Required skills

Required skills include

using appropriate materials equipment and procedures to prepare solutions

following appropriate occupational health and safety OHS and hygiene procedures if appropriate

using all equipment safely and efficiently

using enterprise procedures to calculate concentrations

identifying solutions not fit for use

using titrations to determine the concentration of solutions

labelling storing and disposing of solutions appropriately

recording and presenting data appropriately

Required knowledge

Required knowledge includes

relevant biological chemical food and laboratory terminology

principles of metrology

the international system of units SI

concentration terms such as ww wv vv ppm mgL and molarity

basic theory of acids bases salts buffers and neutralisation

enterprise procedures for preparing solutions

calculations required to prepare specified amounts of solutions of specified concentration

appropriate OHS procedure for preparing handling and disposal of solutions

use of material safety data sheets MSDS

relevant health safety and environment requirements

The Evidence Guide provides advice on assessment and must be read in conjunction with the performance criteria required skills and knowledge range statement and the Assessment Guidelines for the Training Package

Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit

Assessors should ensure that candidates can

prepare working solutions in compliance with relevant standards appropriate procedures andor enterprise requirements

follow OHS procedures to safely use laboratory chemicals glassware and equipment

make up working solutions according enterprise procedures

check existing stocks of solutions as being fit for purpose

Context of and specific resources for assessment

This unit of competency is to be assessed in the workplace or simulated workplace environment

This unit of competency may be assessed with

MSLA Record and present data

MSL922001A Record and present data

MSLA Participate in laboratoryfield workplace safety

MSL943002A Participate in laboratory/field workplace safety.

Resources may include

standard laboratory equipped with appropriate equipment and reagents

SOPs and testing methods

access to appropriate containers and storage facilities

Method of assessment

The following assessment methods are suggested

inspection of solutions prepared labelled and stored by the candidate

review of solution records and workplace documentation completed by the candidate

feedback from peers and supervisors

observation of the candidate preparing working solutions

oral or written questioning

In all cases practical assessment should be supported by questions to assess underpinning knowledge and those aspects of competency which are difficult to assess directly

Where applicable reasonable adjustment must be made to work environments and training situations to accommodate ethnicity age gender demographics and disability

Access must be provided to appropriate learning andor assessment support when required

The language literacy and numeracy demands of assessment should not be greater than those required to undertake the unit of competency in a work like environment

This competency in practice

Industry representatives have provided the case studies below to illustrate the practical application of this unit of competency and show its relevance in a workplace setting

Manufacturing

When starting materials used for the manufacture of common household materials are in transit from the supplier to the manufacturer they may degrade if subjected to conditions such as heat moisture light and oxygen Even when the supplier ships quality materials to the manufacturing plant the materials may be substandard when they arrive Quality control tests are designed to test starting materials to ensure they are within specification For example aspirin forms salicylic acid when stored under adverse conditions Laboratory assistants prepare and monitor the quality of solutions such as ferric chloride solution which gives an intense violet colour when added to salicylic acid but gives no colour with aspirin Absence of the violet colouration indicates that breakdown of the aspirin hasnt occurred

Biomedical

A laboratory assistant made up litre of buffer solution using buffer tablets and a litre volumetric flask as specified in the method To ensure the solution was suitable for use the assistant measured the pH and found it was within acceptable range The assistant then appropriately labelled a storage vessel and stored the buffer according to requirements By following enterprise procedures the shelf life of the buffer was maximised

Environmental

An environmental laboratory is contracted to determine the acidity of water samples taken from local lakes and streams A laboratory assistant is required to make up small batches of M sodium hydroxide and to determine its concentration by titrating it against a standard solution of potassium acid phthalate using phenolphthalein indicator This procedure is carried out monthly to ensure that the concentration of the sodium hydroxide solution is accurately known Alternatively the laboratory assistant may be required to prepare and standardise a fresh batch of sodium hydroxide on a monthly basis In this case heshe must understand the underpinning knowledge of basic acidbase theory potential problems of interferences such as slow absorption of carbon dioxide by sodium hydroxide solution so as to ensure that the concentrations of workup solutions are accurately known Heshe must also be skilled in calculating and performing dilution when required to prepare such low concentrations M of working solutions

Codes of practice

Standards, codes, procedures and/or enterprise requirements

Concepts of metrology

Typical test solutions

Laboratory equipment

Hazards

Safety precautions

Monitoring quality of solutions

Occupational health and safety (OHS) and environmental management requirements