ASTM E1733-95(2008)
(Guide)Standard Guide for Use of Lighting in Laboratory Testing
Standard Guide for Use of Lighting in Laboratory Testing
SIGNIFICANCE AND USE
The information in this guide is designed to allow investigators conducting research or tests of environmental relevance to select appropriate light sources.
Investigators will be able to make reasonable selections of light sources based on cost, the requirements of the test organisms, and the properties of the test chemicals.
These methods have major significance for the comparison of results between laboratories. Investigators at different sites will be able to select similar light sources. This will provide standardization of a factor that can have major impact on the effects of hazardous chemicals.
SCOPE
1.1 The use of artificial lighting is often required to study the responses of living organisms to contaminants in a controlled manner. Even if the test organism does not require light, the investigator will generally need light to manipulate the samples, and the test might be conducted under the ambient light of the laboratory. One will need to consider not only whether the particular test organism requires light for growth, but also whether the environmental compartment relevant to the test is exposed to light and, if so, what the attributes of light are in that compartment. The light could affect growth of the organism or toxicity of a contaminant, or both. For instance, it has been shown that the toxicity of some organic pollutants is enhanced dramatically by the ultraviolet (UV) radiation present in sunlight (1, 2). Furthermore, the level of ambient lighting in the laboratory (which might affect the test) is not standardized, nor is it comparable to natural environments. It is thus important to consider lighting in all forms of environmental testing. When light is used in the test, one should determine whether the spectral distribution of the radiation source mimics sunlight adequately to be considered environmentally relevant. Also, the container or vessel for the experiment must be transparent, at the point of light entry, to all of the spectral regions in the light source needed for the test.
1.2 It is possible to simulate sunlight with respect to the visible:UV ratio with relatively inexpensive equipment. This guide contains information on the types of artificial light sources that are commonly used in the laboratory, compositions of light sources that mimic the biologically relevant spectral range of sunlight, quantification of irradiance levels of the light sources, determination of spectral outputs of the light sources, transmittance properties of materials used for laboratory containers, calculation of biologically effective radiation, and considerations that should go into designing a relevant light source for a given test.
1.3 Special needs or circumstances will dictate how a given light source is constructed. This is based on the requirements of the test and the environmental compartment to which it is targeted. Using appropriate conditions is most important for any experiment, and it is desirable to standardize these conditions among laboratories. In extreme cases, tests using unusual lighting conditions might render a data set incomparable to other tests.
1.4 The lighting conditions described herein are applicable to tests with most organisms and using most chemicals. With appropriate modifications, these light sources can be used under most laboratory conditions with many types of laboratory vessels.
1.5 The attributes of the light source used in a given study should list the types of lamps used, any screening materials, the light level as an energy fluence rate (in W m−2) or photon fluence rate (in μmol m−2 s−1), and the transmission properties of the vessels used to hold the test organism(s). If it is relevant to the outcome of a test, the spectral quality of the light source should be measured with a spectroradiometer and the emission spectrum provided graphically for reference.
1.6 The sections of this guide are arranged as follows:
TitleSection Ref...
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E1733 − 95(Reapproved 2008)
Standard Guide for
Use of Lighting in Laboratory Testing
This standard is issued under the fixed designation E1733; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.3 Special needs or circumstances will dictate how a given
lightsourceisconstructed.Thisisbasedontherequirementsof
1.1 The use of artificial lighting is often required to study
the test and the environmental compartment to which it is
the responses of living organisms to contaminants in a con-
targeted. Using appropriate conditions is most important for
trolledmanner.Evenifthetestorganismdoesnotrequirelight,
any experiment, and it is desirable to standardize these condi-
the investigator will generally need light to manipulate the
tionsamonglaboratories.Inextremecases,testsusingunusual
samples, and the test might be conducted under the ambient
lighting conditions might render a data set incomparable to
light of the laboratory. One will need to consider not only
other tests.
whether the particular test organism requires light for growth,
but also whether the environmental compartment relevant to
1.4 The lighting conditions described herein are applicable
thetestisexposedtolightand,ifso,whattheattributesoflight
to tests with most organisms and using most chemicals. With
are in that compartment. The light could affect growth of the
appropriate modifications, these light sources can be used
organism or toxicity of a contaminant, or both. For instance, it
under most laboratory conditions with many types of labora-
has been shown that the toxicity of some organic pollutants is
tory vessels.
