Texas Comptroller of Public Accounts

Texas Comptroller of Public Accounts, Glenn Hegar

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Texas Specification No. 505-85-01A

Effective Date: June 18, 1979

Reformatted: January 29, 1996




(Silicofluoide and Acid Fluoride)

1. SCOPE: This specification covers the minimum requirements for a laundry sour used in laundry operations to neutralize the last traces of alkali in the load, and to prevent discoloration by rust stains.

2. APPLICABLE SPECIFICATIONS AND STANDARDS: References to specifications, standards and test methods shall be to the issues in effect on the date of the Invitation for Bids. Copies of the referenced documents may be obtained from the issuing organizations at the addresses shown. The following documents form a part of this specification to the extent specified herein:

2.1. AMERICAN SOCIETY FOR TESTING MATERIALS, 1916 Race Street, Philadelphia, PA 19103:

2.1.1. ASTM D 502 -- Standard Method of Test for particle Size of Soaps and Other Detergents.

3. DEFINITIONS: Terminology used in this specification is intended to be generic in nature and consistent with meanings that have been defined through general use and/or accepted trade practices. Where variant meanings may exist, the applicable interpretation shall be determined by the Texas Procurement and Support Services (TPASS).

3.1. Commission: Texas Procurement and Support Services (TPASS).

4. REQUIREMENTS: Laundry sour furnished under this specification shall meet or exceed the following minimum requirements:

4.1. General Requirements: The product shall be a free flowing, homogeneous, solid mixture of sodium silicofluoride and sodium acid fluoride, free from dirt or other objectionable impurities. There shall be no lumping or caking in the container when received or first opened.

4.2. Chemical and physical requirements: The chemical and physical properties listed in Table 1 shall fall within the indicated limits, when tested by the methods cited in Paragraph 6.



Requirement Minimum Maximum Test Paragraph
1. Sodium silicofluoride, pbw* 44 -- 6.1
2. Sodium acid fluoride, pbw* 44 -- 6.2
3. Total sodium silicofluoride plus acid fluoride, pbw* 95 -- 6.3
4. Insoluble matter, pbw* -- 1.0 6.40
5. Particle size:
% through No. 405 screen 95.00 -- 6.60
% through No. 325 screen -- 15.00 6.60
*pbw: percent by weight

5. SAMPLES: Unless otherwise specified in the Invitation for Bids, no prepurchase samples shall be required. Samples tested shall be taken from regular orders.

6. TESTING: Testing shall be done by or at the direction of, the Commission and/or the receiving State agency. Tests shall be performed on products from shipments to ordering agencies. In the event products tested fail to meet or exceed all conditions and requirements of this specification, the cost of the samples used and the cost of testing shall be borne by the supplier.

6.1. TESTS: The product furnished under this specification shall be tested by the following methods or equally applicable procedures:

6.1.1. Percent Sodium Silicofluoride: Prepare a KC1 solution by dissolving 60 grams potassium chloride in 400 ml distilled water, then adding 400 ml 95% ethanol. Weigh accurately a sample of about one (1) gram laundry sour into a small beaker made of a hydrofluoric acid resistant plastic such as Teflon or Nalgene. Add 50 ml KC1 solution, and stir until reaction appears to be complete. Collect the precipitated potassium silicofluoride on a Gooch crucible with a disk of filter paper and a medium pad of asbestos. Wash the precipitate with three or four portions of KC1 solution. Test the filtrate from the last portion iwht one drop each of 0.2 N NaOH and phenolphthalein indicator. If a persistent red or pink color is not obtained, continue washing. Transfer the contents of the crucible quantitatively to a 400 ml Pyrex beaker with the aid of at least 100 ml distilled water from a wash bottle. Add a few drops of phenolphthalein indicator. Place the beaker on a combination hot plate/magnetic stirrer, and heat the contents to the boiling point. Titrate with 0.2 N NaOH, finishing with the solution actively boiling. Calculate percent sodium silicofluoride by means of the expression:

% Na2SiF6 = ml NaOH x normality x 4.7

gram sample Determine complicane with Paragraph 4.2.

