Science Rd Cottage A10
NSW 2006 AUSTRALIA
Telephone +61 2 9351-2848
Facsimile +61 2 9351-2558
E-mail office@bio.usyd.edu.au
Risk Assessment for hazardous substances/procedure
Process
Concentrated acids – handling and diluting Date 9/12/05
Assessor’s Name R. Hinde in consultation with M. Joseph
Chemical(s)
Quantity used (mass/volume) several ml to several hundred ml
Phone 9351 2277
9351 4098 concentrated acids (including, but not limited to, nitric, sulfuric, hydrochloric, acetic acids)
Area of use: School laboratories and prep rooms
Nature of the risk or possible injury
Risk assessment classifications
(see matrix below)
Spills, chemical reactivity
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Found a hazard? Think about:
How likely is it to hurt someone?
 very likely ++ could happen regularly likely + could happen occasionally unlikely - could happen, but only rarely very unlikely -- could happen, but probably never will
How severely could it hurt someone?

!!! kill or disable
1
2
3
4
!! several days
off work
2
3
4
5
! first aid
3
4
5
6
The numbers show how important it is to do something:
1 do something immediately
6 do something when possible.
_____________________________________________________________________________
1

Is the substance/procedure hazardous? Yes
If yes please list details of substances or hazardous aspects of procedure;
Hazards involved in handling concentrated acids are:
Spills – acids are corrosive to human tissue and to other substances in laboratories.
Spilled acid may cause anything from irritation to severe chemical burns.
Chemical reactivity – Acids react violently with many other substances, in some cases causing explosions, sputtering or rapid oxidation (refer to MSDS sheets for acids in use at any given time). Products of reaction may be toxic gases or solutions.
Inhalation - most acids are volatile and therefore pose a risk of inhalation. Heating during reactions will increase volatility. They can cause anything from irritation to severe burns if inhaled.
Ingestion - concentrated acids may be toxic and are certainly dangerously corrosive if ingested
Splashing – may occur during pouring or during reactions (see”Spills”, above).
Heating
– during dilution or other reactions, solutions may become hot, leading to burns
(due to temperature, rather than chemical reactions).
Are the appropriate Material Safety Data Sheets (MSDS) available in the work area
It is essential for each lab. to have MSDS for all acids stored and/or used in the laboratory.
If there is a likelihood of exposure, please state probable route
–
Skin, inhalation, ingestion
Is it necessary to perform/ use this procedure/substance in a fume hood or with local exhaust Yes
Are special storage, transport or disposal procedures required? Yes
If “Yes”, please explain
Concentrated acids should be transported in outer containers that will protect bottles from breakage and contain spills.
Splash-proof goggles or full face shields are required.
PVC or neoprene gloves and apron, and coveralls should be worn when handling concentrated acids.
Closed shoes are essential, and rubber boots preferable.
Contaminated waste is disposed of according to the MSDS for each acid.
FOR DILUTING ACIDS:
 Work in a fume hood.
 A container that is large enough to contain all the diluted material, and retain any splashes, is required.
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 The water must be added to the container first. The acid is then poured into it slowly
– this minimizes heating, splashing and sputtering.
 If the mixture becomes hot, allow it to cool before decanting or using it.
What personal protective equipment is required? Gloves, faceshield or splashproof goggles, lab coat, PVC or neoprene apron if possible, closed shoes or rubber boots.
Work in fume hood.
Is an eye wash/safety shower located near the work area? Yes
Is fire equipment nearby? Yes
What steps have been taken to control the risks associated with this substance/procedure
Where possible buy dilute formulations.
Where this is not possible, ensure that concentrated acids are handled by trained personnel only. (and see above).
What is the level of proficiency of the users of this substance/procedure i.e undergraduate, researcher, post graduate etc.
Experienced staff and postgraduate students (supervised until proficient).
Do the intended users have adequate training/experience Yes, staff should all be.
Students require supervision until proficient in handling any acids they need to use.
If no, what training is required? Demonstration and supervision by experienced staff.
Any other relevant information Undergraduates should not handle concentrated acids.
.
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