ASTM E825-98(2023)

Standard Specification for Phase Change-Type Disposable Fever Thermometer for Intermittent Determination of Human Temperature

ABSTRACT
This specification covers the test methods and corresponding requirements for phase change-type disposable (for one time use only) clinical thermometers used for the intermittent determination of human temperature. When examined using the test methods suggested herein, sampled specimens shall comply with the specified requirements as to temperature range and graduation, accuracy, measurement retention, operating environment, storage environment, toxicity, workmanship, stability, and marking and labeling.
SCOPE
1.1 This specification covers phase change-type clinical thermometers that are designed and intended for one-time use.  
1.2 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.

General Information

• Status: Published
• Publication Date: 31-Jan-2023
• ICS: 17.200.20 - Temperature-measuring instruments
• Technical Committee: F04 - Medical and Surgical Materials and Devices
• Drafting Committee: F04.33 - Medical/Surgical Instruments

Relations

• Refers: ASTM E344-23 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-Dec-2023
• Refers: ASTM E344-19 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-Sep-2019
• Refers: ASTM E344-18 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-Apr-2018
• Refers: ASTM E344-16 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-Nov-2016
• Refers: ASTM E344-13 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-May-2013
• Refers: ASTM E344-12 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-May-2012
• Refers: ASTM E344-10 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-Nov-2010
• Refers: ASTM E344-08 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 15-Nov-2008
• Refers: ASTM E344-07 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-Jun-2007
• Refers: ASTM E344-06 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 01-May-2006
• Refers: ASTM E344-02 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 10-Oct-2002
• Refers: ASTM E344-00 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 10-Oct-2001
• Refers: ASTM E344-01 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 10-Oct-2001

Overview

ASTM E825-98(2023) sets out the specification for phase change-type disposable fever thermometers designed for intermittent human temperature measurement. This international standard provides requirements and test methods to ensure the safety, accuracy, performance, and labeling of one-time-use clinical thermometers using phase change technology for body temperature assessment. Developed according to globally recognized guidelines, ASTM E825 ensures harmonized quality and reliability for disposable thermometry products used in clinical and personal healthcare settings.

Key Topics

• Product Scope: Applies specifically to clinical thermometers intended for single use, using phase change materials to visually indicate human body temperature.
• Accuracy and Graduation: Specifies strict accuracy requirements across defined temperature ranges (35–40.4 °C/96–104.8 °F), with graduation intervals no greater than 0.1 °C (0.2 °F).
• Measurement Retention: Ensures that temperature readings remain accurate for at least one minute after measurement.
• Operating Environment: Requires reliable function in temperatures from 18 to 33 °C (64 to 92 °F).
• Storage Conditions: Thermometers must retain specified accuracy after storage at extreme temperatures (−18 to 38 °C/0 to 100 °F) and varied humidity levels for the periods defined.
• Safety and Toxicity: Mandates that all components, including the phase change chemicals, are nontoxic and safe for contact with skin and mucous membranes.
• Marking and Labeling: Details required identification, usage instructions, explicit single-use indication, and clear statements for products with special temperature ranges or limitations.
• Quality Control: Includes sampling and testing methods to verify conformance for each manufacturing lot and batch.

Applications

ASTM E825-98(2023) is highly relevant for manufacturers, distributors, and healthcare professionals involved in:

• Medical and Healthcare Settings: Ensuring safe, accurate, and hygienic temperature measurement in clinics, hospitals, pharmacies, and point-of-care environments.
• Infection Control: Providing single-use, disposable thermometers that help reduce cross-contamination and infection transmission between patients.
• Patient Home Use: Offering reliable, easy-to-use temperature monitoring for consumers and caregivers, especially in situations where reusable thermometers are impractical.
• Emergency and Field Use: Supporting portable and contamination-free temperature measurement in disaster relief, military, and remote care situations.
• Procurement and Regulatory Compliance: Assisting buyers and regulatory agencies in verifying product quality and performance as required by international and national standards.