6.1.2. Percent Sodium Acid Fluoride: Weigh accurately about 0.5 gram laundry sour into a 250 ml beaker made of hydrofluoric acid resistant plastic. Add 100 ml distilled water and a few drops of phenolphthalein indicator. Titrate with 0.2 N NaOH until fading of the red color becomes slow. Transfer the contents of the beaker quantitatively to a 400 ml Pyrex beaker on a hot plate/magnetic stirrer. Continue the titration while heating and stirring. The solution should be boiling at the final end point. Calculate percent sodium acid fluoride by means of the expression:

% NaHF2 = [ (A x D) - (B x C) ] x 6.2



where A = ml NaOH used in the titration

B = gram sample

C = % Na2SiF6 from Paragraph

D = normality of NaOH Determine compliance with Paragraph 4.2.

6.1.3. Insoluble Matter: Stir a one gram sample of laundry sour for 30 seconds with one liter of water at room temperature in a large beaker. Filter immediately through a tarred Gooch or sintered glass crucible. Wash the beaker and crucible with plenty of distilled water. Dry the crucible to constant weight in an oven at 105 °C. Calculate percent insoluble matter, and determine compliance with Paragraph 4.2.

6.1.4. Particle Size: Determine the compliance with Paragraph 4.2 by the procedure of ASTM D 502, with the exception of the screen sizes required.

7. INSPECTION: Products furnished under this specification shall be inspected by, or at the direction of the Commission and/or the ordering State agency either at the destination or place of manufacture.

8. PACKING / PACKAGING: Packing for shipment shall be in accordance with the manufacturer's standard practice and in a manner readily accepted by common carriers engaged in interstate commerce. Within the shipping carton, units shall be packed in a manner designed to minimize damage during the shipment because of rough or improper handling.

8.1. PACKING: The product shall be packaged in one of the following types and sizes of new containers:

8.1.1. Multiwall paper bags of 100 pounds (45.4 kg) net contents.

8.1.2. Polyethylene lined fiber drums of from 100 pounds (45.4 kg) to 400 pounds (181 kg) net contents.


9.1. MARKING: Each shipping container shall be clearly marked with the following:

9.1.1. Name of contents.

9.1.2. Quantity contained.

9.1.3. Name and address of the manufacturer.

9.1.4. Warning statements as required by government regulations.

The following information shall either be marked on the container or appear on the shipping documents:

9.1.5. Order number or contract number.

9.1.6. Name and address of ordering agency.

9.1.7. Agency requisition number.

10. COMPLIANCE: In order for consideration to be given to the bid on an item under this specification, the bidder must comply with the following:

10.1. PRODUCT IDENTIFICATION: The make, model number, name of the manufacturer, brand or trade name, etc., as applicable, of the item which the vendor proposes to furnish must be stated as part of the bid.

10.2. EXCEPTIONS: Notwithstanding the above, any exception taken by the bidder to the requirements and conditions of this specification must be stated and described in detail as a part of the bid. If no exceptions or deviations are identified in this manner, the items must be furnished exactly as described herein.

10.3. PROOF: The bidder shall bear the burden of proof of compliance with this specification.

11. ORDERING DATA: When ordering products conforming to this specification the requisitioning agency shall specify the following:

11.1. The number of this specification (505-85-01A).

11.2. The type, size and number of containers.

11.3. The total quantity required.

12. PRODUCT INFORMATION: Laundry sour conforming to this specification neutralizes bicarbonate alkalinity without producing a pH below 4. It also prevents or removes iron rust stains. The amount used (approximately 1 1/2 ounces per hundred pounds of washload) should be adjusted to give the proper pH for the particular load (for example, 5.0 to 5.5 for colored wearing apparel and white apparel not requiring starch).

Since it contains soluble fluorine compounds, this product is very poisonous in concentrated form. Safety precautions should be taken in handling to prevent contact with the skin or inhalation of fine particles. In case of swallowing, call a physician. If a physician's immediate advise is not available, large amounts of milk may be given as a first aid measure.

13. AVAILABILITY OF SPECIFICATIONS: Copies of this specification may be obtained by calling or writing:

Bid Services

Texas Procurement and Support Services

P.O.Box 13186

Austin, TX 78711-3047

(512) 463-3416

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