use and temperature differential or water temperature, so that this set of conditions could be considered in recommending test procedures. The performance level could then be set from test results on materials with known service performance. Further development work should be planned with a view to the possible recommendation of an alternate hot-and-cold-water exposure test that could be used to combine the prolonged hot-water exposure test recommended in section 2.18 and the thermal-shock test discussed above. 2.22. Resistance to Household Chemicals (C501) a. Purpose and Scope The purpose of this test is to evaluate the resistance of bathroom plumbing fixtures to chemicals with which they are likely to come into contact during normal use. b. Recommended Test Method (1) Equipment The test for resistance to household chemicals shall be made using test equipment prepared in accordance with figure 2.22-1. (2) Chemicals The resistance to attack by 20 different chemicals shall be evaluated. The chemicals that shall be used together with their required purity, concentration, and method of preparation are listed in table 2.22-1. NOTE: Such items as soap, mineral oil, and pine oil are considered as chemicals for the purpose of this test. (3) Test Procedure Cut five flat 4-in square specimens from the fixture to be tested and number these specimens from one through five. Clean each specimen with 1 percent by weight tri-sodium phosphate solution and cellulose sponge, rinse thoroughly with water, and dry. Next, position specimen No. 1 into the testing assembly as illustrated in figure 2.22-1 (F). Tighten screws with a firm pressure to prevent leaking. Then, with the cell in a horizontal position, add 0.5 ml of chemical No. 1 to cell No. 1, 0.5 ml of No. 2 to cell No. 2, 0.5 ml of No. 3 to cell No. 3, 0.5 ml of No. 4 to cell No. 4. Use a hypodermic syringe to introduce the chemical into the cell through the needle holes in the Teflon cover sheet (fig. 2.22-1, part C). Insert Teflon plugs into each of the four holes in the top plate (fig. 2.22–1, part A). After 2 hr 5 min at 75 ± 5 °F, dismantle equipment, remove specimens, and rinse with water. Immediately after drying, inspect test areas for evidence of attack and assign a chemical-resistance rating to each test area in accordance with the rating system specified in table 2.22-2. Next, repeat the same test procedure with specimens No. 2, and chemicals No. 5, 6, 7, and 8. After assigning resistance ratings, follow the same procedure with specimens No. 3, 4, and 5 and thus obtain a resistance rating for all 20 chemicals listed in table 2.22-1. The household chemicals resistance rating for the fixture shall then be the arithmetic average of these 20 individual ratings. (4) Information to be Reported Include the following in the test report: 1. Effect observed for each test area. 2. Household chemicals resistance rating for each of the 20 chemicals. 3. The household chemicals resistance rating for the fixture. c. Test Results and Discussion (1) Discussion of Existing Methods Few tests exist for evaluating the resistance of sanitary ware materials to common household chemicals. The commercial standards for porcelain-enameled bathtubs (CS 77-63, cast iron [4]; and CS 144-47, pressed steel [28]) include a requirement for resistance to citric acid, a chemical TABLE 2.22-1. Chemicals to be used in household chemicals test and reasons for their selection Principle chemical 5 Ethyl acetate. Carbon tetrachloride. ingredient Reagent. Reagent Reagent. USP. Reagent. Full strength.. 15 Sodium bisulfhate. 12343 Ammonium hydroxide. Sodium hydroxide.. 20 Sodium nitrate.. ■ Commercial grade. b Ivory flakes, or equivalent. 2 g in 100 ml water. 6 percent by vol in water.. 0.1 g of soap shall be placed in Teflon ring before adding cover; 0.5 ml of Trials with the equipment showed that evaporation could be held to low levels even when such a volatile solvent as acetone was used as the test reagent. The test procedure that was devised through use of this equipment is described in section 2.22b (3). Test results when this procedure was used for three current fixture materials are listed in table 2.22-3. The household chemicals resistance rating TABLE 2.22-3. Results of household chemicals test for three sanitary ware materials Chemical Type of chemical FRPE a Porcelain- Porcelain enameled enameled cast iron steel bo 75 100 100 d 50 100 100 od 50 100 100 d 50 100 100 Carbon tetrachloride. 100 If more than one effect is present after treatment, the effect giving the lowest rating shall be the one used for assigning a rating to the test area. Also, all effects listed for one rating need not be present on the same test area. Thus, if a specimen showed a slight dulling of the surface with no evidence of pitting, etching or staining, the assigned rating would be 50. Likewise, if all three effects (etching, pitting, dulling, and staining) were present, the rating would be 50. 