ASTM D5588-97(2021)

• Abstract:

  SIGNIFICANCE AND USE; 3.1 Spoilage of paint in the container is often related to the use of contaminated raw materials, water (particularly recycled washwater), vessels, piping, and equipment in the manufacturing plant. There is a need for a simple method to determine the presence or absence of microorganisms in plants that manufacture paints and coatings. Such a determination enables the manufacturer to establish the point of contamination (that is, raw materials or problem housekeeping areas in the plant) to help in solving the spoilage problem. ; Note 1: Some contamination in plant areas is to be expected, since microorganisms are ubiquitous and cannot generally be eliminated practically (it is what an in-can preservative is supposed to control). Excessive levels of contamination or contaminated raw materials can exceed the capability of the preservative. If you have excessive contamination in the plant, there are methods for decontamination including steam, preservatives, bleach, etc. These should be discussed with your biocide supplier and used with care. Recovery of spoiled or contaminated products is often not feasible, so an adequate level of the appropriate biocide in conjunction with good plant housekeeping practices are essential. Your biocide supplier can also help here. ; 3.2 This test method may be used by persons without basic microbiological training, but some training on aseptic techniques would be recommended. ; Note 2: The reliability of the results obtained from this test method is extremely dependent on the techniques employed. Improper techniques can result in a sterile sample appearing to be contaminated, and even worse, a contaminated sample appearing to be sterile (see also 5.1). It is recommended that you consult with your biocide supplier, raw material supplier, or an independent testing laboratory to confirm questionable results.; SCOPE; 1.1 This test method covers a procedure for the determination of the microbial condition (contamination or sterility) of raw materials used in the manufacture of paint, and the microbial condition of paint and paint manufacturing areas. ; 1.2 The values in SI units are to be regarded as the standard. The values given in parentheses are for information only. ; 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. ; 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

• Status: Published
• Publication Date: 31-Oct-2021
• ICS: 87.040 - Paints and varnishes
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.28 - Biodeterioration

Overview

ASTM D5588-97(2021) is the internationally recognized standard test method for determining the microbial condition of paint, paint raw materials, and plant areas. Developed by ASTM International, this standard addresses a critical quality control measure within the paint and coatings manufacturing industry. Microbial contamination can lead to spoilage of paint products, impacting shelf-life, performance, and safety. ASTM D5588 provides a practical, relatively simple approach to detect the presence or absence of microorganisms in paints, raw materials, and manufacturing environments, supporting effective preventive actions and root cause investigations.

Key Topics

• Microbial Contamination: The standard supports detection of bacteria, fungi, and yeast in paint products, raw materials (such as water or resins), and production plant areas.
• Sampling and Testing: Guidance is provided for sampling both liquid and dry materials, and for surveying different plant locations, prioritizing areas most susceptible to microbiological growth, including recycled wash water, plant vessels, pipes, and equipment.
• Test Methods: Outlines use of commonly available agar plates (e.g., Tryptic Soy Agar and Potato Dextrose Agar) for microbial streaking and incubation, and clear rating systems for categorizing the degree of contamination.
• Best Practices: Emphasizes aseptic techniques and cleanliness during sampling and testing to maximize the accuracy of results. Even personnel with limited microbiological background can conduct the procedures, although some training is recommended.
• Interpretation and Reporting: Details how to evaluate colony growth, document findings with location and results, and employ a standardized scale for contamination.

Applications

Practical applications of ASTM D5588 include:

• Quality Assurance in Production: Regular monitoring of raw materials and plant environments for microbial contamination reduces risks of in-can spoilage and product recalls.
• Supplier Assessment: Paint manufacturers can evaluate incoming raw materials for microbial quality to ensure supplier compliance and minimize contamination at the source.
• Facility Maintenance: Identifying high-risk contamination points in the plant helps focus cleaning, disinfection, and biocide use, improving overall plant hygiene protocols.
• Preservative Efficacy: Verifies that in-can preservatives are functioning adequately and microbial resistance is not compromising product integrity.
• Regulatory Compliance: Assists in aligning manufacturing processes with international trade and safety requirements as outlined by the WTO Technical Barriers to Trade (TBT) Committee.
• Incident Investigation: Provides a structured method for root cause analysis following spoilage incidents, aiding quick identification and corrective action.

Related Standards

• ASTM D2574 – Standard Test Method for Resistance of Emulsion Paints in the Container to Attack by Microorganisms
• ASTM D6007 – Standard Test Method for Determining Microbial Contamination of Paint Applicators Used in Field Applications
• ISO 4623 – Paints and Varnishes - Determination of Resistance to Microbial Growth
• ASTM E1259 – Standard Practice for Evaluation of Antimicrobials in Paint Products

Summary

ASTM D5588 is a vital standard for the paints and coatings industry seeking reliable methods for microbial condition determination in raw materials, finished product, and plant facilities. By systematically identifying contamination sources, manufacturers can ensure paint quality, optimize use of biocides, and maintain robust plant housekeeping practices. The test method is accessible to facilities of all sizes and underpins continuous improvement in product integrity and process control within paint manufacturing environments.

