are dispensed.
Discard gloves if any holes or leaks develop.
- Eye and Face Protection. Splash-proof chemical goggles, or
safety glasses with side shields and face shields are required when dispensing
or handling concentrated acids and alkalies. Safety glasses are required when
using or handling more dilute acid or alkali solutions. Contact lenses may not
be worn unless splash-proof chemical goggles are also used.
- Protective Clothing. A lab coat, in addition to protective
gloves, is the minimum required protection for handling acids and alkalies.
Impervious aprons shall be worn while transferring acids or alkalies in
quantities greater than 10 milliliters.
- Spill Materials. Neutralizing, absorbent materials should be
obtained to control spills. Appropriate spill control materials may be
obtained from VWR. Sweeping compounds may be added to dry corrosive powder
spills, which may then be carefully scooped or swept up to avoid raising dust.
An appropriate container for holding any spill clean-up materials is also
required. Spill pillows are available to members of the Alcator Group in the
Alcator vacuum shop, NW21-167.
- Prior to initial assignment to the operation, read the Material
Safety Data Sheet and become familiar with the hazards of corrosive acid and
- Perform operations involving the use or transfer of acids and alkalies
inside a laboratory fume hood whenever possible. If a laboratory fume hood is
not available, perform operations in a well-ventilated area.
- Do not use acids or alkalies while wearing open-toe footwear, or shorts.
(These items of apparel are not appropriate for laboratory work at any time.)
- Determine what the appropriate spill materials are by referring to the MSDS,
or by consulting with the Industrial Hygiene Office, the Chemical Hygiene
Officer, or the supervisor. Locate appropriate spill control materials and
ensure that an adequate supply is available, including an appropriate container
to hold any contaminated spill clean-up materials.
- Ensure that an eyewash and safety shower are located nearby to flush the
eyes or skin in the event of contact. If there is not an eyewash in the
immediate vicinity of the operation, another employee who can rapidly escort
the affected employee to an eyewash shall remain in the general vicinity of the
- Breakable containers of acids and alkalies must be carried in non-breakable
- Wear protective goggles, face shield, gloves, lab coats, or other protective
clothing and equipment as required by the job.
- Always add acid to water, not the reverse. If the reverse is done, violent
spattering and breakage of glass containers may occur.
- Do not leave tongs, stirrers, caps etc., which have been contaminated with
acids or alkalies where other people may pick them up or otherwise come into
contact with them. Be careful not to contaminate work surfaces with these
materials. If the outside surfaces of chemical storage containers become
contaminated, flush the residue with water and dry the container before putting
- Any unattended containers must be labeled including the chemical identity
of the material and the associated health and physical hazards. If it is
infeasible to do this and containers must be left in an area unattended by the
user, place a placard or sign adjacent to the container indicating the identity
and hazard information.
- Cap acid and alkali containers securely and store them on low shelves to
minimize the risk of accidental breakage.
- DO NOT store strong acids and strong alkalies together. If an
accident results in rupture or breakage of the containers and they come into
contact, they will react violently.
- DO NOT store oxidizing corrosive materials including nitric acid and
bleach, together with flammable solvents. The cleaning solution formed by
adding sulfuric acid to sodium dichromate is a very strong oxidant which can
violently react with organic matter. It ignites on contact with alcohol or
acetic acid, and containers involved in fires may explode violently. Severe,
slow-healing burns are caused by contact with sulfuric acid/sodium dichromate
- When the work has been completed and personal protective equipment has been
removed, wash hands thoroughly with soap and water.
- If a spill occurs, clean it up immediately in accordance with procedures
described in this document. Note that laboratory furnishings (e.g., benches
and sinks) sold as "acid resistant" withstand an acid spill unscathed for only
a few seconds.
The supervisor or responsible person shall supply this procedure to
employees and verify that they understand it. Employees should understand the
health and physical hazards of acids and alkalies. The difficulty of rinsing
alkalies from tissue and the ability of alkalies to inflict irreversible damage
to the eyes, and the incompatibility of oxidizing acids or caustics with
organic solvent should be emphasized.
- Refer to the product Material Safety Data Sheet for proper spill clean-up
- Do not attempt to clean up any large spills, especially if the vapors from
the spill result in noticeable eye or respiratory irritation. For large
spills, restrict access to the spill area and dial 100. Small spills may be
cleaned up by the person who caused the spill.
- Do not attempt to clean up any spills without wearing gloves, eye, and face
protection. Acids and alkalies may contaminate footwear during clean-up of a
spill. If there is any possibility of contamination of footwear while cleaning
up the spill, obtain shoe coverings or rubber boots.
- Control the spill with an appropriate neutralizing agent. Scoop the
material into a suitable container. Vermiculite or sweeping compound may be
used to facilitate the clean up of dry alkali powders.
- Carefully rinse contaminated areas with water. Sponges used to absorb the
rinse water should be added to the spill clean-up wastes. Paper towels may
only be used to wipe up dilute acids since strong acids may cause oxidation and
heating of organic materials such as paper.
- Label the waste container and contact the Safety Office (ext. 3-4736) for
pick up of the spill clean-up materials.
First Aid Procedures:
- Any splash or exposure of the skin should be immediately, thoroughly
flushed for 5 - 15 minutes. Do not allow contaminated clothing to remain in contact with
the skin. If skin irritation or dermatitis develops, the affected individual
shall be examined at the MIT Medical Department and referred to Environmental
Medical Services for a follow-up.
- In the event of eye contact, 15 minutes of flushing with water is required.
This is especially important with alkalies, which soak down deep into tissues.
It is necessary to wash repeatedly in order to get strong alkaline materials
out. The affected individual will likely require assistance to hold the eyelids
open during the flushing. If any eye contact with concentrated acids or
alkalies occurs, the affected individual shall be examined at ophthalmology
(dial ext.3-4481). Dial 100 for emergencies.
- If an individual has lost consciousness, dial 100 for emergency
- In the unlikely event that an individual ingests acids or alkalies,
immediately call the Medical Department or dial 100 for emergency assistance.
Waste Disposal Procedures:
Acid and alkali solutions may not be put down the drain, whether or not
they have been neutralized. Any questions on this subject may be directed to
Bill vanSchalkwyk of the Safety Office (ext. 3-4736).
Place acid and alkali wastes into clearly labeled, appropriate containers
designated for this purpose. Do not mix different kinds of acids together
unless instructed to do so by the supervisor with approval from the CHO.
Unfilled waste containers must be held in a satellite accumulation area in
accordance with MIT and PSFC hazardous waste procedures, then disposed of
accordingly. See the PSFC Hazardous Waste Procedure.
- MIT Accident Prevention Guide, Chapter 8. Hazardous Materials, Section
8-1, Acids and Alkalies
This page maintained by Catherine L. Fiore FIORE@PSFC.MIT.EDU