NCCLS/CAP
Specifications for Reagent Water  (reads best (I hope) if viewed with screen
to full size)


TYPE I                 TYPE II     TYPE III

MAXIMUM MICROBIALCONTENT (CFU/ML)
(Colony Forming Units per milliliter)                            10
1000           n/a

MINIMUM RESISTIVITY(MEGOHM-CM)           >10 (IN-LINE)      >1.0
n/a
(or Conductivity in micro-ohm)                                   < 0.1
<1.0            n/a

MAXIMUM SILICATE CONTENT (MG/L SIO2)     0.05                         0.1
1.0

PARTICULATE MATTER                                     0.22 um FILTER
n/a             n/a

For histology, glassware can be washed in Type III water, but final rinse
must be in Type II
(or Type I). Type III water is tap water.

All other water for histology and IM can be in Type II, which is the
deionized water that
comes from the deionizer, usually in the power house of the hospital. So
Type II must
be used to make staining solutions, rinse slides between stains, rinse all
glassware and
coplin jars after washing, etc.

Type I water is usually reserved for some areas of clinical pathology that
must have
the purest water, such as the machines in chemistry, or some molecular
pathology
techniques. Usually microbiology also uses Type I water for making cultures,
etc.
For Type I, the lab must have an in-line filter near the machine, in
addition to the
deionizer in the powerhouse.

There is also "special water" that is used, such as the sterile water used
in
cytogenetics to grow their cells.

So histology and immunology must have a minimum of Type II water, but if
you have Type I, even better.

(BTW - who is measuring/testing the quality of your different water types,
and how are they testing it?)

Peggy A. Wenk, HTL(ASCP)
William Beaumont Hospital
Royal Oak, MI 48073

----- Original Message -----
From: "Horn, Hazel V" 
To: 
Sent: Monday, August 27, 2001 12:37 PM
Subject: types of water


> Hello all,
> We are having a CAP inspection and I need to know what type of water is
> really required for CAP.    We use Type I but one of the laboratory
> supervisors wants a written procedure that requires my use of Type I
water.
> I have assumed Type I water is Distilled Water.   Is this correct?   We
also
> have available Type II and III water.   Can someone enlighten me??
> Thanks,
> Hazel
>
>