830 18 678 16 Sodium carbonate. 100 100 100 Ammonium hydroxide.. • 50 100 100 Sodium dodecylbenzene sulfonate. 100 100 100 120 19 Sodium hydroxide. Sodium nitrate... 100 No visible effect.... Fiber pattern in coating or indentation mark in coating from penetration of Teflon ring. Etching, dulling, pitting, or discoloration... Flaking, blistering, or peeling of coating... of the FRPE fixture material was 86 and that of both porcelain-enameled materials (cast iron and steel) was 100. (3) Rationale for Test Selection A test for resistance for household chemicals should incorporate a representative range of those reagents with which a bathroom fixture might come into contact during service. In selecting these reagents, staining media were not considered since a staining test is incorporated elsewhere herein (sec. 2.23). The selection of test chemicals was established on the basis of recommendations by members of the BRAB ad hoc committee. Some of the selections may be questioned. For example, the list includes pairs of chemicals of the same type but with different reactivities or solvent properties. One such pair is ethyl and isopropyl alcohols, and another is sodium hydroxide and sodium carbonate. Also, the list does not include chlorine bleaches, which are present in scouring powders and bleaching products. Another possible objection to the test method is that the chemical exposure occurs in a closed system. Under service conditions such volatile solvents as acetone, benzene, ethyl acetate, ethyl alcohol, and carbon tetrachloride would normally evaporate before attacking the surface. However, the rationale considered the possibility that such solvents, as well as other chemicals, might be trapped between the fixture surface and the bottom of a container. The chemical might be spilled initially on the surface of the fixture, the container might leak, or the bottom of the container might become wet due to carelessness in pouring. The container might then be set down on the surface, trapping the chemical underneath and maintaining a ring of pressure around the contour of the bottom of the container. The test time of two hours is arbitrary. Either a longer or shorter time might have been used. However, two hours is believed to be realistic since only on very rare occasions would household chemicals (with the possible exception of wet soap) be in contact with a fixture for a longer period. The method of grading the test areas assigns a resistance rating based on the severity of the attack. A material that shows no effect from a given chemical should obviously have a higher rating than one that shows an effect. Likewise, a material that shows only a very slight effect (fiber pattern in coating or a softening as evidenced by penetration of the Teflon ring) should be rated higher than one in which the attack is so severe that the substance is exposed after treatment. The rating system specified in table 2.22-2 incorporates this concept of differences in the degree of attack. d. Comments on Performance Requirements (1) Suggested Format for a Performance Level The household chemicals resistance_rating for the fixture shall be not less than __. In addition the individual resistance rating to chemical No. 10 (soap) shall be not less than 100, nor shall the ratings be less than for chemicals No. 6 (isopropyl alcohol), No. 12 (phenol), No. 13 (hydrogen peroxide), No. 17 (ammonium hydroxide), No. 19 (sodium hydroxide), or No. 20 (sodium nitrate). (2) Rationale for Suggested Format The household chemicals resistance rating of the FRPE specimens tested was 86. The field survey, made at the beginning of the investigation, indicated that the present gel-coat materials have a sufficient resistance to household chemicals since. there was no evidence of chemical attack on any of the fixtures nor were any complaints offered by homeowners about the lack of chemical resistance. Future sanitary ware materials may not have as good a resistance as current FRPE fixtures. Therefore, some considerations should be given to setting the performance requirement at 75 to insure that newly introduced materials will not be seriously deficient with respect to their resistance to common household chemicals. Consideration of the 20 chemicals listed in table 2.22-1 will suggest that some of these chemicals are much more frequently encountered than others and therefore more important to the test. This is the reason for suggesting specific levels for specific chemicals. It would be unreasonable, for example, to permit the use of a fixture material that had poor resistance to attack by wet soap. A performance level requiring a resistance rating of 100 for wet soap would prevent the use of such a material. The levels for chemicals No. 6, 12, 13, 17, 19, and 20 might be set lower; possibly as low as 50. 