504.3-4 DISINFECTANT
Phenol based disinfectants can blister the skin; if toxic, they may cause poisoning by absorption through the skin or by inhalation of the vapors. Undiluted forms of certain disinfectants may be flammable. Use expert commercial disposal companies to manage disposal of detergents. Small quantities may be flushed down the drain with copious quantities of water.
4.1 Test Facility
Use a test facility that includes an enclosure and a temperature control mechanism designed to maintain the test item at a specified temperature, as well as a means of monitoring the prescribed conditions (see Part One, paragraph 5.18). The contamination facility is a tank or other container within the test enclosure (non-reactive with the contaminant) in which the test item is exposed to the selected contaminant by immersion, spraying, or brushing. When the flash point of the test fluid is lower than the test temperature, design the test facility in accordance with fire and explosion standards.
4.2 Controls
Record chamber and, if required, test item and test fluid temperatures in accordance with Part One, paragraphs 5.2 and 5.18, at a sufficient rate to satisfy the post-test analysis (see Part One, paragraph 5.18).
Ensure the test and cleaning (decontaminating) fluids are handled and disposed of as required by local environmental and safety requirements. Some test fluid specifications are referenced in Table 504.3-I.
4.3 Test Interruption
Test interruptions can result from two or more situations, one being from malfunction of test chambers or associated test laboratory equipment. The second type of test interruption results from failure or malfunction of the test item itself during performance checks (required or optional).
4.3.1 Interruption Due to Chamber Malfunction
- a. General. See Part One, paragraph 5.11 of this Standard.
- b. Specific to this Method.
- (1) Undertest interruption. If an unscheduled test interruption occurs that causes the test conditions to exceed allowable tolerances toward standard ambient conditions, give the test item a complete visual examination and develop a technical evaluation of the impact of the interruption on the test results. Restart the test at the point of interruption and re-stabilize the test item at the test conditions.
- (2) Overtest interruption. If an unscheduled test interruption occurs that causes the test conditions to exceed allowable tolerances away from standard ambient conditions, stabilize the test conditions to within tolerances and hold them at that level until a complete visual examination and technical evaluation can be made to determine the impact of the interruption on test results. If the visual examination or technical evaluation results in a conclusion that the test interruption did not adversely affect the final test results, or if the effects of the interruption can be nullified with confidence, re-
stabilize the pre-interruption conditions and continue the test from the point where the test tolerances were exceeded. Otherwise, see paragraph 4.3.2 for test item operational failure guidance.
4.3.2 Interruption Due to Test Item Operation Failure
5.12 Interruption Due to Test Item Operation Failure. Failure of the test item(s) to function as required during required or optional performance checks during testing presents a situation with several possible options. See Part One, paragraph 5.11 of this Standard.
- a. The preferable option is to replace the test item with a “new” one and restart from Step 1.
- b. A second option is to replace / repair the failed or non-functioning component or assembly with one that functions as intended, and restart the entire test from Step 1.
NOTE: When evaluating failure interruptions, consider prior testing on the same test item and consequences of such.
4.4 Test Setup
- a. General. See Part One, paragraph 5.8.
- b. Unique to this Method. Ensure collection containers are available for each test fluid and waste fluids.
4.5 Test Execution
The following test procedure may be used to determine the resistance or compatibility of the materiel to contaminating fluids. Conduct the functional checks after each exposure to each of the specified fluids.
4.5.1 Preliminary Steps
Before starting any of the test procedures, determine the test details (e.g., procedure variations, test item configuration, contaminating fluids, durations, parameter levels, etc.) from the test plan. (See paragraph 3.1 above.)
4.5.2 Pretest Standard Ambient Checkout
All test items require a pretest standard ambient checkout to provide baseline data. Examine munitions and other appropriate materiel by nondestructive examination methods. Conduct the checkout as follows:
- Step 1. Stabilize the test item at standard ambient conditions (Part One, paragraph 5.1).
- Step 2. Conduct a complete visual examination of the test item (evaluate against paragraph 2.1.1) with special attention to surface coatings and stress areas such as corners of molded areas and interfaces between different materials (e.g., component lead/ceramic interfaces of visible electronic parts), and document the results for comparison with post test data.
- Step 3. Conduct an operational checkout, where applicable, in accordance with the approved test plan and record the results for comparison with post test data. If the test item operates satisfactorily, proceed to the next Step. If not, resolve the problems and restart at Step 1, above. Where only parts are available, cut the part into appropriate sizes to accommodate all of the test fluids. Record any weight, hardness, or other physical data for each piece where appropriate.
- Step 4. Where applicable, prepare the test item in accordance with Part One, paragraph 5.8, and in the required test item configuration. Record initial baseline information with digital photography if available.
4.5.3 Cleaning
If necessary and, unless otherwise specified, clean the test item to remove unrepresentative coatings or deposits of grease. Be careful to ensure the cleaning compound will not interfere with the test, i.e., by leaving a residue to interact with test chemicals.