enhanceddramaticallybytheultraviolet(UV)radiationpresent
2 1.5 The attributes of the light source used in a given study
insunlight (1, 2). Furthermore,thelevelofambientlightingin
shouldlistthetypesoflampsused,anyscreeningmaterials,the
thelaboratory(whichmightaffectthetest)isnotstandardized,
−2
light level as an energy fluence rate (in W m ) or photon
nor is it comparable to natural environments. It is thus
−2 −1
fluencerate(inµmolm s ),andthetransmissionproperties
important to consider lighting in all forms of environmental
of the vessels used to hold the test organism(s). If it is relevant
testing. When light is used in the test, one should determine
to the outcome of a test, the spectral quality of the light source
whetherthespectraldistributionoftheradiationsourcemimics
shouldbemeasuredwithaspectroradiometerandtheemission
sunlightadequatelytobeconsideredenvironmentallyrelevant.
spectrum provided graphically for reference.
Also, the container or vessel for the experiment must be
transparent, at the point of light entry, to all of the spectral
1.6 The sections of this guide are arranged as follows:
regions in the light source needed for the test.
Title Section
Referenced Documents 2
1.2 It is possible to simulate sunlight with respect to the
Terminology 3
visible:UV ratio with relatively inexpensive equipment. This
Summary of Guide 4
Significance and Use 5
guide contains information on the types of artificial light
Safety Precautions 6
sources that are commonly used in the laboratory, composi-
Lamps 7
tions of light sources that mimic the biologically relevant
Artificial Lighting 7.1
Light Sources 7.2
spectralrangeofsunlight,quantificationofirradiancelevelsof
Construction of Artificial Light Sources that Mimic Sunlight 8
the light sources, determination of spectral outputs of the light
Sunlight 8.2
sources, transmittance properties of materials used for labora-
Visible Light 8.2
Visible Light Plus UV-B Radiation 8.3
tory containers, calculation of biologically effective radiation,
Simulated Solar Radiation 8.4
and considerations that should go into designing a relevant
Transmission Properties of Lamp Coverings and Laboratory Vessels 9
light source for a given test.
Lamp Coverings 9.2
Laboratory Vessels 9.3
Measurement of Light 10
Light Components 10.1
Measurement of Light Quantity 10.2
ThisguideisunderthejurisdictionofASTMCommitteeE50onEnvironmental
Spectroradiometry 10.3
Assessment, Risk Management and CorrectiveAction and is the direct responsibil-
Biologically Effective Radiation 11
ity of Subcommittee E50.47 on Biological Effects and Environmental Fate.
Considerations for Designing Light Sources for Environmental Testing 12
Current edition approved Feb. 1, 2008. Published February 2008. Originally
ε1
approved in 1995. Last previous edition approved in 2002 as E1733–95(2002) .
1.7 The values stated in SI units are to be regarded as the
DOI: 10.1520/E1733-95R08.
standard. The values given in parentheses are for information
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
this guide. only.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1733 − 95 (2008)
−2 −1
1.8 This standard does not purport to address all of the is equivalent to µEinstein m s . An Einstein is Avogadro’s
safety concerns, if any, associated with its use. It is the number (a mole) of photons and was used for quantum
responsibility of the user of this standard to establish appro- measurements but is no longer an SI — supported unit (see
priate safety and health practices and determine the applica- IEEE/ASTM SI 10 ).) The conversion between energy fluence
bility of regulatory limitations prior to use. Specific precau-
rate and photon fluence rate is as follows:
tionary statements are given in Section 6.
22 21 22 23
µmolm s 5Wm 3 λ~nm! 38.36 310 (1)
3.2.2.1 Discussion—This illustrates an inherent problem of
2. Referenced Documents
converting between light units: the energy is wavelength (λ)
2.1 ASTM Standards:
dependent, so conversion between energy and quantum units
E943Terminology Relating to Biological Effects and Envi-
requires knowledge of the spectral distribution of the light
ronmental Fate
source (see 10.2.4 for conversion guidelines).