2.23. Stain Resistance (C502) a. Purpose and Scope The purpose of this test is to evaluate the ease of removal of stains from both "new" and "abraded" surfaces of such sanitary fixtures as bathtubs, shower stalls, and lavatories. b. Recommended Test Method (1) Equipment and Staining Agents The following equipment is required for performing the stain test as herein described: 1. Brass cover blocks prepared in accordance with figure 2.23-1. 2. One-inch diameter watch glasses. 3. Rubber O-rings, % in O.D. by 11/16 in I.D. In addition the following staining solutions are required: Stain No. 1. Five-percent solution (by weight) of reagent-grade potassium permanganate in distilled water. Stain No. 2. One-percent solution (by weight) of iodine in ethyl alcohol. Stain No. 3. Mercurochrome in ammonia; prepare by mixing one volume of a two-percent aqueous solution of Mercurochrome (merbromin) with two volumes of concentrated ammonium hydroxide. NOTE: The Mercurochrome solution may be that commonly sold in pharmacies as a general antiseptic. Stain No. 4. Iron-staining medium; two ingredients are required: (1) Chemical-grade ironmetal filings, degreased, 20 mesh and finer, Allied Chemical Company, Code 1810, or equivalent, and (2) A one-percent solution (by weight) of sodium chloride in water. These two ingredients are combined immediately prior to use as specified in paragraph 2.23b (2). (2) Test Procedure Select at random eight 11/2-in-diam areas of the fixture that are substantially flat and horizontal. If the fixture has no such areas, the fixture may be tilted, or alternatively, flat specimens may be cut from the fixture. Abrade four of the selected test areas with 400 C silicon carbide abrasive paper (Carborundum Company A955R, or equivalent). Use strips of the paper that are approximately 1/2 in wide and 1 in long. Place one end of the paper under the index finger and with a firm pressure (force of approximately 10 lb) abrade the area to be tested for a total of 10 strokes (five forward and five backward) in one direction, and then with the index finger over the opposite end of the strip, abrade for 10 strokes in a direction at right angles to the first direction. The area where the two abrasion treatments intersect (roughly 1/2 in2) is the area to be used for evaluating the stain resistance of an abraded surface. Prior to application of the staining solutions wash all test areas (abraded and unabraded) with soap and water, rinse thoroughly, and dry. Place approximately 0.5 ml of Stain No. 1 solution on unabraded area No. 1, cover with a 1-in-diam watch glass, and finally cover with the brass cover block (fig. 2.23-1) to prevent excessive evaporation. After 2 hours at 75 ± 5 °F, remove the brass block and watch glass, and also remove excess staining solution by blotting. (NOTE: If the test area is dry on removal of watch glass, the test is void and shall be repeated). Allow the test area to stand after blotting until it is visually dry and then grade for ease of removal of residual stain in accordance with the rating system specified in table 2.23–1. Next, repeat all operations specified in the preceding paragraph for Stains No. 2 and No. 3. NOTE: For Stain No. 3 cover inside surfaces of brass cover block with a layer of stop-cock grease to prevent corrosion of the brass by the ammonia vapor. (1) Use a fresh, unused pad of soft, lint-free cheesecloth for each rubbing treatment specified in table 2.23-1(A). Each pad shall be approximately one inch square and shall consist of not less than five layers of the cloth. (2) For each rubbing treatment, place the pad under the index finger and with a firm pressure (approximately 10 lb total force), rub for the specified number of strokes. One stroke shall consist of either one forward or one backward movement of the pad over the stained area. (3) In all wet rubbing teatments, excess fluid shall be removed from the pad prior to use. (4) Each treatment specified shall be applied to the stained area in sequence until there is no further visual evidence of discoloration, or until Treatment H has been completed. The numerical rating shall correspond with the final treatment that removed the discoloration, or if some discoloration remains after Treatment H, it shall correspond with the intensity of the residual staining. (5) Stains retained in small scratches that may accidentally be present on the unabraded specimens shall not be considered in assigning stain ratings. For Stain No. 4 (iron stain), spread 0.1 g of the iron filings uniformly over a 3/4-in.