6.1.2. Weighing of arsenic

to lower sigma metrics for the Low control (Figure 9). High control is easier to pass the %CV

Before participating in the EQA program, another way to evaluate the nation's urinary iodine laboratories was through inter-laboratory comparison. Some analyzed respondent samples were chosen from a wide range of urinary iodine concentrations and the same samples were analyzed again by another urinary iodine laboratory by using the same method. The results were compared between the laboratories and biases were determined. Any discrepancies were then discussed and trouble-shooting to problems was

Safety and waste management is very important and included in the quality management system. All Material Safety Data Sheets (MSDS) for every chemical used were printed out and kept in a designated file for reference. The information is used for self-awareness and protection, waste labeling and in any spillage incidences. Wearing proper personal protec-

One of the chemical used in the UIMM is arsenic (III) oxide. It is categorized as highly toxic. Thus, safety precautions ought to be made along the way from purchasing, storage, analytical stages until waste disposal. The safe procedure to weigh arsenic is as discussed below as reference to all operators. Its storage should be in a locked containment with records of its

The properties of UIMM chemicals and precautions that should be taken while handling them

Potassium iodate (toxic substance) The concentration of the working solution is not exceeding

be taken

Avoid direct contact to skin or inhalation

hazardous limit but precautions while handling it ought to

tive equipment (PPE) should be a culture in the urinary iodine laboratory.

date and time it is being taken out and name of the operators handling it.

Ammonium persulfate (oxidizing substance) Avoid direct contact to skin or inhalation Ceric ammonium sulfate (toxic substance) Avoid direct contact to skin or inhalation

H2SO4 (corrosive substance) Avoid direct contact to skin or inhalation

Table 3. Chemical properties and precautions when handling UIMM chemicals.

limit set by both EQA providers (Figures 8 and 9).

6. Safety and waste management

6.1.1. Know your urinary iodine chemicals

Arsenious acid solution (highly toxic substance) (containing sodium chloride, sodium hydroxide, arsenic

Chemical (properties) Precaution

are as stated in Table 3.

(III) oxide and sulfuric acid)

carried out.

84 Quality Control in Laboratory

6.1. Safety

	- a. one is empty
	- b. one is filled with 20 ml dH20

## 6.1.3. Other safety precautions


#### 6.2. Waste management