Key SEO keywords: microbial contamination in paint, ASTM D5588, paint quality control, paint raw materials, plant housekeeping, microbial testing standard, aseptic sampling, paint preservative effectiveness.

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5588 − 97 (Reapproved 2021)
Standard Test Method for
Determination of the Microbial Condition of Paint, Paint Raw
Materials, and Plant Areas
This standard is issued under the fixed designation D5588; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ing plant. There is a need for a simple method to determine the
presence or absence of microorganisms in plants that manu-
1.1 This test method covers a procedure for the determina-
facture paints and coatings. Such a determination enables the
tion of the microbial condition (contamination or sterility) of
manufacturer to establish the point of contamination (that is,
raw materials used in the manufacture of paint, and the
raw materials or problem housekeeping areas in the plant) to
microbial condition of paint and paint manufacturing areas.
help in solving the spoilage problem.
1.2 The values in SI units are to be regarded as the standard.
NOTE 1—Some contamination in plant areas is to be expected, since
The values given in parentheses are for information only.
microorganisms are ubiquitous and cannot generally be eliminated prac-
1.3 This standard does not purport to address all of the
tically (it is what an in-can preservative is supposed to control). Excessive
levels of contamination or contaminated raw materials can exceed the
safety concerns, if any, associated with its use. It is the
capability of the preservative. If you have excessive contamination in the
responsibility of the user of this standard to establish appro-
plant, there are methods for decontamination including steam,
priate safety, health, and environmental practices and deter-
preservatives, bleach, etc. These should be discussed with your biocide
mine the applicability of regulatory limitations prior to use.
supplierandusedwithcare.Recoveryofspoiledorcontaminatedproducts
1.4 This international standard was developed in accor-
is often not feasible, so an adequate level of the appropriate biocide in
conjunction with good plant housekeeping practices are essential. Your
dance with internationally recognized principles on standard-
biocide supplier can also help here.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.2 This test method may be used by persons without basic
mendations issued by the World Trade Organization Technical microbiological training, but some training on aseptic tech-
Barriers to Trade (TBT) Committee. niques would be recommended.
NOTE 2—The reliability of the results obtained from this test method is
2. Summary of Test Method
extremely dependent on the techniques employed. Improper techniques
can result in a sterile sample appearing to be contaminated, and even
2.1 This test method outlines procedures to (1) obtain
worse, a contaminated sample appearing to be sterile (see also 5.1). It is
samples for sterility testing from wet or dry materials and plant
recommended that you consult with your biocide supplier, raw material
sites, (2) conduct the sterility testing on those samples to see if
supplier, or an independent testing laboratory to confirm questionable
they are contaminated, (3) evaluate the degree of
results.
contamination, if any, and (4) provide a guide for some
indication of the type of contamination present (bacterial, 4. Apparatus and Materials
fungal, yeast, etc.). This test method is not designed to include
4.1 Balance, capable of weighing to 0.10 g.
all the necessary precautions to maintain the level of sterility
4.2 Incubator, or other device capable of maintaining a
required to provide the most accurate results. Some familiarity
constant temperature between 28 and 32°C.
with microbiological techniques is recommended.
4.3 Refrigerator.
3. Significance and Use
2 3
4.4 Tryptic Soy Agar (TSA) Plates, pre-prepared. (See
3.1 Spoilage of paint in the container is often related to the
Note 3).
use of contaminated raw materials, water (particularly recycled
washwater), vessels, piping, and equipment in the manufactur-
Please note that Tryptic Soy and Trypticase Soy are names used interchange-
ably. Pre-prepared TSA plates, BBL# 21185, are available from various microbio-
This test method is under the jurisdiction of ASTM Committee D01 on Paint logical supply companies.
and Related Coatings, Materials, andApplications and is the direct responsibility of Agar plates (media) may be purchased pre-prepared using the indicated Difco
Subcommittee D01.28 on Biodeterioration. or BBL number from microbiological supply companies, or both. Media may also
Current edition approved Nov. 1, 2021. Published November 2021. Originally be prepared from the formulations given in the Difco Manual (Difco Laboratories,
approved in 1994. Last previous edition approved in 2017 as D5588 – 97 (2017). Detroit, MI) or from appropriate dehydrated media using standard microbiological
DOI: 10.1520/D5588-97R21. techniques.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5588 − 97 (2021)
4.5 Potato Dextrose Agar (PDA) Plates, or Malt Agar 5.4 Liquid materials may be sampled as outlined in Section
Plates, acidified to pH 3.5 with lactic acid, pre-prepared. 6. Alternately, a sterilized container may be used to transport
the liquid sample to the sterile testing area. Be sure that no
NOTE 3—If preparing plates, Tryptic Soy Agar media with TTC
non-sterile items contact the liquid sample during sampling,
(triphenyltetrazolium chloride) indicator dye may also be used. In general,