-diam area of the test surface and surround the iron with a %-indiam O-ring that has been cleaned with scouring powder prior to use. Wet the iron with 0.1 ml of the 1-percent sodium chloride solution and cover with a brass block (fig. 2.23-1). Apply an excess of stop-cock grease to the brass block O-ring to insure a tight seal. After 20 hrs at 75±5 °F, remove the brass block and -in-diam O-ring, and allow residual solution to dry without blotting. If test area is dry on removal of the brass block, improper sealing has occurred and the test shall be repeated. Grading of the iron stain shall be done within one to four hours after removal of the brass block. Prior to grading, remove excess iron from test area by brushing. Assign stain rating as specified in table 2.23-1. Evaluate the stain ratings of the abraded areas by the same test procedures and the same rating system used for the unabraded surfaces. For the abraded-area tests, the watch glass (or the O-ring for the iron stain) shall be so positioned that the outer edge of the watch glass (or O-ring) falls on the center of the abraded area. The combined stain rating shall be the sum of the rating for the eight individual stains (four stains on the unabraded and four on the abraded areas) divided by eight. This combined rating need not be reported to more than two significant figures. (3) Information to be Reported Include the following in the test report: 1. Assigned rating for each stain on the unabraded areas. 2. Assigned rating for each stain on the abraded areas. 3. Combined stain rating for the fixture. c. Test Results and Discussion (1) Discussion of Existing Tests Two test procedures have been used for evaluating stain resistance. The first, which is for the "Formica" type of material, is included in ASTM Designation: D1300–53T [11]. It specifies that the material shall be unaffected by tea, beet juice, vinegar, bluing, dye, ink (washable), iodine (1 percent), and Mercurochrome (2 percent) except for superficial staining which can be easily removed by a light application of a mild abrasive. The test is highly qualitative and vague in its wording. In addition, it gives the test operator considerable leeway in selecting the particular proprietary products that he chooses to use. The proposed revision of CS 221-59 [1] contains a stain test specifically designed for FRPE sanitary fixtures. Although this test has some desirable features, it was not believed suitable for a performance test since (1) it uses proprietary materials for stains, (2) the abrasive pretreatment is not sufficiently severe to have any measur able effect on porcelain-enamel or vitreous-china finishes, (3) the material with the poorest stain resistance is assigned the highest stain rating, and (4) iron stains, which are quite common on sanitary fixtures, are not included as one of the staining media. (2) Test Development and Rationale for Test Selection The premises used for devising a staining test that would be free of most of the aforementioned objections were as follows: 1. Since it would be impractical to test a fixture material with every conceivable stain with which it might come into contact, it seemed necessary to select several representative types of stain for the standard test method. 2. Because proprietary products could change in composition at any time depending on the needs of the manufacturer to maintain a market, and also because these products could at some future time disappear completely from the market, the specified staining agents should be well-specified chemicals rather than proprietary products of uncertain composition. 3. With the possible exception of iron and copper discolorations, stains on fixtures are usually not the result of long-time contact but rather are caused by accidental spills or other short-time exposure to the staining agent. 4. Because the surfaces of all fixtures become roughened to varying extents during normal use, the stain resistance after a roughening treatment is of considerable interest to the user. However, it is only logical that the same roughening treatment be applied to all materials. Also, it seems logical that the selected treatment should be sufficiently severe to cause at least some roughening of the most abrasion-resistant finish. 5. The stain rating should be related to the ease with which a stain can be removed through use of common household cleaning agents. 6. The stain test should be so designed as to provide numerical ratings for stain resistance so that (a) performance levels can be more easily assigned, and (b) manufacturers can more readily ascertain when they have improved the overall stain resistance of their product. (a) Selection of Staining Agents One of the major problems encountered in the development of a stain test was the selection of the staining agents. The following stains were investigated: 1. Iron stain. Trials with solutions prepared from soluble iron salts all gave negative results. In no case was an adherent stain formed on any of the materials. However, when metallic iron was permitted to rust while resting on the fixture, surface stains were produced that closely resembled those that are sometimes observed on installed fixtures. The problem then became one of generating |