E1218Guide for Conducting Static Toxicity Tests with
3.2.3 fluorescence—emission of light by an excited atom or
Microalgae
molecule.
E1415Guide for Conducting Static Toxicity Tests With
Lemna gibba G3
3.2.4 foot-candle—lumen per ft (see 3.2.8).
E1598Practice for Conducting Early Seedling GrowthTests
3.2.5 frequency, (ν)—description of radiation as the number
(Withdrawn 2003)
of wave peaks passing a point in space per unit time. Units are
IEEE/ASTM SI 10 Standard for Use of the International
−1
normally cycles s or Hz.
System of Units (SI): The Modern Metric System
3.2.6 IR—infrared radiation (wavelength range, 760 nm to
3. Terminology
2000 nm).
3.1 Definitions—The words “must,” “should,” “may,”
3.2.7 irradiance—quantity of radiant energy received by a
“can,” and “might” have very specific meanings in this guide.
unit area per unit time. This is the same as the energy fluence
“Must” is used to express an absolute requirement, that is, to
rate.
state that the conditions ought to be designed to satisfy
3.2.8 lumen—light emitted by a point source of 1 cd. It is a
appropriate lighting, unless the purpose of a test requires a
unit of luminosity or brightness used in photography and stage
differentdesign.“Must”isonlyusedinconnectionwithfactors
lightingandisirradiancebasedonsensitivityofthehumaneye
that directly relate to the acceptability of specific conditions.
(maximum sensitivity at 550 nm). It has the same dimensions
“Should” is used to state that a specified condition is recom-
as watts because it is equivalent to irradiance by definition.
mended and ought to be met if possible.Although violation of
However, the lumen as a measurement is wavelength depen-
one“should”israrelyaseriousmatter,violationofseveralwill
dent(1lmat λ560nmis1.5mW,and1lmat λ430nmis127
oftenrendertheresultsofatestquestionable.Termssuchas“is
mW) (see 10.2.3), so extreme care should be used with this
desirable,” “is often desirable,” and “might be desirable” are
unit. If possible, light levels based on lumens should be
used in connection with less important factors. “May” is used
convertedtoanappropriatelightunitforenvironmentalstudies
to mean is (are) allowed to, “can” is used to mean is (are) able
−2 −2 −1
(for example, W m or µmol m s ) (see 10.2.4 for
to,and“might”isusedtomeancouldpossibly.Thustheclassic
conversion guidelines).
distinction between may and can is preserved, and might is
never used as a synonym for either “may” or “can.”
3.2.9 lux—lumen per m (see 3.2.8).
3.2 Descriptions of Terms Specific to This Standard (see
3.2.10 photon—one quanta (or single indivisible packet) of
also Terminology E943):
light or radiant energy.Amole of photons (an Einstein) equals
3.2.1 fluence—amount of light per unit area, expressed as 23
Avogadro’s number (6.022×10 ). The energy of a photon is
−2 −2
energy (J m ) or photons (mol m ). This is sometimes
related to its frequency or wavelength and is given by E=
equated to light dose. −34
hν = hc/λ, where h = planks constant (6.6 × 10 Js),
8 −1
3.2.2 fluence rate—flow rate of light, flux of light, or the c=speed of light (3×10 ms ), ν=frequency, and λ
−1
amount of light per unit area per unit time. It is sometimes
=wavelength (if c is used in m s , then λ must also be in m).
referred to as light intensity, although this is not a desirable
3.2.11 spectral distribution—a description of a light source
term because intensity refers to the amount of radiation in a
as the quantity of light at each wavelength.An energy spectral
unit angle. The energy fluence rate (also irradiance, energy
distribution is the energy of a light source given as a function
−2 −1
flow rate, or power) is usually given in units of J m s orW
of wavelength.Aphoton spectral distribution is the number of
−2 −1
m (1Js =1 W). The photon fluence rate (flow rate on a
photons in a light source as a function of wavelength.