4.5.4 Multiple Fluids
If more than one contaminating fluid has been identified per test item, determine if each is to be evaluated simultaneously or sequentially. Where small items are used such as small arms ammunition, non-metallic materials, or pieces from a larger test item, use one test piece for each chemical. If sequential testing is required, specify in the requirements document any necessary cleaning method between tests for different contaminants. Check the supplier's material safety data sheet for chemical compatibility. Since contamination normally occurs with one fluid at a time, apply test fluids singly with appropriate cleaning of the specimen before applying subsequent fluids. If desired, clean the test item using a fluid listed as a 'contaminant' if its effect has been shown to be neutral, e.g., aviation fuel detergent.
Consider the possibility of simultaneous contamination by two or more fluids, especially if the result is expected to be synergistically more severe. Also consider the possibility of synergistic action resulting from consecutive contamination. In these cases, do not clean the test item between the applications of test fluids.
WARNING: READ ALL PERTINENT SDS INFORMATION ON ANY CHEMICAL PRIOR TO ITS USE. ADDITIONALLY, USE APPROPRIATE PERSONAL PROTECTIVE EQUIPMENT.
4.5.5 Procedure
- Step 1. Select the appropriate chemicals/solutions as per the test directive (chemicals may or may not be listed in Table 504.3. Prepare the test items.5 If etching will not affect the test item, number the parts to help with identification. Record the test item nomenclature, serial or lot numbers, manufacturer, chemicals/solutions, and any other pertinent test data.
- Step 2. Stabilize the test item at the appropriate temperature for the identified contamination scenario (see paragraph 2.2.5).
- Step 3. Stabilize the temperature of the specified fluid(s) to that determined from paragraph 2.2.5.2. If simultaneous application of more than one fluid is required, apply the fluid with the highest application temperature first, then the next highest, and so on until all required fluids have been applied.6
- a. Occasional Contamination.
- (1) Apply the specified fluid(s) (e.g., immerse, dip, spray, etc.) to the entire surface of the test item that is likely to be exposed.
- (2) Allow the test item to drain naturally for 5 to 10 minutes. Shaking or wiping is not permitted but, if representative of service conditions, it may be rotated about any axis to allow for drainage from different positions.
- (3) Where applicable, maintain the test item at the temperature determined in paragraph 2.2.5.1 for eight hours (paragraph 2.2.6). Ramp the chamber to standard ambient temperature at a rate not to exceed 3°C/min (5°F/min) prior to removal of test item(s).
- (4) Visually examine the test item for degradation of materials and surface finishes. Record any physical characteristics for comparison with previous results or if appropriate, conduct an operational check of the test item similar to that in paragraph 4.5.2, step 3, and document the results for comparison with the pretest data.
- (5) Clean the test item with a known fluid that will not cause any changes to the test item (Annex C).
If testing sequentially, repeat steps a (1) through (4) for each specified fluid without cleaning between each chemical application.
- b. Intermittent Contamination7,8.
- (1) Apply the specified fluid(s) (e.g., immerse, dip, spray, etc.) to the entire surface of the test item that is likely to be exposed. After one hour, visually inspect the test item/s for deterioration including softening, color changes, cracking, or dissolving of the material into the solution. If deterioration is observed, remove that item from the fluid and report
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the results after one hour. If no deterioration is observed, maintain surfaces in a wetted condition for a total of 8 hours followed by a drying period of 16 hours at the temperature specified in paragraph 2.2.5.1. If tested at other than standards ambient conditions, ramp the chamber to standard ambient temperature at a rate not to exceed 3C/min (5F/min) prior to removal of test item(s).
- (2) After 8 hrs of exposure to fluids, blot excess chemicals from the item, and inspect again for any type of chemical degradation of materials, surface finishes, and physical changes. After the drying period, record final measurements and weights, if any, and record final visual observations. Where applicable, maintain the test item at the temperature determined in paragraph 2.2.5.1 for eight hours (paragraph 2.2.6). Ramp the chamber to standard ambient temperature at a rate not to exceed 3C/min (5F/min) prior to removal of test item(s).
- (3) If appropriate, conduct an operational check of the test item similar to that in paragraph 4.5.2, step 3, and document the results for comparison with the pretest data.
- (4) Clean the test item with a known fluid that will not cause any changes to the test item. If testing sequentially, repeat steps b(1) through (4) for each specified fluid.
c. Extended Contamination
- (1) Immerse the test item in the specified fluid and maintain for the period specified in the requirements document. If not specified, immerse the test item for at least 24 hours.
- (2) Remove the test item from the chemical and allow it to drain naturally for 5 to 10 minutes.
- (3) Where applicable, place the test item in a chamber set at the temperature determined in paragraph 2.2.5.1 for eight hours (paragraph 2.2.6). Ramp the chamber to standard ambient temperature at a rate not to exceed 3C/min (5F/min) prior to removal of test item(s). Steps c (1) through (3) can be repeated if long term analysis is needed as per the test plan (record number of cycles performed).
- (4) After all cycles have been performed, visually examine the test item for degradation of materials, protective finishes, and physical changes and if appropriate, conduct an operational check of the test item similar to that in paragraph 4.5.2, step 3, and document the results for comparison with the pretest data record results.
- (5) If testing sequentially, repeat steps c (1) through (4) for each specified fluid.