the TTC helps visualize contamination, but it has been reported on handling, and movement to the testing area (for example, use
occasion to inhibit the growth of some bacteria. Interferences from
sterile pipet, etc. for transfer of material to container, etc.).
pigments in materials being tested may make the color change difficult to
see. If self-prepared plates are used with the TTC indicator, 0.01 % TTC 5.5 Dry materials may be sampled as in 6.3 or 9.1.To
indicator should be used and it must be added after autoclaving.
sample unopened, dry raw materials in bags, wipe a large area
of the outside of the bag clean with a clean rag or paper towel.
4.6 Lactic Acid.
Using a clean knife, cut open the bag within the cleaned area.
4.7 Sterile Swabs in tubes, pre-prepared.
Sample as in 9.1, or using a sterile tongue depressor or sterile
4.8 SwabTubes,CulturetteTubes, or a similar system (swab
spatula, scoop 10 to 15 g into a sterile plastic bag, close and
in a test tube with a transport medium) , all sterile, pre-
seal bag for transport to sterile testing area.
prepared can be used if transport of collected samples to the
NOTE 4—To decrease the chances of inadvertent contamination, a
laboratory testing area is required.
suggestion would be to carefully wipe the area of the bag to be cut, and
4.9 Sterile Diluent (9 mL) in tubes, pre-prepared (0.85 %
the knife used for cutting it, with isopropyl alcohol. Warning: Exercise
saline or other suitable diluent). These can be prepared from
care to avoid skin contact, since the isopropyl alcohol could carry
hazardous materials through the skin. Also, avoid excess alcohol that
sterile tubes and sterile saline solution then stored in a
could affect test results.
refrigerator.
5.6 When testing open containers of raw materials, vats,
4.10 Laminar Flow Hood, Sterile Room, or at least a
drums, etc., there is no need to sterile equipment surfaces (see
laboratory testing area that is relatively clean, free of blowing
Section 6). However, be aware that any contamination ob-
dust and dirt, etc., which can be used for streaking plates.
served may have been introduced after opening. Samples taken
4.11 Antiseptic Solution, to help maintain sterility of testing
from equipment surfaces that show contamination do not
area surfaces (4.10) (For example, 70 % ethanol solution.).
necessarily mean that the material contained or being manu-
4.12 Plastic or Rubber Laboratory Gloves, optional, steril-
factured inside is also contaminated.
ized.
6. Sampling Procedure for Plant Areas
4.13 Facial Mask, optional.
4.14 Sterile Spatulas or Sterile Tongue Depressors, 150-
6.1 Establish a protocol for surveying probable areas of
mm, (6-in.) individually wrapped. contamination. Make sure that such areas include pipes and
hoses, especially if left with water standing, any storage and
4.15 Plastic Bag, sterile.
mixing vessels, pumps, drains, sumps, etc. Because recycled
washwater is particularly susceptible to contamination, be sure
5. General Sampling Guidelines
to include it.
5.1 Take all reasonable precautions to avoid microbial
contamination while obtaining samples. You may choose to
6.2 Sampling is best carried out when the area to be tested
wear a facial mask and sterilized gloves. (Warning—Do not
is wet. In wet areas, the swab is dipped into or wiped on the
touch the swab anywhere near the cotton tip, or near parts of
area (see Note 3), and then returned to a sterile tube (with or
the swab which could be immersed in the test sample.
without transport media). This swab is then used for testing as
Microorganisms from the skin, clothing, and even air if
described in Section 8 (see also Section 7).
exposed too long, can contaminate the sample. If the swab has
6.3 Sampling dry areas provides information that is less
a cap, do not touch any part of the swab except that cap.
conclusive, but can be carried out by swabbing the dry area
Confirm suspicious results with additional testing.)
with a sterile swab that has previously been dipped into sterile
5.2 Use a new sterile swab, tongue depressor or spatula for
diluent. This swab is then used as described in Section 8.
each sample. Do not reuse any sampling devices. If using
gloves, dispose after use.
7. Testing Transported Samples
5.3 When taking samples, be sure to minimize the time
7.1 Iftransportofcollectedsamplestothelaboratorytesting
sterile items are exposed to the air to avoid false contamination
area is required, then use the swab contained in the swab tubes,
results.
culturette tubes, or similar system (swab in a test tube with a
transportmedium),inplaceofthedryswabasdescribedin4.7.
Any transport medium transferred to the agar or broth should
Pre-prepared plates available are Difco # 4360-22-0, or BBL # 96272. These
pre-prepared plates are not acidified to pH 3.5, but may be used (see also Footnote
not adversely affect the results.
3).
Pre-prepared plates available are Difco # 4265-22-6. These are not acidified,
7.2 Test swabs in tubes without media as soon as possible to
but may be used (see also Footnote 3).
avoid drying of swab and possibly killing any contaminating
Available from microbiological supply companies. Swab tubes or culturette
microorganisms. Test swabs in tubes with media within the
tubes 9345 with Amies medium were used.
Sterile plastic packs are available from microbiological supply companies. time specified by the manufacturer (generally 48 to 72 h).
D5588 − 97 (2021)
8. Testing Procedure for Liquid Samples or Swabs, or 10.2 Fungal contamination is generall
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