Related Standards

For further consistency and compatibility in thermometry and temperature measurement devices, the following related standards should be considered:

• ASTM E344: Terminology Relating to Thermometry and Hydrometry-provides foundational definitions referenced in ASTM E825.
• CFR Title 21, Section 191: U.S. regulatory requirements on medical device toxicity and labeling.
• International Temperature Scale of 1990 (ITS-90): Calibration reference for accuracy testing equipment.
• Relevant National Pharmacopoeias and Formulary Requirements: For biocompatibility and safety testing.
• Other ASTM Standards in Medical and Surgical Materials: For comprehensive requirements in medical device manufacturing and performance.

Conclusion

ASTM E825-98(2023) is a critical specification for phase change-type disposable fever thermometers, addressing essential requirements such as accuracy, safety, single-use design, and clear labeling. Adhering to this standard supports high-quality, reliable, and compliant disposable thermometers, enhancing patient safety and effective temperature monitoring in various healthcare environments. For product development, procurement, or regulatory assessment, referencing this ASTM standard is key to ensuring optimal performance and risk management in clinical thermometry.

Standards Content (Sample)

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: E825 − 98 (Reapproved 2023)
Standard Specification for
Phase Change-Type Disposable Fever Thermometer for
Intermittent Determination of Human Temperature
This standard is issued under the fixed designation E825; 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 3.2.3 measurement time, n—length of time required from
the time of patient contact to the time when the thermometer
1.1 This specification covers phase change-type clinical
may be removed to read within its stated accuracy.
thermometers that are designed and intended for one-time use.
3.2.4 predictive thermometer, n—any thermometer that pro-
1.2 This international standard was developed in accor-
vides an indication of the final stabilized temperature of the
dance with internationally recognized principles on standard-
measurement site in advance of the time for the sensing part of
ization established in the Decision on Principles for the
the thermometer to reach the equilibrium temperature of that
Development of International Standards, Guides and Recom-
site.
mendations issued by the World Trade Organization Technical
3.2.5 storage package, n—smallest package intended by the
Barriers to Trade (TBT) Committee.
manufacturer for long-term storage at the user’s facility.
2. Referenced Documents
3.2.6 suitable packaging unit, n—unit(s) of packaging to
2.1 ASTM Standards:
which a specific requirement of marking and labeling is
E344 Terminology Relating to Thermometry and Hydrom-
logically applicable. It shall not be less than the smallest unit
etry
intended for sale by the manufacturer or distributor to the final
2.2 Other Standards:
user.
National Formulary, Volume XIII Code of Federal
3.2.7 temperature offset, n—designed difference in predic-
Regulations, Title 21, Section 191, II 1971
tive thermometer readings and water bath test temperatures.
3. Terminology
4. Classification
3.1 Definitions—The definitions given in Terminology E344
4.1 Phase change disposable thermometers for the intermit-
apply.
tent determination of human temperature.
3.2 Definitions of Terms Specific to This Standard:
NOTE 1—The requirements of this specification shall not preclude the
3.2.1 intermittent determination of human temperature,
manufacture and sale of special thermometers having different tempera-
n—determination of human body temperature that is made
ture ranges and degrees of subdivision designed for specific medical uses.
periodically by a series of entirely separate measurements.
Packaging on any “special” thermometers shall state that the thermometer
is a special one intended for a specific use and, therefore, is not necessarily
3.2.2 manufacturing lot, n—in the case of a continuous
in compliance with this specification. In addition, the special thermometer
manufacturing process, a lot is a specific identified quantity or
must be marked in such a way as to identify it as “special.”
amount produced in a unit of time made in a manner that
4.2 Scales, Celsius and Fahrenheit.
ensures its having uniform character and quality within speci-
fied limits. In the case of a batch process, a lot means a batch
NOTE 2—The Fahrenheit temperatures given in parentheses throughout
or specific identified portion of a batch having uniform
this specification are not necessarily exact Celsius conversions but are the
character and quality within specified limits. values to be used when testing thermometers with Fahrenheit scales for
conformance with this specification.