−2 −1
quantumbasis)isusuallygivenintheunitµmolm s .(This
3.2.12 UV-A—ultraviolet A radiation (wavelength range,
320 to 400 nm).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.2.13 UV-B—ultraviolet B radiation (wavelength range,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
290 to 320 nm).
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3.2.14 UV-C—ultraviolet C radiation (wavelength range,
The last approved version of this historical standard is referenced on
www.astm.org. 200 to 290 nm).
E1733 − 95 (2008)
3.2.15 visible light—the spectral region visible to humans glasses or goggles that absorb UV radiation) available from
(wavelength range, 400 to 700 nm). This is the photosyntheti- most scientific supply companies. The spectral quality of the
cally active region of the spectrum as well. eyeware should be checked periodically with a UV/vis spec-
trophotometer. Transmission should be less than 0.1% for all
3.2.16 wavelength (λ)—the description of radiation (or ra-
wavelengths below 330 nm. Contact with skin is also to be
diantenergy)asthedistancebetweentwoconsecutivepeaksin
prevented.Ingeneral,alllightsourcesthatgenerateUV-Bwill
an electromagnetic wave. Units are normally in nm. The
generate some UV-C as well.
energy of a photon is inversely proportional to its wavelength.
Also, frequency×wavelength=speed of light.
6.4 Heat—Many light sources, especially short-arc lamps,
create a high fluence rate of IR radiation. Skin, clothing, and
4. Summary of Guide
other materials exposed to high levels of IR radiation are
4.1 This guide provides information on several types of subject to severe burns or may ignite.
laboratorylightsourcesandtheneedforstandardizedlighting.
6.5 Warning—Mercury has been designated by EPA and
The varieties of commercially available light sources and the
many state agencies as a hazardous material that can cause
spectralqualityoftheiroutputsarepresentedfirst.Thewaysin
central nervous system, kidney and liver damage. Mercury, or
which different lamps can be assembled to mimic sunlight are
its vapor, may be hazardous to health and corrosive to
then summarized. There is a discussion of the methods for
materials.Cautionshouldbetakenwhenhandlingmercuryand
measuring the amounts and spectral quality of light, and the
mercury containing products. See the applicable product Ma-
need for accurate standardized methods. Finally, a discussion
terial Safety Data Sheet (MSDS) for details and EPA’s website
on biologically effective radiation is included.
– http://www.epa.gov/mercury/faq.htm - for additional infor-
mation. Users should be aware that selling mercury and/or
5. Significance and Use
mercury containing products into your state may be prohibited
5.1 The information in this guide is designed to allow
by state law.
investigators conducting research or tests of environmental
7. Lamps
relevance to select appropriate light sources.
7.1 Artificial Lighting—The development of artificial light-
5.2 Investigators will be able to make reasonable selections
ing stems from two needs: (1) the requirement for inexpensive
of light sources based on cost, the requirements of the test
commercialandpubliclightingand(2)specializedlightingfor
organisms, and the properties of the test chemicals.
research and technology (see Table 1 for a listing of some of
5.3 Thesemethodshavemajorsignificanceforthecompari-
thelightsourcesavailable).Thereareessentiallytwowaysthat
son of results between laboratories. Investigators at different
lightcanbegeneratedfortoxicitytesting:(1)electricdischarge
sites will be able to select similar light sources. This will
lamps, those that are based on photon emission from an
provide standardization of a factor that can have major impact
electronically excited gas (for example, fluorescent and short-
on the effects of hazardous chemicals.
arc lamps); and (2) thermal lamps, those that are based on
photon emission from a heated filament (for example, incan-
6. Safety Precautions
descent lamps) (12, 13). Laser sources are not practical for
6.1 Many materials can affect humans adversely if precau-
most toxicology studies and are not discussed in this guide.
tions are inadequate. Therefore, eye and skin contact with
7.2 Light Sources:
radiation (especially UV) from all light sources should be
7.2.1 Fluorescent Lamps—Fluorescent lamps are based on
minimized by such means as wearing appropriate protective
excitationoflow-pressureHggasbyanelectriccurrent.When
eyeware, protective gloves (especially when washing equip-
the Hg atoms relax back to ground state, they emit photons at
mentorputtinghandsintestchambersorsolutions),laboratory
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.