Laboratory Testing

Laboratory testing should be performed as the final option. Even for regulatory submission, attempts should be made to obtain data from other sources and where such data is not available, you need to ask where testing is actually possible. And if you still find that work is required to enable an adequate assessment of the chemical or that a regulatory agency demands that such work should be performed, you are then faced with decisions on how to go about that testing.

Note that for self-classification of substances and preprations and for justification of SDSs and Labelling, good scientifically sound data is acceptable even if not conducted to the precise guidelines and if not performed to GLP. Denehurst can offer advice on justification of data and will endeavour to avoid further testing.

Guidelines and GLP

Technical guidelines for testing have been agreed by members of the Organisation for Economic Co-operation and Development (OECD). The same organisation has also provided guidelines for Good Laboratory Practice (GLP) to provide a quality system for the testing.

However, following a test guideline and filling in the appropriate forms to claim GLP compliance is not necessarily a substitute for good science and each study performed should be conducted in the best way to meet the objectives of that study for that particular chemical. Guidelines are what they say: guidelines. They are designed to help and not restrict the use of science.

List of guidelines

The OECD Guidelines for the Testing of Chemicals are available to buy from the OECD, either individually or as a set of two binders containing loose-leaf paper copies. Alternatively, the Guidelines are also available on CD-ROM. Draft guidelines can be downloaded free for consultation from the OECD web-site.

The EU Guidelines were published in Directive 92/69/EEC as Annex V of Directive 67/548/EEC. Over the years since publication, amendments to these methods have been made and new guidelines introduced. Most of the guidelines are transcripts of OECD guidelines (the most notable exceptions being flammability and explosivity guidelines).

The EU guidelines can be downloaded for free from the European Chemicals Bureau web-site http://ecb.jrc.it/testing-methods/

Australian guidelines and those of many other countries are based firmly on OECD methods, although the US and Japan notably have some restrictions on what they require. To overcome national differences, the OECD guidelines are often with phrases such as ‘can be’ or ‘may be included’.

Good Laboratory Practice (GLP)

In many ways, GLP is common sense. The basic theology of GLP is that thou shalt record everything and leave a data trail for others to follow behind you. It is easy to get bogged down by GLP and make it the over-riding criteria to follow when conducting laboratory work. However, it is important not to lose sight of science and GLP has the potential to stifle open investigation.

Somewhere in the middle is a sound compromise. GLP sets important standards for recording data, reporting, reviewing and maintaining records. It does not guarantee the quality of the data being recorded and a balance between good science and good working practice is the goal to aim for.

GLP is required for regulatory submissions around the World, although if you only intend to use the data for the purposes of safety data sheets or labelling, the need to run the test to GLP standards must be questioned. The main reason for questioning it is when a flash point study that takes about an hour to perform, can take up to a month to report at a cost of up to € 1000 if performed to meet GLP.

OECD / EC Test Method index

OECD

TG No.

EU

Guideline

Study Description

101

UV-Vis Absorption spectra

102

A1

Melting point

103

A2

Boiling point

104

A4

Vapour pressure

105

A6

Water solubility

106

C18

Adsorption / desorption in soils (batch equilibrium method)

107-117-122

A8

Partition coefficient (shake flask, HPLC, pH-metric)

108

Complex formation ability in water

109

A3

Density

110

Particle size distribution

111

C7

Hydrolysis as a function of pH

112

Dissociation constant

113

Screening study for thermal stability in air

114

Viscosity of liquids

115

A5

Surface tension of aqueous solutions

116

A7

Fat solubility

118

A18

Polymer number-average molecular weight

119

A19

Low molecular weight content of polymers

120

A20

Solution/extraction behaviour of polymers in water

A21

Oxidising properties, liquids

121

C19

Estimation of adsorption coefficient in sewage sludge by HPLC

A9

Flash point

A10-A11

Flammability, solids / gasses

A12

Flammability in contact with water

A13

Spontaneous combustion

A14

Explosivity

A15

Auto-ignition, liquids

A16

Auto flammability, solids

A17

Oxidising properties

A21

Oxidising properties, liquid

OECD

TG No.

EU

Guideline

Study Description

201

C3

Algal growth inhibition

202

C2

Daphnia immobilisation

203

C1

Acute fish toxicity

204

Prolonged toxicity to fish

205

Acute bird dietary toxicity

206

Bird reproduction

207

C8

Earthworm toxicity

208

Higher plant toxicity

209

C11

Activated sludge respiration inhibition

210

Fish, early life stage

211

C20

Daphnia reproduction toxicity

212

C15

Fish, short-term test on embryo / sac-fry

213

C16

Bees, acute oral toxicity

214

C17

Bees, acute contact toxicity

215

C14

Fish, Juvenile growth test

216

Soil micro-organisms

217

Soil micro-organisms carbon transformation

218

Sediment-water chironomid toxicity (spiked sediment)

219

Sediment-water chironomid toxicity (spiked water)

220

Enchytraedae reproduction

221

Lemna growth inhibition

OECD

TG No.

EU

Guideline

Study Description

301A

C4a

Ready biodegradation, DOC die-away

301B

C4c

Ready biodegradation, CO₂ evolution test