This specification is under the jurisdiction of ASTM Committee F04 on
5. Requirements
Medical and Surgical Materials and Devices and is the direct responsibility of
Subcommittee F04.33 on Medical/Surgical Instruments.
5.1 General—All thermometers represented as complying
Current edition approved Feb. 1, 2023. Published February 2023. Originally
with this specification shall meet all of the requirements
approved in 1981. Last previous edition approved in 2016 as E825 – 98 (2016).
specified herein. Terms are defined in Section 3.
DOI: 10.1520/E0825-98R23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.2 Temperature Range—The instrument shall cover the
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
minimum range from 35 to 40.4 °C (96 to 104.8 °F) unless
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. otherwise obviously labeled. If any thermometer does not meet
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E825 − 98 (2023)
TABLE 2 Accuracy of Thermometers with a Fahrenheit Scale
the range 35 to 40.4 °C (96 to 104.8 °F), it shall additionally be
obviously marked as “Limited Range” on suitable packaging Temperature Range, °F Maximum Error, °F
units. Below 98 ±0.4
98 to 102 ±0.2
5.3 Accuracy—The accuracy of the thermometer shall be in
Above 102 ±0.4
conformance with Tables 1 and 2 when tested in accordance
with 6.2 at any point on the temperature scale of the thermom-
eter.
specific manufacturing lot. Suitable packaging units and other
5.4 Measurement Retention—A measurement meeting the
labeling shall also bear a statement that the thermometers are
accuracy requirements of 5.3 will be maintained for a mini-
intended for single use only.
mum of 1 min when tested in accordance with 6.2.4.
5.10.2 Operating Instructions—Operating instructions must
5.5 Operating Environment—When used in an environment be provided. When space limitations dictate, the operating
instructions on an individual thermometer may be omitted if
in which the temperature is in the range from 18 to 33 °C (64
to 92 °F), the thermometers, when tested in accordance with detailed instructions are provided on or with a suitable pack-
6.3, shall meet the requirements of 5.3. Any thermometer aging unit.
product not meeting this requirement shall be marked on a 5.10.3 Additional Marking and Labeling—Additional mark-
suitable packaging unit or other labeling of the thermometers ing and labeling that may be required by 5.2, 5.5, 5.8, 5.9, and
with a cautioning statement indicating the ambient temperature 6.2.3 shall be clear, concise, and adequate for the intended
range in which it can be used with specified accuracy. purpose. The temperature measurement offset shall be included
in the labeling of the thermometers.
5.6 Graduation—The thermometer shall be graduated in
intervals no greater than 0.1 °C (0.2 °F). As a minimum, 5.11 Toxicity—When the thermometer is used as specified
by the manufacturer, its parts intended for contact with
appropriate numerals shall be placed at every degree gradua-
tion for Celsius scale thermometers and at every even degree anatomical sites during patient use and its melting point
chemicals shall be nontoxic as determined by 6.5.
graduation for Fahrenheit scale thermometers.
5.7 Workmanship—There shall be no constructional defects
6. Test Methods for Performance Verification
that would prevent the measurement of temperature within the
6.1 Significance and Use—This section describes the
accuracy requirements of 5.3.
principles, apparatus, and procedures to be used to determine
5.8 Stability—Thermometers shall meet all requirements of
the conformance of disposable thermometers to the require-
this specification over their shelf life. If the shelf life of the
ments of this specification. Each manufacturer or distributor
product is less than five years when stored in compliance with
who represents his products as conforming to this specification
the manufacturer’s instructions, an uncoded expiration date
may use statistically based sampling plans that are appropriate.
shall be displayed on the labeling of the product.
He shall keep such essential records as are necessary to
5.9 Storage Environment—When tested in accordance with
document his claim that all the requirements of this specifica-
6.4, thermometers shall meet the requirements of 5.3 after they
tion are met. This section does not include any procedure for
have been stored for one day at any point in an environment of
requirements that can be verified by visual inspection (such as
−18 to 38 °C (0 to 100 °F) and at relative humidities from 15
5.2).
to 90 %. When tested in accordance with 6.4, thermometers
6.2 Accuracy Test:
shall also meet the requirements of 5.3 after they have been
6.2.1 Test Equipment Required—The test equipment shall
stored for one month at any point in an environment of 15.5 to
include constant-temperature
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